Save lines drawn in the picturebox as an lmage

[Yash]

Have used DrawLine() method to draw some lines in the picturebox (sort
of a barcode) in the picturebox paint event.
This diagram has to be saved as an image in bmp or tiff format.
But the problem is that these lines are not recognized as the image of
the picturebox.
It shows picturebox.image = nothing.

How do we convert these lines drawn as the image of the picturebox so
that it can be saved.

Thanks for any help.

 

[Peter Proost]

Hi, you need to draw to a bitmap's Graphics object:

Dim b As Bitmap = New Bitmap(100,100)
Dim g As Graphics = Graphics.FromImage(b)

g.DrawLine(Pens.Black, 5,5,50,5)
g.Dispose()

picturebox1.image = b
b.Save(...)

Greetz Peter

 

[Yash]

Thanks Peter
The saving part is working perfectly.
The preview also shows the image properly.

But there's another problem
The image contains Black and colored lines.
So if we open this image in Paint to change some colors,
the background shown is black -- which hides the black lines totally.

I tried Bitmap.MakeTransparent but still the same.
The image is transparent but still the background is black.
Is this a .NET problem or Paint problem.
Any idea how to change this.

 

[Peter Proost]

Hi,

add
g.Clear(Color.White) before g.DrawLine(Pens.Black, 5,5,50,5)
this clears the drawing surface and should do the trick for you

Greetz Peter

 

[Herfried K. Wagner [MVP]]

Have used DrawLine() method to draw some lines in the picturebox (sort
of a barcode) in the picturebox paint event.
This diagram has to be saved as an image in bmp or tiff format.

<URL:http://www.dotnetrix.co.uk/misc.html>
-> "Save the Image currently displayed in a PictureBox."