Forcing CreateGraphics. DrawRectangle to Draw rectangle on top

[Jeff Waskiewicz]

Hello All,

I'm trying to solve a nagging problem. The goal is to draw a rectangle over
the top of all the other controls on a form. Specifically, over a ChartFX
control. The user would draw the rectangle using the right mouse button to
represent the area of the chart they want to zoom on. I haev been able to
draw the rectangle on a blank form but I cannot get it to draw on top of
other controls. I have pasted in the code i am using . Is there a way to
force the rectangle to draw on the 'top layer'? Or is there another method
to draw the rectangle entirely that will accomplish what I am looking for?

Thanks

Jeff

Imports System.Drawing
Imports System.Drawing. Drawing2D

Public Class Form1
Inherits System.Windows. Forms.Form

#Region " Windows Form Designer generated code "

Public Sub New()
MyBase.New()

'This call is required by the Windows Form Designer.
InitializeCompo nent()

'Add any initialization after the InitializeCompo nent() call

End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Disp ose()
End If
End If
MyBase.Dispose( disposing)
End Sub

'Required by the Windows Form Designer
Private components As System.Componen tModel.IContain er

'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
<System.Diagnos tics.DebuggerSt epThrough()Priv ate Sub
InitializeCompo nent()
'
'Form1
'
Me.AutoScaleBas eSize = New System.Drawing. Size(5, 13)
Me.ClientSize = New System.Drawing. Size(600, 558)
Me.Name = "Form1"
Me.Text = "Form1"

End Sub

#End Region
Dim f_zoomX As Integer
Dim f_zoomY As Integer
Dim f_zoomWidth As Integer
Dim f_zoomHeight As Integer

Public f_zoomRectPen As Pen

Public f_zoomRectPenSi ze As Integer = 2
Public f_zoomRectPenDa shStyle As Drawing2D.DashS tyle =
Drawing2D.DashS tyle.Dash

Public f_zoomRectPenCo lor As Color = Color.Black
Private Sub Form1_MouseDown (ByVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles MyBase.MouseDow n

Try

If e.Button = MouseButtons.Ri ght Then

f_zoomX = e.X
f_zoomY = e.Y

f_zoomRectPen = New Pen(f_zoomRectP enColor, f_zoomRectPenSi ze)
f_zoomRectPen.D ashStyle = f_zoomRectPenDa shStyle

Cursor = Cursors.Cross

End If

Me.Refresh()

Catch exc As Exception

MessageBox.Show (exc.Message, " Error", MessageBoxButto ns.OK,
MessageBoxIcon. Error)

End Try

End Sub

Private Sub Form1_MouseMove (ByVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles MyBase.MouseMov e

Try

If e.Button = MouseButtons.Ri ght Then

Me.Refresh()

f_zoomWidth = e.X - f_zoomX
f_zoomHeight = e.Y - f_zoomY

Me.CreateGraphi cs.DrawRectangl e(f_zoomRectPen , f_zoomX,
f_zoomY, f_zoomWidth, f_zoomHeight)
End If

GC.Collect()

Catch exc As Exception

If Err.Number = 5 Then Exit Sub

MessageBox.Show (exc.Message, " Error", MessageBoxButto ns.OK,
MessageBoxIcon. Error)

End Try

End Sub

Private Sub Form1_MouseUp(B yVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles MyBase.MouseUp

Try

Cursor = Cursors.Default

Catch exc As Exception

MessageBox.Show (exc.Message, " Error", MessageBoxButto ns.OK,
MessageBoxIcon. Error)

End Try

End Sub

End Class

[Stuart Nathan]

You need to be able to use controls that allow a userdraw mode