ASP.NET Tutorial/Custom Controls/PostBack

Adding PostBack capabilities to a server control (C#)

using System.ruponentModel;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebControlLibrary1
{
    [DefaultProperty("Text")]
    [ToolboxData("<{0}:WebCustomControl3 runat=server></{0}:WebCustomControl3>")]
    public class WebCustomControl3 : WebControl
    {
        protected override void Render(HtmlTextWriter output)
        {
            PostBackOptions p = new PostBackOptions(this);
            output.AddAttribute(HtmlTextWriterAttribute.Onclick,
                Page.ClientScript.GetPostBackEventReference(p));
            output.AddAttribute(HtmlTextWriterAttribute.Value, "My Button");
            output.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID);
            output.AddAttribute(HtmlTextWriterAttribute.Name, this.ClientID);
            output.RenderBeginTag(HtmlTextWriterTag.Button);
            output.RenderEndTag();
        }
    }
}

Adding PostBack capabilities to a server control (VB)

Imports System.ruponentModel
Imports System.Web.UI
<DefaultProperty("Text")> _
<ToolboxData("<{0}:WebCustomControl3 runat=server></{0}:WebCustomControl3>")> _
Public Class WebCustomControl3
    Inherits System.Web.UI.WebControls.WebControl
    Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)
        Dim p As New PostBackOptions(Me)
        output.AddAttribute(HtmlTextWriterAttribute.Onclick, _
            Page.ClientScript.GetPostBackEventReference(p))
        output.AddAttribute(HtmlTextWriterAttribute.Value, "My Button")
        output.AddAttribute(HtmlTextWriterAttribute.Id, Me.ClientID)
        output.AddAttribute(HtmlTextWriterAttribute.Name, Me.ClientID)
        output.RenderBeginTag(HtmlTextWriterTag.Button)
        output.RenderEndTag()
    End Sub
End Class

Handling postback events in a server control (C#)

using System.ruponentModel;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace WebControlLibrary1
{
    [DefaultProperty("Text")]
    [ToolboxData("<{0}:WebCustomControl3 runat=server></{0}:WebCustomControl3>")]
    public class WebCustomControl3 : WebControl, IPostBackEventHandler
    {
        protected override void Render(HtmlTextWriter output)
        {
            PostBackOptions p = new PostBackOptions(this);
            output.AddAttribute(HtmlTextWriterAttribute.Onclick,Page.ClientScript.GetPostBackEventReference(p));
            output.AddAttribute(HtmlTextWriterAttribute.Value, "My Button");
            output.AddAttribute(HtmlTextWriterAttribute.Id, this.ClientID);
            output.AddAttribute(HtmlTextWriterAttribute.Name, this.ClientID);
            output.RenderBeginTag(HtmlTextWriterTag.Button);
            output.RenderEndTag();
        }
        #region IPostBackEventHandler Members
        public event EventHandler Click;
        public virtual void OnClick(EventArgs e)
        {
            if (Click != null)
            {
                Click(this, e);
            }
        }
        public void RaisePostBackEvent(string eventArgument)
        {
            OnClick(EventArgs.Empty);
        }
        #endregion
    
    }
}

Handling postback events in a server control (VB)

Imports System.ruponentModel
Imports System.Web.UI
<DefaultProperty("Text")> _
<ToolboxData("<{0}:WebCustomControl3 runat=server></{0}:WebCustomControl3>")> _
Public Class WebCustomControl3
    Inherits System.Web.UI.WebControls.WebControl
    Implements IPostBackEventHandler
    Protected Overrides Sub Render(ByVal output As System.Web.UI.HtmlTextWriter)
        Dim p As New PostBackOptions(Me)
        output.AddAttribute(HtmlTextWriterAttribute.Onclick, _
            Page.ClientScript.GetPostBackEventReference(p))
        output.AddAttribute(HtmlTextWriterAttribute.Value, "My Button")
        output.AddAttribute(HtmlTextWriterAttribute.Id, Me.ClientID)
        output.AddAttribute(HtmlTextWriterAttribute.Name, Me.ClientID)
        output.RenderBeginTag(HtmlTextWriterTag.Button)
        output.RenderEndTag()
    End Sub
    Public Event Click()
    Public Sub OnClick(ByVal args As EventArgs)
        RaiseEvent Click()
    End Sub
    Public Sub RaisePostBackEvent(ByVal eventArgument As String) Implements System.Web.UI.IPostBackEventHandler.RaisePostBackEvent
        OnClick(EventArgs.Empty)
    End Sub
End Class