How to Compare Variable to PictureBox Image

Question

    If PictureBox1.Image = "a.png" Then
        PictureBox1.Image = My.Resources.b
    Else
        PictureBox1.Image = My.Resources.a
    End If

It won't work. How do i make this thing working? It shoud check if the picture box is showing the picture a , if yes then make it showing picture b.

Public Class Form1
    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick 
        If PictureBox1.Image Is My.Resources.b Then
            PictureBox1.Image = My.Resources.a
            PictureBox1.Refresh()
        Else
            PictureBox1.Image = My.Resources.b
            PictureBox1.Refresh()
        End If
    End Sub
End Class

Thats the complete code

First of all: project properties: option strict on, option explicit on — Morcilla de Arroz, Oct 28 '15 at 11:41

score 2 · Accepted Answer · edited May 23 '17 at 12:29

Image is a Property of type System.Drawing.Image whereas "a.png" is a string so you can't compare these things to see if they are equal.

Also Image is a reference type, so you must use Is to compare it to another reference type.

The following might work:

If PictureBox1.Image Is My.Resources.a Then
    PictureBox1.Image = My.Resources.b
Else
    PictureBox1.Image = My.Resources.a
End If

Note: Comparing images can be tricky because when you set an Image property it may actually create a copy of the original image, so then comparison later does not work. See How to compare Image objects with C# .NET?

So taking that into account, it would be a better idea to use a variable to compare the state as this consumes less resources and is far simpler than having to compare images.

Something like the following should work for you:

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
    Static showImageA As Boolean
    showImageA = Not showImageA

    If showImageA Then
        PictureBox1.Image = My.Resources.a
    Else
        PictureBox1.Image = My.Resources.b
    End If
End Sub

Note: make sure you have Option Strict and Option Explicit On because the code you posted does not compile when you do this and so points out the errors to you.

Thank you it solved the errors, but it still doesnt change the picture. Can you help me again? — , Oct 28 '15 at 12:00
Sounds like you have another issue then. If you are doing this in a loop then try `PictureBox1.Refresh` after you set the image as a quick fix. — Matt Wilko, Oct 28 '15 at 12:02
`Public Class Form1 Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick If PictureBox1.Image Is My.Resources.b Then PictureBox1.Image = My.Resources.a PictureBox1.Refresh() Else PictureBox1.Image = My.Resources.b PictureBox1.Refresh() End If End Sub End Class ` — , Oct 28 '15 at 12:05

How to Compare Variable to PictureBox Image

1 Answers1