Question

I am trying to handle a button click event of a dynamically loaded usercontrol from my host page. My relevant code is posted below, I think I’m on the right path but what else do I need to make this function properly? I am currently receiveing “Error binding to target method.” when I try to create the usercontrol. Thanks in advance for any assistance!

aspx

<asp:UpdatePanel ID="upLeadComm" runat="server" UpdateMode="Conditional">
    <ContentTemplate>
        <asp:PlaceHolder ID="phComm" runat="server"></asp:PlaceHolder>
    </ContentTemplate>
</asp:UpdatePanel>

aspx.cs

else if (e.CommandName == "GetComm")
{
    string[] cplArg = e.CommandArgument.ToString().Split('§');

    UserControl ucLeadComm = (UserControl)LoadControl("Controls/Comments.ascx");

    // Set the Usercontrol Type 
    Type ucType = ucLeadComm.GetType();

    // Get access to the property 
    PropertyInfo ucPropLeadID = ucType.GetProperty("LeadID");
    PropertyInfo ucPropLeadType = ucType.GetProperty("LeadType");

    EventInfo ucEventInfo = ucType.GetEvent("BtnCommClick");
    MethodInfo ucMethInfo = ucType.GetMethod("btnComm_Click");
    Delegate handler = Delegate.CreateDelegate(ucEventInfo.EventHandlerType, ucType, ucMethInfo);
    ucEventInfo.AddEventHandler(ucType, handler);

    // Set the property 
    ucPropLeadID.SetValue(ucLeadComm, Convert.ToInt32(cplArg[0]), null);
    ucPropLeadType.SetValue(ucLeadComm, cplArg[1], null);

    phComm.Controls.Add(ucLeadComm);

   upLeadComm.Update();
}

ascx.cs

public int LeadID { get; set; }
public string LeadType { get; set; }
public event EventHandler BtnCommClick;

public void btnComm_Click(object sender, EventArgs e)
{
    BtnCommClick(sender, e);
}

Answer 1

I am receiving the error from this line: Delegate handler =
Delegate.CreateDelegate(ucEventInfo.EventHandlerType, ucType,
ucMethInfo);

The problem is that your passing ucType while you should pass an instance of your UserControl, so try to do:

Delegate handler = Delegate.CreateDelegate(ucEventInfo.EventHandlerType, ucLeadComm, ucMethInfo);

I’m not sure that ucLeadComm is an istance of the UserControl because I’ve never used LoadControl(), so if it isn’t use: Activator.CreateInstance(); or use GetContructor() and Invoke() it to create an instance of your object.

EDIT 1:

Thanks for the responses, I now receive “Object does not match target
type.” on the next line: ucEventInfo.AddEventHandler(ucType, handler);

Also in that line you should pass an instance of your UserControl instead of ucType.

EDIT 2:

Many thanks for the assistance! The project builds and does not throw
any errors. However, how do I go about tying this back into a method
within the aspx page to actually do something when the button is
clicked?

If I understood in this case you should create the method in your aspx.cs:

public void btnComm_Click(object sender, EventArgs e)
{
   //Here what you want to do in the aspx.cs
}

And then create another handler creating a MethodInfo tied to btnComm_Click contained in the aspx.cs and passing it to Delegate.CreateDelegate():

MethodInfo ucMethInfo = this.GetType().GetMethod("btnComm_Click");