maintaining the tab order on page postback

The code to set focus to the next control after a postback is given below:

C#

protected void Page_Load(object sender, EventArgs e)

{

if (Page.IsPostBack)

{

WebControl wcICausedPostBack = (WebControl)GetControlThatCausedPostBack(sender as Page);

int indx = wcICausedPostBack.TabIndex;

var ctrl = from control in wcICausedPostBack.Parent.Controls.OfType<WebControl>()

where control.TabIndex > indx

select control;

ctrl.DefaultIfEmpty(wcICausedPostBack).First().Focus();

}

}

protected Control GetControlThatCausedPostBack(Page page)

{

Control control = null;

string ctrlname = page.Request.Params.Get("__EVENTTARGET");

if (ctrlname != null && ctrlname != string.Empty)

{

control = page.FindControl(ctrlname);

}

else

{

foreach (string ctl in page.Request.Form)

{

Control c = page.FindControl(ctl);

if (c is System.Web.UI.WebControls.Button || c is System.Web.UI.WebControls.ImageButton)

{

control = c;

break;

}

}

}

return control;

}

VB.NET

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

If Page.IsPostBack Then

Dim wcICausedPostBack As WebControl = CType(GetControlThatCausedPostBack(TryCast(sender, Page)), WebControl)

Dim indx As Integer = wcICausedPostBack.TabIndex

Dim ctrl = _

From control In wcICausedPostBack.Parent.Controls.OfType(Of WebControl)() _

Where control.TabIndex > indx _

Select control

ctrl.DefaultIfEmpty(wcICausedPostBack).First().Focus()

End If

End Sub

Protected Function GetControlThatCausedPostBack(ByVal page As Page) As Control

Dim control As Control = Nothing

Dim ctrlname As String = page.Request.Params.Get("__EVENTTARGET")

If ctrlname IsNot Nothing AndAlso ctrlname <> String.Empty Then

control = page.FindControl(ctrlname)

Else

For Each ctl As String In page.Request.Form

Dim c As Control = page.FindControl(ctl)

If TypeOf c Is System.Web.UI.WebControls.Button OrElse TypeOf c Is System.Web.UI.WebControls.ImageButton Then

control = c

Exit For

End If

Next ctl

End If

Return control

End Function