Whats wrong with this?

[ryans]

This is the error message given when i try and draw a rectangle

An unhandled exception of type 'System.ArgumentException' occurred in system.drawing.dll

Additional information: Invalid parameter used.

I get an error from this code:

Private Sub picBoard_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles picImage.MouseMove
If isDragging Then
Dim gr As Graphics = picImage.CreateGraphics
gr.Clear(picImage.BackColor)

Dim rect As New Rectangle(startX, startY, e.X - startX, e.Y - startY)
gr.DrawRectangle(Pens.Red, rect)
gr.FillRectangle(Brushes.Transparent, rect)
Dim bmpCropped As New Bitmap(e.X - startX, e.Y - startY)

Dim grBitmap As Graphics = Graphics.FromImage(bmpCropped)

grBitmap.DrawImage(picImage.Image, 0, 0, rect, _
GraphicsUnit.Pixel)
picImage.Image = bmpCropped
picImage.SizeMode = PictureBoxSizeMode.Normal
gr.Dispose()
End If
End Sub


This is supposed to crop the image from the rectangle drawn.
the error is from this line of code because it accepts invalid inputs i think.

Dim bmpCropped As New Bitmap(e.X - startX, e.Y - startY)

[Lunatic3]

Are you sure the dimensions of the bitmap you are trying to create won't become negative? Try using absolute values of e.X - startX and e.Y - startY

[ryans]

Originally posted by Lunatic3
Are you sure the dimensions of the bitmap you are trying to create won't become negative? Try using absolute values of e.X - startX and e.Y - startY

How do i use absolute values?

[Lunatic3]

Use Math.Abs method.