ASP.NET

public override void Initialize(IComponent component)
{
      //Your code to verify if the component is of the expected type.
                 
      base.Initialize(component);
}

		<br />
  public override void Initialize(IComponent component)<br />
  {<br />
    base.Initialize(component);<br />
<br />
    try<br />
    {<br />
      MyComponent o = (MyComponent)component;<br />
    }<br />
    catch (Exception ex)<br />
    {<br />
      string s = ex.Message;<br />
    }<br />
  }

[ToolboxData("<{0}:MyComponent runat=\"server\"></{0}:MyComponent>"), Designer(typeof(MyDesigner)), ParseChildren(false)]
public class MyComponent : View, INamingContainer
{
    public MyComponent()
    {
    }
             
    private string myVar;
                    
    public string MyProperty
    {
        get { return myVar; }
        set { myVar = value; }
    }
}
           
public class MyDesigner : ViewDesigner
{
    string error = string.Empty;
              
    public override void Initialize(IComponent component)
    {
        base.Initialize(component);
                 
        try
        {
            MyComponent o = (MyComponent)component;
        }
        catch (Exception ex)
        {
            error = ex.Message;
        }
    }
                     
    public override string FrameCaption
    {
        get
        {
            if (!string.IsNullOrEmpty(error))
                return error;
                     
            MyComponent c = (MyComponent)base.Component;
            return "MyComponent - " + c.MyProperty;
        }
    }
}

<asp:MultiView ID="MultiView1" runat="server" ActiveViewIndex="1">
    <asp:View ID="View1" runat="server">
        <asp:TextBox ID="TextBox1" runat="server" Text="dsd"></asp:TextBox></asp:View>
    <cc1:MyComponent ID="MyComponent1" runat="server" MyProperty="My Custom View">
        <asp:Button id="Button1" runat="server" Text="Pushed Me!" />
    </cc1:MyComponent>
</asp:MultiView>

minhpc_bk wrote:

+ Do you get the error right after you add the control onto the web page or after you do something and the error occurs?

minhpc_bk wrote:

+ If you manually add the custom component in the source view and switch back to the Design view, do you still get the error?

minhpc_bk wrote:

+ Do you plan to use the MyComponent with the MultiView control?