C# – Assign an event to a custom control inside a Repeater control

asp.netc

I have a Repeater control which in some of its cells contains a UserControl which contains a DropDownList. On the ItemDataBound event of the Repeater control I'm assigning an event to the DropDownList like so:

protected void MyRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)  
{  
...  
MyControl myControl = (MyControl)e.Item.FindControl("MyControl01");  
myControl.DataSource = myObject;  
myControl.DataBind();  
myControl.DropDownList.SelectedItemChange += MyMethod_SelectedIndexChanged;  
myControl.DropDownList.AutoPostBack = true;  
....  
}  

protected void MyMethod_SelectedIndexChanged(object sender, EventArgs e)  
{  
//Do something.  
}

The event never fires. Please I need help.

Best Answer

Your event is not being raised in a PostBack because your event handler has not been attached (it is only attached during the iteration of the page life-cycle when your repeater is databound).

If you attach your event handler declaratively in the markup such as:

<asp:Repeater ID="Repeater1" runat="server">
     <ItemTemplate>
         <asp:DropDownList ID="DropDownList1" runat="server" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" />
    </ItemTemplate>
</asp:Repeater>

Then your event handler will be called during PostBacks.

Related Solutions

C# – Should ‘using’ directives be inside or outside the namespace

There is actually a (subtle) difference between the two. Imagine you have the following code in File1.cs:

// File1.cs
using System;
namespace Outer.Inner
{
    class Foo
    {
        static void Bar()
        {
            double d = Math.PI;
        }
    }
}

Now imagine that someone adds another file (File2.cs) to the project that looks like this:

// File2.cs
namespace Outer
{
    class Math
    {
    }
}

The compiler searches Outer before looking at those using directives outside the namespace, so it finds Outer.Math instead of System.Math. Unfortunately (or perhaps fortunately?), Outer.Math has no PI member, so File1 is now broken.

This changes if you put the using inside your namespace declaration, as follows:

// File1b.cs
namespace Outer.Inner
{
    using System;
    class Foo
    {
        static void Bar()
        {
            double d = Math.PI;
        }
    }
}

Now the compiler searches System before searching Outer, finds System.Math, and all is well.

Some would argue that Math might be a bad name for a user-defined class, since there's already one in System; the point here is just that there is a difference, and it affects the maintainability of your code.

It's also interesting to note what happens if Foo is in namespace Outer, rather than Outer.Inner. In that case, adding Outer.Math in File2 breaks File1 regardless of where the using goes. This implies that the compiler searches the innermost enclosing namespace before it looks at any using directive.

Fetching values from the repeater control in ItemDataBound event

First of all in markup use Text property of label, do not put databinder.Eval in

<asp:Label ..> do not put content here </asp:Label>

In item databound event first find out control in which template.

follow this example :

Markup:

<asp:Repeater ID="Repeater1" runat="server" 
                    onitemdatabound="Repeater1_ItemDataBound">                
                <HeaderTemplate>
                </HeaderTemplate>
                <ItemTemplate>
                    <asp:Label ID="Label1" runat="server" Text='<%# Eval("content") %>'></asp:Label>
                    <asp:LinkButton ID="LinkButton1" runat="server">LinkButton</asp:LinkButton>
                </ItemTemplate>
                <AlternatingItemTemplate></AlternatingItemTemplate>
                <SeparatorTemplate></SeparatorTemplate>
            </asp:Repeater>

Source Code :

C#:

protected void Repeater1_ItemDataBound(object sender, RepeaterItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Item)
        {
            Label lbl = (Label)e.Item.FindControl("Label1");
            LinkButton link = (LinkButton)e.Item.FindControl("LinkButton1");
            link.PostBackUrl = "abcd/" + lbl.Text;
        }
    }

VB.Net:

Protected Sub Repeater1_ItemDataBound(sender As Object, e As RepeaterItemEventArgs)
    If e.Item.ItemType = ListItemType.Item Then
        Dim lbl As Label = DirectCast(e.Item.FindControl("Label1"), Label)
        Dim link As LinkButton = DirectCast(e.Item.FindControl("LinkButton1"), LinkButton)
        link.PostBackUrl = "abcd/" + lbl.Text
    End If
End Sub

Best Answer

Related Solutions

C# – Should ‘using’ directives be inside or outside the namespace

Fetching values from the repeater control in ItemDataBound event

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