CODEWITHSUNDEEP
vb.netvisual-studio
user2087008
user2087008

Reputation:

Operator '=' is not defined for types 'System.Windows.Forms.Listbox' and 'Integer'

I have this code:

Public Class Form1
Private _Previous As System.Nullable(Of Point) = Nothing
Private Sub pictureBox1_MouseDown(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseDown
    _Previous = e.Location
    pictureBox1_MouseMove(sender, e)
End Sub

Private Sub PictureBox1_MouseMove(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseMove
    Dim Marker As Integer
    Marker = Lst_Markers.SelectedIndex + 1
    If _Previous IsNot Nothing Then
        For i As Integer = 0 To Marker
            Dim bmp As New Bitmap(PictureBox1.Width, PictureBox1.Height)
            PictureBox1.Image = bmp
        Next
        Select Case Lst_Markers

            Case 1
                Using g As Graphics = Graphics.FromImage(PictureBox1.Image)
                    g.FillEllipse(Brushes.Red, e.X, e.Y, 10, 10)
                End Using
            Case 2

                Using g As Graphics = Graphics.FromImage(PictureBox1.Image)
                    g.FillEllipse(Brushes.Yellow, e.X, e.Y, 10, 10)
                End Using
            Case 3

                Using g As Graphics = Graphics.FromImage(PictureBox1.Image)
                    g.FillEllipse(Brushes.Green, e.X, e.Y, 10, 10)
                End Using
            Case 4

                Using g As Graphics = Graphics.FromImage(PictureBox1.Image)
                    g.FillEllipse(Brushes.Blue, e.X, e.Y, 10, 10)
                End Using
            Case Else
                MsgBox("Select a marker")
        End Select
        PictureBox1.Invalidate()
        _Previous = e.Location
    End If
End Sub

Private Sub pictureBox1_MouseUp(sender As Object, e As MouseEventArgs) Handles PictureBox1.MouseUp
    _Previous = Nothing
End Sub
End Class

However I am getting the error in my question title. The problem is the 'Case 1', 'Case 2', 'Case 3', 'Case 4' statements, I am wondering what I've done wrong, and I think the problem lies in my Marker = Lst_Markers.SelectedIndex + 1 line, is this right?

Upvotes: 1

Views: 2583

Answers (5)

Simon Jensen
Simon Jensen

Reputation: 486

Why don't you just get rid of Marker all together by using: Select Case Lst_Markers.SelectedIndex + 1

But just out of curiosity what is the function of the For each loop you have?

    For i As Integer = 0 To Marker
        Dim bmp As New Bitmap(PictureBox1.Width, PictureBox1.Height)
        PictureBox1.Image = bmp
    Next

I really don't see the point in doing this several times, for example:
If you chose green this till run 5 times, where if you chose red this will only run twice.

I tested out your code without the For each look and only had the two lines:

    Dim bmp As New Bitmap(PictureBox1.Width, PictureBox1.Height)
    PictureBox1.Image = bmp

The code seems to work just the same as if it was in a For each loop.

Upvotes: 0

neminem
neminem

Reputation: 2698

I can't say for sure, as Lst_Markers isn't defined in the code you quoted, but given the error, it would appear Lst_Markers is a Listbox. Listboxes aren't integers, so what does Select Case Lst_Markers mean? I don't think that's the variable you intended to select on. (You probably meant Marker.)

Upvotes: 0

logixologist
logixologist

Reputation: 3834

LST_Markers is a ListBox and cant be compared to a integer. I think you meant LST_Markers.selectedIndex in your case statement.

Upvotes: 0

vbigham
vbigham

Reputation: 191

Try using your integer variable in the select statement.

Select Case Marker

instead of:

Select Case Lst_Markers

Upvotes: 0

RichieHindle
RichieHindle

Reputation: 281695

Did you mean Select Case Marker rather than Select Case Lst_Markers?

You can't compare Lst_Markers with the integers in your Case statements - comparing a control with an integer is meaningless. If you want to compare the selected index, Marker seems like what you should be comparing with.

Upvotes: 2

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