Image Button does not hide on page load

Question

I used code below to hide template field Imagebutton on pageload but it DOES NOT work, Thanks in advance:

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
            Dim ImageButton1 As ImageButton = DirectCast(GridView1.FindControl("ImageButton1"), ImageButton)
            If User.Identity.Name.Substring(InStr(User.Identity.Name, "\")).ToUpper = "User1" Then
                ImageButton1.Visible = False
            End If
        End Sub

Answer 1

Assuming you have binding grid before and it has rows . Find the ImageButton in some row of grid instead of find within gridview . The if condition you have seems to never get true, as you are comparing string after ToUpper with a string that is not in upper case, Change User1 to USER1 As you are using ToUpper.

Change

 Dim ImageButton1 As ImageButton = DirectCast(GridView1.FindControl("ImageButton1"), ImageButton) 
 If User.Identity.Name.Substring(InStr(User.Identity.Name, "\")).ToUpper = "User1" Then
            ImageButton1.Visible = False
 End If

To

   Dim ImageButton1 As ImageButton = DirectCast(GridView1.Rows(0).FindControl("ImageButton1"), ImageButton)
 If User.Identity.Name.Substring(InStr(User.Identity.Name, "\")).ToUpper = "USER1" Then
       ImageButton1.Visible = False
 End If

Iterating whole grid by loop

For Each row As GridViewRow In GridView1.Rows
 Dim ImageButton1 As ImageButton = DirectCast(row.FindControl("ImageButton1"), ImageButton)
     If User.Identity.Name.Substring(InStr(User.Identity.Name, "\")).ToUpper = "USER1" Then
           ImageButton1.Visible = False
     End If
Next