Sqldatasource control set dynamic Connectionstring in .aspx page only


Set Dynamic ConnectionString to SqlDataSource ASP.NET Control Inside GridView Template

Intro: The SqlDataSource control enables you to use a Web server control to access data that is located in a relational database. You can use the SqlDataSource control with data-bound controls such as the GridView, FormView, and DetailsView controls to display and manipulate data on an ASP.NET Web page, using little or no code.

Here in this article, I am writing how to set Dynamically ConnectionString Attribute on  SqlDataSource ASP.NET Control. Setting connection string for SqlDataSource control can de done programmatically in the code-behind ie (.aspx.cs) file.  

On Page_Load:

SqlDataSource1.ConnectionString = yourconnectionstring;

If the SqlDataSource control is inside the FooterTemplate of a GridView control then it will not be accessible at Page_Load. Here's the challenging task of how to set ConnectionString on SqlDatasource control under Gridview Templates. By following the below steps you can achieve this:

Step 1: Here sample code of Gridview templates:

   <asp:dropdownlist autopostback="True" datasourceid="sqldsWorkcategory" datatextfield="name_wt" datavaluefield="id_wt" id="cmbfWorkCategory" onselectedindexchanged="cmbfWorkCategory_SelectedIndexChanged" runat="server" width="118"> </asp:dropdownlist>
   <asp:sqldatasource connectionstring="<%$ RepConnectionString: " getconnection="getconnection">" id="sqldsWorkcategory" runat="server" selectcommand="SELECT [id_wt], [name_wt] FROM [yourtablename]"> </asp:sqldatasource>

Step 2: Now edit your web.config file As I have many connections so have to make a different XML file to store all connections key

<configsource onstring.xml="onstring.xml" pp_data="pp_data">
   <!-- Now Add this pieace of code under Compilation as u can see. --> 
   <compilation debug="true" targetFramework="4.0">
      <add expressionprefix="RepConnectionString" type="RepConnectionStringExpressionBuilder"> </add>

Step 3: Add class file inside App_code. Have named as CodeExpressionBuilder.cs.
Note: using System.CodeDom; is needed if u find an error then add a reference or google for this namespace,

Code of CodeExpressionBuilder.cs just copy as it is.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Compilation;
using System.Configuration;
using System.IO;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;
using System.Collections.Generic;
using System.Xml.Linq;
using System.Xml;
using System.CodeDom;

//this is what we set in .aspx page (ie sqldatacource control)
public class RepConnectionStringExpressionBuilder : ExpressionBuilder

public override CodeExpression GetCodeExpression(BoundPropertyEntry entry, object parsedData, ExpressionBuilderContext context)
 CodeTypeReferenceExpression thisType = new CodeTypeReferenceExpression(base.GetType());
 CodePrimitiveExpression expression = new CodePrimitiveExpression(entry.Expression.Trim().ToString());
 string evaluationMethod = "GetConnectionString"; //
 return new CodeMethodInvokeExpression(thisType, evaluationMethod, new CodeExpression[] { expression });
public static string GetConnectionString(string expression)
 string getcon1='Some thing lke ur connectionstring... form xml'
 SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings[getcon1].ConnectionString);
 string wConnString = conn.ConnectionString;
 return wConnString;

This will set your dynamic ConnectionString for SqlDataCource control on .aspx page.

Thank you for reading, pls keep visiting this blog and share this in your network. Also, I would love to hear your opinions down in the comments.

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  1. Anonymous 05/21/2012 09:50:35
    Works like a charm, thanks!
  2. Satinder singh 05/30/2012 19:58:28
    My pleasure...
    If its helps anyone