Saturday, August 30, 2008

ASp.Net 2.0 GridView Delete Button Confirmation pop-up

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.

Download Source Code here

Code

==================================================
Page's Aspx Design File Begins
==================================================
<asp:GridView ID="gvFaq" runat="server" AutoGenerateColumns="False" CellPadding="4"
ForeColor="#333333" GridLines="None" OnRowDataBound="gvFaq_RowDataBound" OnRowDeleting="gvFaq_RowDeleting">
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<Columns>
<asp:BoundField DataField="slno" HeaderText="Sl No." />
<asp:BoundField DataField="cHeading" HeaderText="Question" />
<asp:BoundField DataField="cPosition" HeaderText="Position" />
<asp:CommandField HeaderText="Manage" ShowSelectButton="True" />
<asp:CommandField HeaderText="Delete" ShowDeleteButton="True" />
</Columns>
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<EditRowStyle BackColor="#999999" />
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
</asp:GridView>
==================================================
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


javascript:void(0)







Download Source Code here

Monday, August 25, 2008

Show Message Box in Asp.net

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.

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

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:

<asp:TextBox ID=”txtemail” runat=”server” AutoCompleteType=”Disabled” Width=”219px”></asp:TextBox>

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 :

<asp:TextBox ID=”txtName” runat=”server” CssClass=”txtNameStyle” Width=”219px”></asp:TextBox>

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.

BYE

Friday, August 22, 2008

Update database data using SQL Cursors based on conditions

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.


Tuesday, August 12, 2008

Change fore color of control using Java Script

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:

<a href=”contact.aspx” class=”mainMenuNormalStyle” onmouseover=”style.color=’#FFB537′;”

onmouseout=”style.color=’#6D6E71′”>CONTACT</a>
<a href=”contact.aspx” class=”mainMenuNormalStyle” onmouseover=”style.backgroundcolor=’#FFB537′;”

onmouseout=”style.backgroundcolor=’#6D6E71′”>CONTACT</a>
In the above code example i set the value of style collection’s color property on the “onmouseover” event and reversed on “onmouseout” event.