how to find user control's id in aspx page

Question

I have an aspx web application in which 1 aspx page and 1 web user controls exist. I added 4 instances of the user control in aspx page. There is a remove button in user control which is used to remove the control from the aspx page. If I click on remove button of the user control, how can I find that which user control's remove button is clicked from the aspx page. Please let me know the solution...

Thanks in advance :)

Answer 1

I would add an event to the User Control and capture that event in the code behind. Here's an example:

Default.aspx Web Form:

Register the user control:

<%@ Register TagPrefix="so" TagName="UserControl" Src="~/WebUserControl.ascx" %>

4 instances of the above control. Note we're handling the OnRemoving event defined below:

    <so:UserControl ID="UserControl1" runat="server" Title="Control 1" OnRemoving="UserControl1_Removing" />
    <so:UserControl ID="UserControl2" runat="server" Title="Control 2" OnRemoving="UserControl2_Removing" />
    <so:UserControl ID="UserControl3" runat="server" Title="Control 3" OnRemoving="UserControl3_Removing" />
    <so:UserControl ID="UserControl4" runat="server" Title="Control 4" OnRemoving="UserControl4_Removing" />

Default.aspx Code Behind:

In the code behind, I handle each of the control's OnRemoving events:

protected void UserControl1_Removing(object sender, EventArgs e)
{
    WebUserControl ctrl = (WebUserControl)sender;
    ctrl.Visible = false;
}
protected void UserControl2_Removing(object sender, EventArgs e)
{
    WebUserControl ctrl = (WebUserControl)sender;
    ctrl.Visible = false;
}
protected void UserControl3_Removing(object sender, EventArgs e)
{
    WebUserControl ctrl = (WebUserControl)sender;
    ctrl.Visible = false;
}
protected void UserControl4_Removing(object sender, EventArgs e)
{
    WebUserControl ctrl = (WebUserControl)sender;
    ctrl.Visible = false;
}

User Control Web Form:

The web user control includes a "remove" button:

<%@ Control Language="C#" AutoEventWireup="true" CodeFile="WebUserControl.ascx.cs" Inherits="WebUserControl" %>

<fieldset>
  <legend><%=Title %></legend>
  <asp:Button ID="Button_Remove" runat="server" Text="Remove" OnClick="Button_Remove_Click" />
</fieldset>

User Control Code Behind:

Finally, here's how to code the event for the user control:

public partial class WebUserControl : System.Web.UI.UserControl
{
    // the event delegates may listen for
    public event EventHandler Removing;
    public string Title { get; set; }

    protected void Page_Load(object sender, EventArgs e)
    {
    }

    protected void Button_Remove_Click(object sender, EventArgs e)
    {
        // raise the event for attached delegates
        if (Removing != null)
            Removing(this, EventArgs.Empty);
    }
}

Final Result:

The above example produces the following web page. When a remove button is clicked, that control disappears:

Good luck!!