Visual Basic循环控件

Question

I have a web application that I'm writing. I have a lot of buttons, all named the same thing except with a number appended (button1,button2,button3...etc.). All of these are in a panel named Panel3. I would like to loop through these blank ImageButtons and set their image using .ImageUrl. I know my getIconImage() function works.

    Dim cntrl As Control
    For Each cntrl In Me.Panel3.Controls

        cntrl.ImageUrl = getIconImage(4)

    Next

The problem is "cntrl" does not recognize .ImageUrl as an option. It is like it doesn't recognize itself as an ImageButton. I am using asp.net and vb.net. Thanks!

(as a note: I have also tried "Me.Controls" with no such luck. Also, I have tried setting a temporary ImageButton object equal to "cntrl" and modifying the .ImageUrl from there.)

Answer 1

You don't say what the issue is so i'll assume you need to check which type of control you are getting in the loop:

 Dim cntrl As Control
 For Each cntrl In Me.Panel3.Controls
    if TypeOf cntrl Is ImageButton Then 
       cntrl.ImageUrl = getIconImage(4)
    End if
 Next

Answer 2

Try this:

For Each cntrl As ImageButton In Me.Panel3.Controls.OfType(Of ImageButton)

May have to do Imports System.Linq