A simple RadioButtonList in a Web DataGrid Column

• Download source files - 2.15 Kb
• Download demo project - 16 Kb

Introduction

This article exposes, in a very simple and practical way, how a single RadioButton acts as a RadioButtonList in a web DataGrid server control column. It�s nothing about two thousand lines of code, nor custom control, neither signed assembly. I always wonder why do complicated when we can do simple.

Solution

First, in the ItemCreated DataGrid event, I�ll wire the RadioButton CheckedChanged event:

private void DataGrid1_ItemCreated(object sender, 
   System.Web.UI.WebControls.DataGridItemEventArgs e)
{
   //Find the RadioButton control

   RadioButton oRb = ((RadioButton)e.Item.FindControl("rb"));             
   if(oRb != null)
   {                    
      //Wire the RadioButton's event

      oRb.CheckedChanged += new
         System.EventHandler(this.rb_CheckedChanged);
   }
}

Second, in the RadioButton CheckedChanged event, I�ll loop through DataGrid items to find the previous and current radio buttons and, if found, the previously checked button will be unchecked:

private void rb_CheckedChanged(object sender, System.EventArgs e)
{
   //Find the current selected RadioButton

   RadioButton oRb1 = (RadioButton)sender;

   foreach(DataGridItem oItem in DataGrid1.Items)
   {                
      //Find the previous selected RadioButton

      RadioButton oRb2 = (RadioButton)oItem.FindControl("rb");

      //Display info for the current selected button

      if( oRb2.Equals(oRb1) )
      {                    
         Message.Text = 
            String.Format("Selected Id is: {0}, 
                         and the Description is:{1}",
                         ((Label)oItem.FindControl("lblId")).Text,
                         ((Label)oItem.FindControl("lblDesc")).Text);
      }
       //Uncheck previously selected button

       else 
          oRb2.Checked = false;
   }
}

The info is displayed in a message label after I�ve recuperated the lblId and lblDesc text from the HTML web form, like in the code below:

<asp:label id="Message" Runat="server"></asp:label>
...
<Columns>
   <asp:TemplateColumn HeaderText="Id">
      <ItemTemplate>
         <asp:Label id="lblId" runat="server" Text='<%# 
            DataBinder.Eval(Container.DataItem, "Id") %>' />
      </ItemTemplate>
   </asp:TemplateColumn>

   <asp:TemplateColumn HeaderText="Description">
      <ItemTemplate>
         <asp:Label id="lblDesc" runat="server" Text='<%# 
            DataBinder.Eval(Container.DataItem,"Description") %>' />
      </ItemTemplate>
   </asp:TemplateColumn>
... 
</Columns>
...

The DataGrid is bound to an ArrayList aList in the BindDataGrid():

private void BindDataGrid()
{
   ArrayList aList = new ArrayList();
      
   for(int i=1; i<6; i++)
   {
      aList.Add(new ItemInfo(i, "Desc " + i.ToString()));
   } 

   //Binding and displaying the info in the DataGrid

   DataGrid1.DataSource = aList;
   DataGrid1.DataBind();
}

For more details, please download the source code above. You have nothing else to do than to create a new C# project for an ASP.NET application and add the source code files. That�s all about it.

Enjoy!