how to find user control's id in aspx page

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开发者_高级运维 know the solution...

Thanks in advance :)

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!!

If you're trying to do this client-side you can reference the ID like this:

var removeButtonId = "<%=removeButton.ClientID %>";

If you've wired up a click event you can get it from the sender parameter like so:

void removeButton_Click(object sender, EventArgs e)
{
    Button removeButton = sender as Button;
    string id = removeButton.ID;
}

An easy way: have the user control implement a RemoveClicked event. Then, when the delete button is clicked, in the button click event handler, fire the RemoveClicked event. The page can know which user control the remove request came from. You can even pass the button through the event args too, if you like. The page would have to attach to this event for all 4 user controls too, FYI.

This advice assumes you are looking for a server-side solution, not a client side one.

HTH.