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How to draw a thick arrow in picturebox
Posted: Mon Oct 14, 2013 11:31 am
by polas
Hello I have here a problem with drawing on the picture.
Draw a picture on well but it's drawing a thin line and I need a thicker thickness of at least 4.5.
But I'd like to draw arrow and not line.
Need a simple arrows with no gradient and a much smaller and thinner.
Approximately 4.5 thickness used on the image.
Here's an example of what I need.
how do i do that ?
So far, I have only this code.
Here is the code:
Code: Select all Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
If _Previous IsNot Nothing Then
If PictureBox1.Image Is Nothing Then
Dim bmp As New Bitmap(PictureBox1.Width, PictureBox1.Height)
Using g As Graphics = Graphics.FromImage(bmp)
g.Clear(Color.White)
End Using
PictureBox1.Image = bmp
End If
Using g As Graphics = Graphics.FromImage(PictureBox1.Image)
g.DrawLine(Pens.Red, _Previous.Value, e.Location)
End Using
PictureBox1.Invalidate()
_Previous = e.Location
End If
End Sub
Private _Previous As System.Nullable(Of Point) = Nothing
Private Sub pictureBox1_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) Handles PictureBox1.MouseDown
_Previous = e.Location
PictureBox1_MouseMove(sender, e)
End Sub
Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
_Previous = Nothing
End Sub
Any help would benefit me.
Re: How to draw a thick arrow in picturebox in vb.net
Posted: Mon Oct 14, 2013 2:14 pm
by Dummy1912
Hello,
you can use this to draw a arrow
This will draw a arrow on the picturebox
Code: Select allPrivate Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
b = New Bitmap(PictureBox1.Image)
e.Graphics. = Graphics.FromImage(b)
e.Graphics.DrawLine(Pens.Yellow, 100, 10, 110, 20)
e.Graphics.DrawLine(Pens.Yellow, 110, 20, 100, 30)
e.Graphics.DrawLine(Pens.Yellow, 90, 20, 110, 20)
PictureBox1.Image = b
e.Graphics.Dispose()
End Sub
Re: How to draw a thick arrow in picturebox
Posted: Mon Oct 14, 2013 5:02 pm
by polas
How to use it cuz b is not declarated
Re: How to draw a thick arrow in picturebox
Posted: Mon Oct 14, 2013 7:10 pm
by Filip
Try adding following code in first line after sub declatation:
I haven't been programming VB in a while now but I think this should work
Hope it helps!
-Filip
Re: How to draw a thick arrow in picturebox
Posted: Tue Oct 15, 2013 5:25 pm
by polas
still got error
e.Graphics. = Graphics.FromImage(b)
Re: How to draw a thick arrow in picturebox
Posted: Tue Oct 15, 2013 7:02 pm
by Filip
Can you paste the error which are you getting?
Re: How to draw a thick arrow in picturebox
Posted: Wed Oct 16, 2013 10:02 am
by polas
Here is where the error is
Code: Select alle.Graphics. = Graphics.FromImage(b)
Re: How to draw a thick arrow in picturebox
Posted: Sat Oct 19, 2013 4:31 pm
by mandai
You can use this code to draw the arrow by mouse click:
Code: Select all Dim g As Graphics
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
PictureBox1.Image = New Bitmap(PictureBox1.Width, PictureBox1.Height)
g = Graphics.FromImage(PictureBox1.Image)
End Sub
Sub drawArrow(ByVal location As PointF, ByVal scale As Single)
Dim points(8 - 1) As PointF
points(0) = location
points(1) = New PointF(location.X + (scale * 2), location.Y - (scale * 1.5))
points(2) = New PointF(points(1).X, points(1).Y + scale)
points(3) = New PointF(points(2).X + (scale * 2), points(2).Y)
points(4) = New PointF(points(3).X, points(3).Y + scale)
points(5) = New PointF(points(4).X - (scale * 2), points(4).Y)
points(6) = New PointF(points(5).X, points(5).Y + scale)
points(7) = location
Dim pathTypes(points.Length - 1) As Byte
For i As Integer = 0 To pathTypes.Length - 1
pathTypes(i) = Drawing2D.PathPointType.Line
Next
Dim gp As Drawing2D.GraphicsPath = New Drawing2D.GraphicsPath(points, pathTypes)
g.FillPath(Brushes.Red, gp)
End Sub
Private Sub PictureBox1_MouseUp(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
Dim location As PointF = New PointF(e.X, e.Y)
Dim scale As Single = 30
drawArrow(location, scale)
PictureBox1.Refresh()
End Sub
The scale can also be adjusted.