Dotnetcoderoom Blog

Run JavaScript after page is loaded

dotnetcoderoom — Tue, 12 Apr 2011 09:36:55 +0000

If you need to call a JavaScript code when the html page is completely loaded, you can use JQuery.

At times some controls are not rendered and the JavaScript code runs, hence it is not able to find controls which is not rendered yet and client side code throws exception.

Use $(document).ready feature of JQuery as belows:

The above is also a replacement of the old body onload property: thing

Filed under: Asp.Net, JavaScript, JQuery Tagged: JavaScript, JQuery

Parameter is not valid. Asp.net GDI exception

dotnetcoderoom — Thu, 17 Mar 2011 09:32:19 +0000

I was getting this exception while working with the GDI images in asp.net.
My requirement was to upload the image from client then resize it and display.

The code was working fine on local development machine, but on production server it was throwing “Parameter is not valid” exception.

The general cause of this is that non-availability of resources required to generate a valid image file.

In my case the reason was that the destination folder was having read-only permissions, which was causing the code to hault while saving the processed image back to server.

For the resources I read during this issue, I found out some more reasons, these can be following:
1) Invalid source image path passed to the Drawing/Image/Bitmap object.
2) Invalid destination image path passed to the Drawing/Image/Bitmap object.
3) Corrupted/incomplete byte array.
4) Disposing of Source object before completing generation of new Image.
5) Folder write permissions while saving the new file.

Filed under: Asp.net Errors, Microsoft Visual Studio .Net Tagged: .net framework, Asp.Net, Asp.net Errors, GDI

Generic function to display images on webpage asp.net

dotnetcoderoom — Sat, 29 Jan 2011 09:29:24 +0000

Hi fellas,

I am writing this post after a long time. This new year I am back at blogging to help the software developers in writing better code .

Ever need of a generic/common function to display the images on website?
In normal practice, whenever we need to show an image, we used to directly write
Image.Src= “/userfiles/abc.jpg”;

This can be painful sometimes if your folder path gets changed, in that case you need to replace the folder (userfiles) everywhere.

Smart and better way is to create a common function that will display images. What you need to do is to call this method every time.

Method:

public string ShowImage(string ImageName)
{
string ReturnVal = string.Empty;

if (File.Exists(System.Web.HttpContext.Current.Server.MapPath(“~/userfiles/” + ImageName)) == true)
{
ReturnVal = VirtualPathUtility.ToAbsolute(“~/userfiles/” + ImageName);
}
else
{
ReturnVal = VirtualPathUtility.ToAbsolute(“~/Images/ImageNotAvailable.jpg”);
}

return ReturnVal;
}

Usage:

imgThumbnail.ImageUrl = ShowImage(“abc.jpg”);

Explanation:

This method, takes a string parameter as image name to display. Then it checks that if the particular image exists or not.
If the image exists on the specified path then it returns the image name with full path (userfiles/abc.jpg) else it returns the alternate image path, which is imageNotAvailable.jpg.

This way if the image is not founded on server then user will be shown a imageNotAvailable.jpg

Thats it for now.

Filed under: Asp.Net, Asp.Net Controls

2010 in review

dotnetcoderoom — Sun, 02 Jan 2011 06:40:57 +0000

The stats helper monkeys at WordPress.com mulled over how this blog did in 2010, and here’s a high level summary of its overall blog health:

The Blog-Health-o-Meter™ reads This blog is doing awesome!.

Crunchy numbers

The average container ship can carry about 4,500 containers. This blog was viewed about 17,000 times in 2010. If each view were a shipping container, your blog would have filled about 4 fully loaded ships.

In 2010, there was 1 new post, growing the total archive of this blog to 34 posts.

The busiest day of the year was August 30th with 97 views. The most popular post that day was Username Regex Validation.

Where did they come from?

The top referring sites in 2010 were forums.asp.net, google.co.in, stackoverflow.com, google.com, and velocityreviews.com.

Some visitors came searching, mostly for mssql rename column, operator ‘+’ cannot be applied to operands of type ‘string’ and ‘method group’, username regex, ms sql rename column, and rename column mssql.

Attractions in 2010

These are the posts and pages that got the most views in 2010.

Username Regex Validation October 2008

Operator + cannot be applied to operands of type string and method group, C# error September 2008
4 comments

Rename a table Column in MS SQL September 2008

ASp.Net 2.0 GridView Delete Button Confirmation pop-up August 2008
3 comments

Rotate a Label Text August 2008
1 comment

Filed under: Asp.Net

this._form is null or not an object, JavaScript Error

dotnetcoderoom — Mon, 15 Feb 2010 19:32:39 +0000

I was getting below javascript error everytime i run my visual studio asp.net web pages:

this._form is null or not an object

Because of this error all my AJAX controls and page postback stopped working.

As the error clearly states that it is a JavaScript error so i started checking all my Javascript code.

Finally searching on the internet i found the cause and cure of this problem.

Cause:

If you are including javascript files in the page header like an empty tag , like below :

Close the javascript tag properly and see the magic yourself.

Filed under: Html, JavaScript Tagged: Html, Java Script

Read Excel files using C-Sharp windows application

dotnetcoderoom — Wed, 24 Jun 2009 10:36:43 +0000

This article explains how to read excel files using c sharp in windows applications.

using System.Data.OleDb;

private void btnRead_Click(object sender, EventArgs e)
{
try
{
string connStr = connStr = “Provider=Microsoft.Jet.OLEDB.4.0;Data Source=” + Application.StartupPath + @”\Courier.xls;Extended Properties=ImportMixedTypes=Text;Excel 8.0;HDR=Yes;IMEX=1;”;

//You must use the $ after the object you reference in the spreadsheet
OleDbDataAdapter adap = new OleDbDataAdapter(“SELECT * FROM [Sheet1$]“, connStr);

DataSet ds = new DataSet();
adap.Fill(ds, “Courier”);
dataGridView1.DataSource = ds.Tables["Courier"].DefaultView;

}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}

Explanation of the above code:
Here I used OleDb to read the excel file. The excel file resides with exe file as Courier.xls.

Sheet1$ is the name of excel sheet.
Courier is the name of file so i am using the same name in filling the DataSet.

Now at last the data is filled into dataGridView.

Now if you are not able to read the integer value or any value other then text then
include the
Extended Properties=ImportMixedTypes=Text;Excel 8.0;HDR=Yes;IMEX=1 property in connection string.

The above code can also be used in a web application, for this you need to replace the Application.StartupPath with Server.MapPath

HaPpY CoDiNg………..

Posted in Excel, Widows Applications Tagged: C#, Excel, Widows Applications

URL rewriting using Global.asax, Error: The resource cannot be found.

dotnetcoderoom — Tue, 23 Jun 2009 10:30:58 +0000

Today I implemented my first application having URL rewriting enabled.
The application is created in Asp.net, C# and MS Sql 2005.

The url rewriting logic was working on the my localhost but it didn’t worked on production server.

I was getting an error: The resource cannot be found. while accessing the newly created URL pages.

I searched on Google about this and read lot, but nothing worked.

Finally I re-published the website and again uploaded all the files to production server and now everything worked like magic. Here is the URL: http://theplayclan.com/blog

Somewhere I read to check the permissions on server’s IIS, this method is explained below:

1) Open IIS manager.
2) Right click on your website’s virtual directory, select Properties.
3) Now, click on Configuration (in front of execute permissions option).
4) In the new popped-up window a list comes up as Application Extensions.
5) select .aspx option and click on edit.
6) Make sure that the Verify That File Exists is unchecked. This option explicitly check for the existence of file.
7) Save the settings and try again.

Somewhere it was mention to remove the *.* and regular expression extension mappings from the IIS may also work. The procedure of this is mentioned above.

Posted in Asp.Net, IIS, URL rewriting Tagged: Asp.Net, IIS, URL rewriting

Traverse / Loop through all form controls in asp.net

dotnetcoderoom — Sat, 07 Mar 2009 06:42:31 +0000

This post explains that how to traverse (loop through) all form controls in asp.net page.

foreach (System.Web.UI.Control ctrl in this.form1.Controls)
{
//here your code
}

Further if you want to get the state or data or manipulate the control, use the below code:
Here I am checking that at least one DropDownList item is selected out of all DropDownLists in the current webform.

bool isSelected = false;


foreach (System.Web.UI.Control ctrl in this.form1.Controls)

{
      if (ctrl.GetType() == typeof(System.Web.UI.WebControls.DropDownList))

      {

            DropDownList ddl = (DropDownList)ctrl;
            if (ddl.SelectedItem.Text != "")

            {

                  isSelected = true;

                  break;

            }

      }
}

if (isSelected == true) { Response.Write("selected"); } else { Response.Write("none selected"); }

Posted in Asp.Net, Asp.Net Controls, C# Tagged: Asp.Net, Asp.Net Controls, C#

Access your Asp.Net application over LAN

dotnetcoderoom — Fri, 09 Jan 2009 13:02:18 +0000

This post explains how to access some Asp.Net Application residing on another machine on network.

First of all you computer must be in the same workgroup as of the target computer. Then enter the following URL in the internet browser:

http://192.168.1.84/myWebsiteTest/default.aspx

http://ajay/myWebsiteTest/default.aspx

Here instead of ajay/192.168.1.84 you have to enter either the IP Address or the name of the computer on which asp.net application resides.

Just hit the enter key and you will see the output.

Happy Programing……..

Posted in Asp.Net Tagged: Asp.Net

MyBase in VB.Net is equal to base in C#

dotnetcoderoom — Fri, 09 Jan 2009 10:12:51 +0000

The Mybase object of VB.Net is similar to the base in C#.

So while using C# use “base” instead of “MyBase”.

Happy Programing……

Posted in Asp.Net Tagged: Asp.Net

Microsoft SQL Server DTS (Data Transformation Services) Import/Export Wizard Error

dotnetcoderoom — Sat, 15 Nov 2008 13:45:11 +0000

If you are facing problems in “Choose a destination” option while importing and exporting data using Microsoft SQL Server DTS (Data Transformation Services) Import/Export Wizard, specifically the error mentioned below then this post may be helpful for you to get it solved.

Error:
DTS Import/Export Error
Error Source: Microsoft OLD DB Provider for SQL Server
Error Description: [DBNETLIB][ConnectionOpen(Connect()).]SQL Server does not exist or access denied

Cause:
Inappropriate database drivers.

Solution:
In the Data Source combo-box
Select Microsoft ODBC Driver For SQL server
instead of
Microsoft OLE DB Provider For SQL server

Posted in Asp.Net Tagged: MS SQL Databae

Unable to validate data, ASP.net error

dotnetcoderoom — Fri, 07 Nov 2008 06:52:42 +0000

Error:
Unable to validate data, ASP.net error at System.Web.Configuration.MachineKeySection.GetDecodedData(Byte[] buf, Byte[] modifier, Int32 start, Int32 length, Int32& dataLength) at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString)

Information:
This is an View state decoding error.

Cause:
The basic reason of this is the difference of key while encrypting and decrypting the viewstate data. Suppose an asp.net rendered a page with key1 and saved the page state in view state, meanwhile asp.net’s key is changed to key2, now when some server side event will occur on page the viewstate will get decrypted and this error will occur as the old view state is now not valid due to a different encryption key.

It may occur when you open a page for along time and after that do some events on that.

Solution
Fix the key in your web.config file, so that only one key is used to encrypt and decrypt the viewstate data.

For more information visit:

http://www.experts-exchange.com/Programming/Programming_Languages/Dot_Net/ASP_DOT_NET/Q_21321364.html

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q312906

Posted in Asp.net Errors Tagged: Asp.Net, Asp.net Errors

Username Regex Validation

dotnetcoderoom — Wed, 15 Oct 2008 13:26:07 +0000

While accepting values from user you must validate the values because wrong values (like XSS attacks) can cause harm to your database and website.

Regex Code:
The Regular Expression below validates the username format.
^[a-zA-Z0-9_]{5,20}$

Scope:
So while creating a new user for a website you can validate the username string with the following business logic:
1) User name must be between 5 to 20 characters.
2) User name can have lowercase and uppercase characters.
3) User name can be alpha-numeric.
4) No special character allowed.

As you can see this is a very basic code to evaluate simple username for your website.
Implementation:

Asp.net HTML code:

Asp.net Code Behind:

using System.Text.RegularExpressions;

protected void btnValidate_Click(object sender, EventArgs e)
{
    if (Regex.IsMatch(txtRegex.Text, @”^[a-zA-Z0-9_]{3,16}$”) == true)
    {
        lblResultRegex.Text = “username ok”;
    }
    else
    {
        lblResultRegex.Text = “username invalid”;
    }
}

Now just run the application an verify the results.

To download a visual studio source code visit http://dotnetcoderoom.blogspot.com/2008/10/username-regex-validation.html

Posted in Asp.Net, C#, Regex Tagged: Asp.Net, C#, Regex

Read & Write to System Registry data, keys using C#

dotnetcoderoom — Fri, 10 Oct 2008 13:05:49 +0000

In this post i am going to explain that how to access the System Registry and how to read and write data to registry.

Step 1: First you need to import the below namespaces:
using Microsoft.Win32;

Step 2: Now create an object of Registry class:
RegistryKey regkey;

Step 3: Now access the registry and get the value of a key

regkey = Registry.CurrentUser.CreateSubKey(@”Software\Microsoft\FTP”);

if (regkey.GetValue(“Use PASV”) == null)
{
txtValue.Text = “No Value Specified”;
}

else
{
txtValue.Text = regkey.GetValue(“Use PASV”).ToString();
}

The above code gets the value of the “Use PASV” key from the
Registry\CurrentUser\Software\Microsoft\FTP path.

Step 4: Set the key value
regkey.SetValue(“Use PASV”, txtValue.Text);

Posted in C#, Microsoft Visual Studio .Net, Registry Tagged: C#, Microsoft Visual Studio .Net, Registry

Website Design Guidelines for beginners

dotnetcoderoom — Tue, 07 Oct 2008 09:55:39 +0000

This post describes some basis points of website design for beginners.

Before start designing of a website keep the below points in mind.

1) Keep the raw file (e.g. psd, ai, cdr) in RGB format. Create the site design with the original dimensions (e.g. for 800×600=780, for 1024, 768=970).

2) Try to keep text and images separate. Avoid overlapping of separate elements.

3) Keep text content more than image.

4) Always use web fonts like: Arial, Helvetica, Times New Roman, Courier New / Courier so that design at execution won’t look different from raw file.

5) Put some textual content and links in bottom of every page (e.g. copyright, sitemap, ).

6) Usage of Headings is also good practice.

7) Avoid using lot of graphics or images that are hard to load, instead use a thumbnail to show and a new page (or popup) to view full image.

8) Headline plays a significant role in attracting customers. Hence use catchy phrases for the headline, it’ll work well.

9) The most important is the content. Relevant content is the best way to keep the visitors hooked up and more over buy what you are selling. Correct use of words and sentences not only attracts the prospects but also helps the search engines to crawl it easily. Proper content, with relevant use of keywords is a MUST.

10) Determine the site navigation and its appearance before start designing. Also keep in mind we must use text as navigation, in case text is not possible images can be used but they must be small in size(kb), so that it wont take time to load.(Refer to yahoo home page).

11) User must should know where currently in site he is, show this by a textual bar like YOU ARE HERE

12) Avoid using gradient images in html page background, because it conflicts with site content and images at different screen resolutions.

13) Determine html link style (mouse over, normal) color and size.

Posted in CSS, Html Tagged: CSS, Html

How to get user’s IP address using asp.net

dotnetcoderoom — Fri, 03 Oct 2008 10:53:46 +0000

Many times we need to get the current user’s / visitor’s Ip address.

Sometimes this is essential for security reasons.
We must leg the user’s IP address in the following situations:

1) where you accept data from user, like guestbook newsletter, search page etc. This gives a plus point to the security of website, as you can get the user’s identity by his IP if he do something wrong with your website.

2) User login pages. Alwayskeep record the logins of website users. Record the datetime and IP of user.

If you want to blok some particular users to use your website then on page load just ckeck the current Ip against database of ip’s you have created for blacklisting.
Now coming to the point,
How to get user’s IP address using asp.net

HttpContext.Current.Request.UserHostAddress;
or
HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

The above code may return the IP with proxy.

Use the below code to get the IP address of the machine and not the proxy use the following code
HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

Posted in Asp.Net Tagged: Asp.Net

Preload images in HTML using JavaScript

dotnetcoderoom — Mon, 29 Sep 2008 11:59:52 +0000

Preloading means loading an object (graphics, text, movie) before showing it to output.

A good example is of preloading in flash files, when you see a loader before displaying the content, and after loading site shows a smooth experience of flow of data.

This is mostly used when there is an mouser over images to be loaded. If user mouse overs an image and then you loads the new mouse-over image it may take a few seconds to load, which leads to a small blank image over the image area. By pre-loading the image you can show mouseover image instantly without any delay.

In this post I am explaining how to do preaload imags in HTML using JavaScript, without using flash.

We have to use the Head tag of html as this is the one which loads on first page executiution.

The above code lods two images naming productSmall.gif and storeSmall.gif respictively from images directory. It creates a new object of image and assigns it a dimention and a file to load.

The document.imags condition has been used to determine that the browser supports the images or not.

Posted in Html, JavaScript Tagged: Html, JavaScript

Using RequiredFieldValidator with DropdownList Asp.Net

dotnetcoderoom — Mon, 29 Sep 2008 09:18:00 +0000

You may have used RequiredFieldValidator with Text controls, but if you wnat to use it with DropDownList controls, you need to do some little extra work. Here is the trick.

Step 1: Create an DropDownList

Step 2: Drag and RequiredFieldValidator. Set it’s ControlToValidate property to the DropDownLis’s object.

Step 3: Fill some items in the DropDownList. Add a first item as “Select”. This will indicate the user that he should select an option.

Step 4: Now set the RequiredFieldValidator’s “InitialValue” property to “Select”.

Now all of your code should look like this :

Select
India
USA
Canada

Now you are all set to go and test it.

To read complete post and source code please visit dotnetcoderoom.blogspot.com

Posted in Asp.Net Tagged: Asp.Net, Asp.Net Controls, Validation Controls

Change MS SQL 2005 login password using sql query

dotnetcoderoom — Wed, 24 Sep 2008 10:55:17 +0000

If you want to change the MS Sql 2005 ‘s password then just run the following sql query after logging into query anlyzer

sp_password ‘oldPassword’ , newPassword’

Note
Always use strong SQL passwords (i.e. having uppercase characters , lowercase characters, numeric values, special characters) for security purpose, this way it will be difficult to hack, hard to guess, hard to crack by brute force attacks.

Posted in DataBase, MS SQL Tagged: DataBase, MS SQL

Show line breakes in Asp.net Label

dotnetcoderoom — Wed, 17 Sep 2008 10:20:20 +0000

To show line breakes in a server side asp.net label, you can either use a HTML formatted text or a plain text.

HTML formatted text contains “
” tags so while rendring the control .net framework handles the task to show the proper html formatted text into a Label.

Example:
lblDescription.Text=”name
description”;
The above code will display a line gap between name and description.
But in case if user inputted data using a non-html enabled textbox then it is a point of problem.

While displaying data, inputted by simple multiline textbox, line breaks looses its state and when the data displayed on a label it looks like a simple constant text line. Interestingly if you try to show the same data back in a textbox it will look nice with proper line breaks. But we can’t use textbox every where because of designing requirements.

To keep the line breaks you must convert the html new line special indicator to HTML break “
” tag.

Solution:
lblDescription.Text = txtInput.Text.ToString().Replace(Environment.NewLine, “
”);

The above code replaces the “NewLine” indications to “
” at run time, and displays the data same as input formatting.

For demo source code visit
http://dotnetcoderoom.blogspot.com/2008/09/show-line-breakes-in-aspnet-label.html

What is RSS feed

dotnetcoderoom — Thu, 11 Sep 2008 11:29:51 +0000

Really Simple Syndication (RSS) feeds are XML files which are provided by websites so you can view their contents on other website rather than browsing their site. Basically it’s an information sharing process having some specified
content format of text and related links.

Example:

I have a blog and you want to show the my Blog’s content on your website.
So what i have to do is to create a RSS of my blog content and give RSS generation page link to you.
The RSS page will generate an XML based on content I want to write in the file.

You have to consume that XML into your website and show the content.

These days nearly all blog websites provides their own RSS consuming applications, so you don’t have to bother about it if you are using a public web portal like orkut, WordPress, Blogspot etc.

Wait for a new post for reading and writing RSS applications.

Operator + cannot be applied to operands of type string and method group, C# error

dotnetcoderoom — Mon, 08 Sep 2008 17:48:17 +0000

Cause

This error comes up when you tries to append two strings with the “+” sign. As the + sign in C# is a arithmetical operator so you cannot use this too append two string type values. To use “+” the values or variables must be if numeric type.

As C# uses doesn’t supports implicit typecasting, for string concatenation use “&” sign.
Example

string varTest = “”;
string str1 = “abc”;
int str2=21;

varTest = str1 + str2;

The above stqatmet will cause in error stating “Operator + cannot be applied to operands of type string and method group“. Because we are trying to add a string variable in a numeric variable.

To remove the error you must convert all the numeric (integer) datatype or variables to string.

varTest = str1 & str2.ToString();

The output of the above code will be abc21

Conclusion
We must convert all values to a uniform datatype before storing them into a variable.

Send e-mail in ASp.Net 2.0 and onwards in C#

dotnetcoderoom — Sat, 06 Sep 2008 10:25:30 +0000

The following code example can be used to send email using Asp.Net in 2.0 and higher versions version.

The Namespace of email class is changed to System.Net.Mail from System.Web.Mail.

Import the System.Net.Mail Namespace
using System.Net.Mail;

Code:

MailMessage mail = new MailMessage();
mail.From = new MailAddress(“info@yourDomain.com”,”Alert”);
mail.To.Add(“you@yourdomain.com”);
mail.Subject = “mail test”;
mail.IsBodyHtml = true;
mail.Body = “Your message here”;
SmtpClient smtp = new SmtpClient(“mail.yourdomain.com”);
smtp.Credentials = new System.Net.NetworkCredential(“info@yourdomain.com”,”password of this info”);
smtp.Send(mail);

Note:
The email address specified in the “FROM” field must be valid and it need to be of your domain.
In the SmtpServer the domain name must be same as of your domain on which website is hosted.

For complete source code visit
http://dotnetcoderoom.blogspot.com

Send e-mail using Asp.Net 1.1

dotnetcoderoom — Sat, 06 Sep 2008 10:10:11 +0000

The following code example can be used to send email using Asp.Net in 1.1 version.

First import Web.Mail namespace.
using System.Web.Mail;

Now add this code to your button click event:

MailMessage mail = new MailMessage();

String msgText = string.Empty;
msgText = “Message here, you can also use Html tags for Rich Text Formatting.
Hi.”;

mail.To = “you@yourdomain.com”;
mail.CC = “anyEmailAddress, its optional”;
mail.Bcc = “anyEmailAddress, its optional”;
mail.From = @”"”Ajay”" ”;
//mail.From = “info@yourdomain.com”;
mail.Subject = “Mail test”;
mail.BodyFormat = MailFormat.Html;
mail.Body = msgText;
SmtpMail.SmtpServer = “mail.yourdomain.com”;

SmtpMail.Send(mail);

Note:

The email address specified in the “FROM” field must be valid and it need to be of your domain.
In the SmtpServer the domain name must be same as of your domain on which website is hosted.

Google’s Web Browser called Google Chrome is launched

dotnetcoderoom — Thu, 04 Sep 2008 06:08:59 +0000

Yapee.

Google has launched it’s own web browser named Google Chrome.
Google Chrome is a very simple and sophisticated browser and very easy yo use.

Google Chrome Features:
~ Multiple tabs can be opened in same instance window.
~ Thumbnails of most visited pages.
~ Automatic bookmarks and history search reaults when you type any URL.
~ Import settings and bookmarks from other web browsers.
~ Application shortcuts
~ Dynamic tabs
~ Crash control
~ Incognito mode
~ Safe browsing
~ Instant bookmarks
~ Simpler downloads

For more features visit http://www.google.com/chrome/intl/en-GB/features.html

So go and give a try to Google Chrome.

Download Google Chrome here http://www.google.com/chrome/

Rename a table Column in MS SQL

dotnetcoderoom — Tue, 02 Sep 2008 05:37:15 +0000

How to rename a MS SQL server database table column name after the table creation??
You can rename a column regardless of it is null or contains any data.

We need to use a System stored procedure to rename. Any command with alter keywords won’t work.

Code
EXEC sp_rename ‘tableName.[oldColumnName]‘, ‘newColumnName’, ‘COLUMN’

Example:
EXEC sp_rename ‘Ultra_tblPressRelease.[uShowStatus]‘, ‘uShowInA2B’, ‘COLUMN’

The above line will rename the existing column named uShowStatus of table tblPressRelease to uShowInA2B.

There will be no adverse effect of this procedure on your table data.
But you have to update all your SQL Cursors and Stored Procedures with the new column name (if any).

ASp.Net 2.0 GridView Delete Button Confirmation pop-up

dotnetcoderoom — Sat, 30 Aug 2008 07:34:40 +0000

While using GridView in asp.net pages wants to confirm the deletion form user. To do this we can take him to another page having GUI to confirm and then delete the record on that page.

Instead of doing so much hardwork you can achieve this on the same page with a little bit of extra code.

Workaround

Add a client alert script to the delete button of every row.
In the delete event of GridView delete the record.

Code

==================================================
Page’s Aspx Design File Begins
==================================================
ForeColor=”#333333″ GridLines=”None” OnRowDataBound=”gvFaq_RowDataBound” OnRowDeleting=”gvFaq_RowDeleting”>

==================================================
Page’s Aspx Design File Ends
==================================================

Database Design FIle

==================================================
Code Behind File Begins
==================================================
1) Import Namespaces
using System.Data.SqlClient;

2) Declare global variables which will be used in page
DataSet ds = new DataSet();
SqlDataAdapter da;
SqlConnection myConnection;
String connStr = “your database connection string goes here”‘;
String sql = string.Empty;

3) Page Load event
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack == false)
{
fillGridView();
}
}

4) GridView filling method
private void fillGridView()
{

try
{
myConnection = new SqlConnection(connStr);
sql = “select * from tblFaq order by slno desc”;

da = new SqlDataAdapter(sql, myConnection);
ds.Clear();
da.Fill(ds, “tblFaq”);

gvFaq.DataSource = ds.Tables[0];
Page.DataBind();

}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}

5) In the RowDataBound event add a java script event to the delete cell.
protected void gvFaq_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
e.Row.Cells[4].Attributes.Add(“onClick”, “return confirm(‘Are you sure you want to delete the record?’);”);
}
}

6) Handle the RowDeleting event to delete the record of current row.

protected void gvFaq_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
try
{
myConnection = new SqlConnection(connStr);
myConnection.Open();
sql = “delete from tblFaq where slno = ” + Convert.ToInt32(gvFaq.Rows[e.RowIndex].Cells[0].Text);
SqlCommand oldcom = new SqlCommand(sql, myConnection);
oldcom.ExecuteNonQuery();
myConnection.Close();
fillGridView();
Response.Write(“Record Deleted”);
}
catch (Exception ex)
{
lblError.Text = ex.Message;
}
}

==================================================
Code Behind File Ends
==================================================
The output will look like this

For Source Code visit http://dotnetcoderoom.blogspot.com/2008/08/aspnet-20-gridview-delete-button.html

Show Message Box in Asp.net

dotnetcoderoom — Mon, 25 Aug 2008 10:23:58 +0000

It’s not possible to show an alert message box in asp.net using server side code (like vb.net windows apps, msgbox).

But this can be achieved by generating a client side Java Script code in a server-side event.

Code

Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
showMsg(“hey there”, Me)
End Sub

Public Sub showMsg(ByVal sMsg As String, ByVal frm As Web.UI.Page)

Dim sb As New System.Text.StringBuilder
Dim oFormObject As System.Web.UI.Control

sMsg = sMsg.Replace(“‘”, “\’”)
sMsg = sMsg.Replace(Chr(34), “\” & Chr(34))
sMsg = sMsg.Replace(vbCrLf, “\n”)
sMsg = “”

sb = New System.Text.StringBuilder
sb.Append(sMsg)

For Each oFormObject In frm.Controls
If TypeOf oFormObject Is HtmlForm Then
Exit For
End If
Next
oFormObject.Controls.AddAt(oFormObject.Controls.Count, New LiteralControl(sb.ToString()))
End Sub

Explanation:

On the button click event i write a JavaScript method to the page, the JavaScript method is displaying the message your pass to the method showMsg().

Note:
Please don’t pass special characters as the message, as they will conflict with the special characters of JavaScript and message won’t come properly.

For more articles updates and sourcecodes please visit dotnetcoderoom

Remove yellow autocomplete textbox background caused by Google Toolbar in Internet Explorer

dotnetcoderoom — Mon, 25 Aug 2008 07:12:38 +0000

Hey guys,

Recently i ran into this problem, some users of my client’s website complaint that in some web forms the name and email fields comes have a yellow background which hinders the readability of the field.

After getting into depth details of the problem I came to knew that it happens only in Internet Explorer having Google Toolbar installed. In Firefox, Opera, Netscape it works fine.

This is a feature of Google Toolbar that it automatically highlights the fields (e.g. name, email etc.) in the yellow background color which facilitate the user to autocomplete the specified field.

Using some server-side and client side tweaks you can restrict the field to become autocomplete but Google Toolbar will still show the yellow background. The Google Toolbar feature overrides nearly all the server-side as well as client-side tweaks for the Name and Email fields.

Workaround:

To avoid the field’s autocomplete:

You can set the AutoCompleteType property in the Html tag of Textbox like:

Some enumerations for the AutoCompleteType property are :

BusinessCity – City in the business category

BusinessCountryRegion – Country/region in the business category

BusinessFax – Fax number in the business category

BusinessPhone – Phone number in the business category

BusinessState – State in the business category

BusinessStreetAddress – Street address in the business category

BusinessUrl – Web site URL in the business category

BusinessZipCode – ZIP code in the business category

Cellular – Phone number in the mobile-phone category

Company – Business name in the business category

Department – Department in the business category

Disabled – AutoComplete feature is disabled

DisplayName – Name to display in the user category

Email – E-mail in the user category

FirstName – First name in the user category

Gender – Gender in the user category

HomeCity – Home city in the user category

HomeCountryRegion – Home country/region in the user category

HomeFax – Fax number in the user category

Homepage – Web site URL in the user category

HomePhone – Phone number in the user category

HomeState – Home state in the user category

HomeStreetAddress – Home street in the user category

HomeZipCode – ZIP code in the user category

JobTitle – Job title in the user category

LastName – Last name in the user category

MiddleName – Middle name in the user category

None – No category specified

Notes – Extra information in the form

Office – Office location in the business category

Pager – Phone number in the pager category

Search – Keywords in the search category

Please note the difference between None and Disabled enumerations.

But setting the AutoCompleteType property will only direct browser to not to give options for autocomplete, it doesn’t removers yellow background.

Remove Yellow background

Any code used to set the background color of textbox will fail in following conditions (regardless of run time or design time):

a) Specifying BackColor

b) Specifying background-color in CSS or Style attribute.

The one and only perfect way to do is :

a) Specify a CSS class for the textbox, e.g.

.txtNameStyle

{

font-size:12px;

height:13px;

border-style:none;

background-color: #666666 !important;

color:#ffffff;

}

b) Now declare the text box control so that it looks like this :

Note:

The if the background is !important in Css-Style, the input is not considered by Google Toolbar. That’s all what we need.

Now the last step is to just test the page into Internet Explorer.

That’s all for this post, hope you will like it.
Please leave a comment for any help.

For more articles updates and sourcecodes please visit dotnetcoderoom

Update database data using SQL Cursors based on conditions

dotnetcoderoom — Fri, 22 Aug 2008 07:25:15 +0000

Recently one of my MSSQL database got SQL Injection attacks.
Hacker put some JavaScript code in all row data to get hits on his website (which is apparently blocked, and soon my site will also be got banned if it keep happening for a long time).

Because the database has a huge amount of data, i can’t update table data using ExecuteNonQuery commands as it will result in a great overload on database and network resources.

So I decided to make something logical which is fast and logical way to handle this situation, and at last i ended up with writing a cursor.

This cursor finds a specific string and replaces it with null.

Scenario:

Create a table with sample data

create table tblDataUpdateTest
(
slno int identity(1,1),
cName varchar(50),
cRemarks varchar(50),
)

insert into tblDataUpdateTest (cName, cRemarks) values (‘name1′,’some text here BADCODE’)
insert into tblDataUpdateTest (cName, cRemarks) values (‘name2′,’raBADCODEhul’)
insert into tblDataUpdateTest (cName, cRemarks) values (‘name3′,’dj BADCODEis devil’)

select * from tblDataUpdateTest

Create Cursor to update database table

Declare @@counter int
set @@counter=0
Declare @@slno int
Declare @@cRemarks varchar(100)

Declare tmepTbl cursor
For
Select slno,cRemarks from tblDataUpdateTest

Open tmepTbl /* Opening the cursor */

fetch next from tmepTbl
into @@slno,@@cRemarks

while @@fetch_Status-1
begin

Update tblDataUpdateTest
set cRemarks = Replace(@@cRemarks,’BADCODE’,”)
where slno = @@slno

fetch next from tmepTbl
into @@slno, @@cRemarks

set @@counter=@@counter+1
end
close tmepTbl
Deallocate tmepTbl

Conclusion:
By running this cursor all the occurrences of BADCODE will be eliminated from the specified table.

Note:
I used word BADCODE here but in my actual data it was a java script tag which was creating all the problem.

For more articles updates and sourcecodes please visit dotnetcoderoom

Change fore color of control using Java Script

dotnetcoderoom — Tue, 12 Aug 2008 06:14:30 +0000

Many times we need to set the fore color or back color of controls (e.g. label, button etc).

This can be achieved using CSS (supposing all of you know that) also but we can also do it using Java Script.

This is a simple java script trick so you can use it with html controls as well as asp.net server controls.

Here is an example for doing this :

Code:

onmouseout=”style.color=’#6D6E71′”>CONTACT

onmouseout=”style.backgroundcolor=’#6D6E71′”>CONTACT

In the above code example i set the value of style collection’s color property on the “onmouseover” event and reversed on “onmouseout” event
For more articles updates and sourcecodes please visit dotnetcoderoom

XML Serialization in .Net Framework (Write Xml from Dataset)

dotnetcoderoom — Tue, 05 Aug 2008 09:32:39 +0000

WHAT IS SERIALIZATION ?
Serialization is converting an object to a format in which it can be saved (exported) as file or a physical medium. A simple and basic example would be, if we create an XML from a Dataset it is called Serialization.

CODE:
try
{
DataSet ds = new DataSet();
SqlDataAdapter da;
SqlConnection myConnection;
String connStr = ConfigurationManager.ConnectionStrings["DatabaseConnectionString1"].ToString();

SqlConnection myConnection = new SqlConnection(connStr);
String sql = “select * from tblCategory”;
da = new SqlDataAdapter(sql, myConnection);
ds.Clear();
da.Fill(ds, “tblCategory”);
ds.WriteXml(Server.MapPath(“~/xmls/info.xml”));
}
catch (Exception ex)
{
Response.Write(ex.Message);
}

The above code will write an XML file called info.xml from a Dataset called “ds” into xmls folder in root of website.

Options
Alternatively we can use some advanced options to format the data which is being written.

ds.WriteXml(Server.MapPath(“~/xmls/info.xml”, XmlWriteMode.WriteSchema);

Some options are. Some of the attributes available in Microsoft .Net Framework are as follows:

♣ XmlWriteMode.DiffGram — Writes the entire DataSet as a DiffGram.
♣ XmlWriteMode.IgnoreSchema — Writes the current contents of the DataSet as XML data, without an XML Schema Definition language (XSD) schema.
♣ XmlWriteMode.WriteSchema — Writes the current contents of the DataSet as XML data with the relational structure as inline XSD schema.
For more articles updates and sourcecodes please visit dotnetcoderoom

Add meta tags dynamically to a page having a master page in Asp.Net

dotnetcoderoom — Tue, 05 Aug 2008 09:30:55 +0000

As a master page provides a common layout to all pages, and tag is included in the master page itself instead of content page. So one questing comes how to add different meta tags to all different pages (or dynamically generate meat tags) .

This post describes adding a meta tag in an dynamic page with dynamically generated content. This code can be used if you want to add meta tag to a page which is using Master pages.

Two approaches can be taken for this, one is using .net framework’s features, and second is by playing with “ContentPlaceHold”.

Approach 1 : Using .net framework’s features to add meta tags

Add the code below in page_load event of the content page.

Dim metaDescription As New HtmlMeta()
metaDescription.Name = “metaTagHeading (example: keywords, description)”
metaDescription.Content = “A description or content of meta tag here”
Me.Header.Controls.Add(metaDescription)

Approach 2 : Playing with “ContentPlaceHold”.

Step1

Put one content place holder in your master page in HEAD section, like::

Step2

Now in the content (child) page, put this code:

<%=pageTitle%>
”>
”>

Step3
In content page’s vb or cs file code:

Declare variables as below in the global declaration section (not in page load)

Protected pageTitle As String = “”
Protected varKeywords As String = “”
Protected varDescription As String = “”

Step4
Fill values in page_load event:

pageTitle = “Your Meta Tag “
varKeywords = “Your Meta Tag “
varDescription = “Your Meta Tag “

**End of article**

For more articles updates and sourcecodes please visit dotnetcoderoom

Disable the right click on a web page

dotnetcoderoom — Tue, 05 Aug 2008 09:28:22 +0000

Some website has right-click disabled so that user cant copy paste using mouse, or cant save images contained into webpage.

Copy paste this code

Html page content here

**End of article**

For more articles updates and sourcecodes please visit dotnetcoderoom

Rotate a Label Text

dotnetcoderoom — Tue, 05 Aug 2008 09:24:37 +0000

Display Vertically and horizontally rotated text in a server side label ASP.NET or in a HTML control

your text here

For more reference:

http://www.w3.org/TR/2001/WD-css3-text-20010517/

http://msdn.microsoft.com/en-us/library/ms531187.aspx
**End of article**

For more articles updates and sourcecodes please visit dotnetcoderoom

Read CSV into an Array

dotnetcoderoom — Tue, 05 Aug 2008 09:22:43 +0000

Many times we have .csv or .xls files and we need to insert data into database or manipulate it.

Dim reader As Microsoft.VisualBasic.FileIO.TextFieldParser
reader = My.Computer.FileSystem.OpenTextFieldParser _
(“C:\Temp\test.csv”)
reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
reader.Delimiters = New String() {“,”}
Dim currentRow As String()
While Not reader.EndOfData
Try
currentRow = reader.ReadFields()
Dim currentField As String
For Each currentField In currentRow
MsgBox(currentField)
Next
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MsgBox(“Line ” & ex.Message & _
“is not valid and will be skipped.”)
End Try
End While

**End of article**

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Update Dataset data back to Database

dotnetcoderoom — Tue, 05 Aug 2008 09:00:17 +0000

This post explains how to insert, update, and delete data in a Database using Dataset.

The DataSet can be considered an in-memory cache of data retrieved from a database. The DataSet consists of a collection of tables, relationships, and constraints.

Firstly, we have to fill data into a DataSet from Database.
Secondly, when the DataSet is loaded, you can modify the data, and the DataSet will keep track of the changes made bu user.

The Add method of DataTable accepts either an array of the expected data columns, or a DataRow.

(Please note that all code is in c# language)

Step 1: Create a new Connection and SqlDataAdapter
SqlConnection myConnection = new SqlConnection(“connectionStringGoesHere”);
SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter(“Select * from tblNews”, myConnection);
DataSet myDataSet = new DataSet();
DataRow myDataRow;

Step 2: Create SqlCommandBuilder(The SqlDataAdapter does not automatically generate the Transact-SQL statements required to match changes made to a DataSet with SQL Server. But, you can create a SqlCommandBuilder object to automatically generate Transact-SQL statements for single-table updates.)
SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);

// Set the MissingSchemaAction property to AddWithKey because Fill will not cause primary
// key & unique key information to be retrieved unless AddWithKey is specified.
mySqlDataAdapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;

mySqlDataAdapter.Fill(myDataSet, “tblNews”);

Step 3: Add rows to DataTable

myDataRow = myDataSet.Tables["tblNews"].NewRow();
myDataRow["cNewsId"] = “NewID”;
myDataRow["cHeading"] = “New Heading”;
myDataRow["cContent"] = “Content here”;

myDataSet.Tables["tblNews"].Rows.Add(myDataRow);

Step 4: Editing Row Data
We can change the data in a DataRow by accessing the DataRow. Use the index of the row in the RowsCollection accessed through the Rows property:

myDataSet.Tables["tblNews"].Rows[0]["cHeading"]=”Abc”;

Access a specific row by specifying the Primary Key value:

DataRow myDataRow1 = myDataSet.Tables["tblNews"].Rows.Find(“124″);
myDataRow1["cHeading"]=”Abc”;

Here “124″ is the value of the Primary Key “cHeading” in the “tblNews” table.

Step 5: Deleting a record
Use Delete method to delete a Row. All changes are done in dataset until you don’t explicitly update DataSet data to the Database. Use RejectChanges method of DataSet to reverse all changes made to DataSet.

myDataSet.Tables["tblNews"].Rows[0].Delete();

Note: The original and new values are maintained in the row. The RowChanging event allows you to access both original and new values to decide whether you want the edit to proceed.

SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);

Step 6: Finally Update DataBase
To submit the data from the DataSet into the database, use dataAdapter’s Update method.

mySqlDataAdapter.Update(myDataSet, “tblNews”);

A Visual Studio Solution code sample will be coming soon……

**End of article**

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Show default Text in Email TextField

dotnetcoderoom — Tue, 05 Aug 2008 08:56:37 +0000

Show default Text in Email Field.
Like on form load show “enter email id” in email field.
On click clear this text.
on mouse out with nothing entered show again this into textbox.

Code:

**End of article**

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