.rectangle.offset? (vb.net)

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I’m trying to learn vb.net, the problem i’m having in working with the system.drawing class. I draw a rectangle and want to move it. The offset method seems to be designed to do this. but I can’t seem to make it work. here’s a snippet of code, any sugesstions are appreciated

Public Class frmLights
Inherits System.Windows.Forms.Form

Dim grpGraphics As System.Drawing.Graphics
Dim mrecSquare As New System.Drawing.Rectangle(32, 120, 20, 20))

Private Sub btnSquare_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSquare.Click
Dim bshDraw As System.Drawing.Brush
bshDraw = New SolidBrush(Color.Crimson)
grpGraphics = Me.CreateGraphics
grpGraphics.FillRectangle(bshDraw, mrecSquare)
End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
mrecSquare.Offset(5, 5)
End Sub
end class

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Three ideas for you:

1) There is an extra closing paranthesis around the following line: Dim mrecSquare As New System.Drawing.Rectangle(32, 120, 20, 20)) – Remove this
2) Move your Brush object into the Class scope [as opposed to being inside the Sub btn_Square_Click() scope]
3) Re-call the line filling the rectangle object with color [grpGraphics.FillRectangle(bshDraw, mrecSquare)] after calling the Offset method.

Explanation:
The Offset method does exactly what you expect. The problem is that the offset rectangle is no longer filled since the brush (coloring the rectangle) is limited only to the first sub. Moving the brush into the class-level scope will make it persist beyond the initial sub. You will see that a result of this is that the previous rectangles stay in addition to the new, offset rectangles. If you want to get around this, simply add a Me.Refresh line before the second call to the FillRectangle method.

Please post back with any further questions. Good luck!

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thanks,
the extra parens were a typo copying it to the forum, changing the scope works, I would preferr the square didn’t leave residuals but I can work around that.

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thanks,
the extra parens were a typo copying it to the forum, changing the scope works, I would preferr the square didn’t leave residuals but I can work around that.

Reply | Quote

Three ideas for you:

1) There is an extra closing paranthesis around the following line: Dim mrecSquare As New System.Drawing.Rectangle(32, 120, 20, 20)) – Remove this
2) Move your Brush object into the Class scope [as opposed to being inside the Sub btn_Square_Click() scope]
3) Re-call the line filling the rectangle object with color [grpGraphics.FillRectangle(bshDraw, mrecSquare)] after calling the Offset method.

Explanation:
The Offset method does exactly what you expect. The problem is that the offset rectangle is no longer filled since the brush (coloring the rectangle) is limited only to the first sub. Moving the brush into the class-level scope will make it persist beyond the initial sub. You will see that a result of this is that the previous rectangles stay in addition to the new, offset rectangles. If you want to get around this, simply add a Me.Refresh line before the second call to the FillRectangle method.

Please post back with any further questions. Good luck!

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