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May 30th, 2005
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How to draw a line in a VB.NET form?

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hi guys!
can anyone tell me now to draw a line in VB.NET form?
I've been trying to do so , but nothings coming..
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gminhas is offline Offline
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Jun 13th, 2005
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Re: How to draw a line in a VB.NET form?

There are lot more capabilities in VB.NET than in VB6 -

check out:
http://msdn.microsoft.com/library/de...LineOnForm.asp
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srikkanthan is offline Offline
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Re: How to draw a line in a VB.NET form?

VB.NET Syntax (Toggle Plain Text)
  1. Here is the old VB6 Way
  2.  
  3. Private Sub DrawLine()
  4.  
  5. Dim bit As Bitmap = New Bitmap(Me.Width, Me.Height)
  6.  
  7. Dim g As Graphics = Graphics.FromImage(bit)
  8.  
  9. Dim myPen As Pen = New Pen(Color.Blue, 3)
  10.  
  11. Me.CreateGraphics.DrawLine(myPen, 0, 0, Me.Width, Me.Height)
  12.  
  13. End Sub

Here is the C# .NET way

VB.NET Syntax (Toggle Plain Text)
  1.  
  2. protected override void OnPaint(PaintEventArgs pe)
  3. {
  4.  
  5. Graphics g = pe.Graphics ;
  6. Pen pn = new Pen( Color.Blue );
  7. // Rectangle rect = new Rectangle(50, 50, 200, 100);
  8. Point pt1 = new Point( 30, 30);
  9. Point pt2 = new Point( 110, 100);
  10. g.DrawLine( pn, pt1, pt2 );
  11.  
  12. }

Here is the VB .NET way

VB.NET Syntax (Toggle Plain Text)
  1. ' True while we are drawing the new line.
  2. Private m_Drawing As Boolean
  3.  
  4. ' Buffer for erasing rubberband lines.
  5. Private m_BufferBitmap As Bitmap
  6. Private m_BufferGraphics As Graphics
  7.  
  8. ' The mouse position.
  9. Private m_X1 As Integer
  10. Private m_Y1 As Integer
  11. Private m_X2 As Integer
  12. Private m_Y2 As Integer
  13.  
  14. ' Start drawing a rubberband line.
  15. Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e _
  16. As System.Windows.Forms.MouseEventArgs) Handles _
  17. MyBase.MouseDown
  18. ' Do nothing if this isn'tthe left mouse button.
  19. If e.Button <> MouseButtons.Left Then Exit Sub
  20. m_Drawing = True
  21.  
  22. ' Save a snapshot of the form.
  23. SaveSnapshot()
  24.  
  25. ' Save the current mouse position.
  26. m_X1 = e.X
  27. m_X2 = e.X
  28. m_Y1 = e.Y
  29. m_Y2 = e.Y
  30. End Sub
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techniner is offline Offline
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Re: How to draw a line in a VB.NET form?

what is the SaveSnapshot() method?????
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Tbusuk is offline Offline
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Re: How to draw a line in a VB.NET form?

there are two ways, the plain old line way, and the way using GDI and pens.
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jbennet is offline Offline
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Apr 2nd, 2009
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Re: How to draw a line in a VB.NET form?

Click to Expand / Collapse  Quote originally posted by gminhas ...
hi guys!
can anyone tell me now to draw a line in VB.NET form?
I've been trying to do so , but nothings coming..

Hi there,

i was fetching the same thing, it about using the mouse down and mouse up and mouse move events on the form, you have to start drawing on mouse down and stop on mouse up, here is the code you have to put in a new form:

' True while we are drawing the new line.
Private m_Drawing As Boolean

' Buffer for erasing rubberband lines.
Private m_BufferBitmap As Bitmap
Private m_BufferGraphics As Graphics

' The mouse position.
Private m_X1 As Integer
Private m_Y1 As Integer
Private m_X2 As Integer
Private m_Y2 As Integer

' Start drawing a rubberband line.
Private Sub Form1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseDown
' Do nothing if this isn'tthe left mouse button.
If e.Button <> MouseButtons.Left Then Exit Sub
m_Drawing = True

' Save a snapshot of the form.
SaveSnapshot()

' Save the current mouse position.
m_X1 = e.X
m_X2 = e.X
m_Y1 = e.Y
m_Y2 = e.Y
End Sub

Private Sub SaveSnapshot()
Dim new_bitmap As Bitmap

' Make a new bitmap that fits the form.
new_bitmap = New Bitmap(Me.Size.Width, Me.Size.Height, Me.CreateGraphics())
m_BufferGraphics = Graphics.FromImage(new_bitmap)

' Clear the new bitmap.
m_BufferGraphics.Clear(Me.BackColor)

' Copy the existing bitmap's contents into
' the new bitmap.
If Not (m_BufferBitmap Is Nothing) Then
m_BufferGraphics.DrawImage(m_BufferBitmap, 0, 0)
End If

' Save the new bitmap and graphics objects.
m_BufferBitmap = new_bitmap
End Sub

' Continue drawing the rubberband line.
Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
' Do nothing if we're not drawing.
If Not m_Drawing Then Exit Sub

' Save the new point.
m_X2 = e.X
m_Y2 = e.Y

' Erase the previous line.
DrawForm(Me.CreateGraphics())

' Draw the new line directly on the form.
Me.CreateGraphics().DrawLine( _
Pens.Gray, m_X1, m_Y1, m_X2, m_Y2)
End Sub

' Redraw the saved buffer.
Private Sub DrawForm(ByVal gr As Graphics)
If Not (m_BufferBitmap Is Nothing) Then gr.DrawImage(m_BufferBitmap, 0, 0)
End Sub

' Finish drawing the new line.
Private Sub Form1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseUp
' Do nothing if we're not drawing.
If Not m_Drawing Then Exit Sub
m_Drawing = False

' Save the new point.
m_X2 = e.X
m_Y2 = e.Y

' Draw the new line permanently on the buffer.
m_BufferGraphics.DrawLine( _
Pens.Blue, m_X1, m_Y1, m_X2, m_Y2)

' Redraw to show the new line.
DrawForm(Me.CreateGraphics())
End Sub

' Redraw the form.
Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
DrawForm(e.Graphics)
End Sub


hope it work for you,
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mohd40 is offline Offline
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Oct 17th, 2009
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israr

Click to Expand / Collapse  Quote originally posted by gminhas ...
hi guys!
can anyone tell me now to draw a line in VB.NET form?
I've been trying to do so , but nothings coming..
hi i am php developer.if did't know such about .net.if u help me in php
then reply me
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israrkhan is offline Offline
2 posts
since Oct 2009

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.
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