How to save to a bitmap?

[Lee]

I have the following code
using System;
using System.Windows. Forms;
using System.Drawing;
using System.Collecti ons;
namespace FINN
{

public class flickerFreePict ureBox : PictureBox
{
public ArrayList Lines = new ArrayList();
public flickerFreePict ureBox()
{

this.SetStyle(C ontrolStyles.Do ubleBuffer, true);
this.SetStyle (ControlStyles. AllPaintingInWm Paint, true);
this.SetStyle(C ontrolStyles.Us erPaint, true);
this.SetStyle(C ontrolStyles.Re sizeRedraw, true);
//this.MouseMove += new MouseEventHandl er(_MouseMove);
}
protected override void OnPaint(PaintEv entArgs e)
{
bool error = false;
//e.Graphics.Smoo thingMode = SmoothingMode.A ntiAlias;
try
{
foreach(scribbl eObject al in Lines)
{
bool Drawdot = false;
try
{
Point[] linelist = new Point[
al.linePosition s.Count];

al.linePosition s.CopyTo(0,line list,0,al.lineP ositions.Count) ;
e.Graphics.Draw Lines(al.pen(), linelist);
}
catch
{
Drawdot = true; //we want to draw a dot
}
if(Drawdot)
{
//Draw a single dot as the user has only
clicked, rather than clicked and dragged
//TODO: Draw a dot
}

}
}
catch
{
error = true;
}
if(error)
{
//this.OnPaint(e) ;
}
}
}

}

And I would like to be able to create a bitmap of what gets drawn in
OnPaint so that I can save it to file, I've tried a few things, but so
far just ended up with black bitmaps the same size as the control that
code creates, any suggestions or code snippets would be a great help.

Cheers

Lee

[Morten Wennevik]

Hi Lee

Before Bob Powell notices you are using a PictureBox for drawing, you
should read the GDI+ FAQ. Specifically the article regarding PictureBox

http://www.bobpowell.net/pictureboxhowto.htm

As for saving the Bitmap you could inside your Paint procedure separate
actual drawing to a method that you pass either the Paint graphics object,
or a Bitmap graphics object, otherwise refer to the FAQ

--
Happy Coding!
Morten Wennevik [C# MVP]

[Lee]

I've done the following

In OnPaint added this

Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);

Then for my painting method, simply duplicated it so that it paints to
g as well.
Now I get a nice black bitmap and not a lot else :(

Thanks for the link to the FAQ but I'm not sure how I can refactor my
current code to make use of it, due to deadlines I think it might have
to wait for the next project.

Cheers

Morten Wennevik wrote:

Hi Lee

Before Bob Powell notices you are using a PictureBox for drawing, you
should read the GDI+ FAQ. Specifically the article regarding PictureBox

http://www.bobpowell.net/pictureboxhowto.htm

As for saving the Bitmap you could inside your Paint procedure separate
actual drawing to a method that you pass either the Paint graphics object,
or a Bitmap graphics object, otherwise refer to the FAQ

--
Happy Coding!
Morten Wennevik [C# MVP]

[Simon Tamman]

Graphics g = Graphics.FromIm age(bmp);

The above line is good.
Therefore do you then do all of the drawing with THAT graphics object?
Then after the drawing has finished save the bitmap (bmp) to disk?

That (from what I recall) should do the trick.

Simon Tamman

"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .

I've done the following

In OnPaint added this

Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);

Then for my painting method, simply duplicated it so that it paints to
g as well.
Now I get a nice black bitmap and not a lot else :(

Thanks for the link to the FAQ but I'm not sure how I can refactor my
current code to make use of it, due to deadlines I think it might have
to wait for the next project.

Cheers

Morten Wennevik wrote:

Hi Lee

Before Bob Powell notices you are using a PictureBox for drawing, you
should read the GDI+ FAQ. Specifically the article regarding PictureBox

http://www.bobpowell.net/pictureboxhowto.htm

As for saving the Bitmap you could inside your Paint procedure separate
actual drawing to a method that you pass either the Paint graphics

object,

or a Bitmap graphics object, otherwise refer to the FAQ

--
Happy Coding!
Morten Wennevik [C# MVP]

[Lee]

Yep that is exactly what I'm doing, but all I get back is a black
bitmap.

I've tried also: Graphics g = Graphics.FromIm age(this.Image) ;

which yeilds the same results

Simon Tamman wrote:

Graphics g = Graphics.FromIm age(bmp);

The above line is good.
Therefore do you then do all of the drawing with THAT graphics object?
Then after the drawing has finished save the bitmap (bmp) to disk?

That (from what I recall) should do the trick.

Simon Tamman

"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .

I've done the following

In OnPaint added this

Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);

Then for my painting method, simply duplicated it so that it paints to
g as well.
Now I get a nice black bitmap and not a lot else :(

Thanks for the link to the FAQ but I'm not sure how I can refactor my
current code to make use of it, due to deadlines I think it might have
to wait for the next project.

Cheers

Morten Wennevik wrote:

Hi Lee
>
Before Bob Powell notices you are using a PictureBox for drawing, you
should read the GDI+ FAQ. Specifically the article regarding PictureBox
>
http://www.bobpowell.net/pictureboxhowto.htm
>
As for saving the Bitmap you could inside your Paint procedure separate
actual drawing to a method that you pass either the Paint graphics

object,

or a Bitmap graphics object, otherwise refer to the FAQ
>
--
Happy Coding!
Morten Wennevik [C# MVP]

[Lee]

Got it working, here is the entire code
using System;
using System.Windows. Forms;
using System.Drawing;
using System.Collecti ons;
namespace FINN
{

public class flickerFreePict ureBox : PictureBox
{
public ArrayList Lines = new ArrayList();
public Bitmap bmp;
private Graphics g;
public flickerFreePict ureBox()
{
bmp = new Bitmap(800, 310);
g = Graphics.FromIm age(bmp);
g.FillRectangle (System.Drawing .Brushes.White, 0,0, 800, 310);
this.SetStyle(C ontrolStyles.Do ubleBuffer, true);
this.SetStyle(C ontrolStyles.Al lPaintingInWmPa int, true);
this.SetStyle(C ontrolStyles.Us erPaint, true);
this.SetStyle(C ontrolStyles.Re sizeRedraw, true);
//this.MouseMove += new MouseEventHandl er(_MouseMove);

}
protected override void OnPaint(PaintEv entArgs e)
{
bool error = false;

//e.Graphics.Smoo thingMode = SmoothingMode.A ntiAlias;
try
{
foreach(scribbl eObject al in Lines)
{
bool Drawdot = false;
try
{
Point[] linelist = new Point[al.linePosition s.Count];
al.linePosition s.CopyTo(0,line list,0,al.lineP ositions.Count) ;

e.Graphics.Draw Lines(al.pen(), linelist);
g.DrawLines(al. pen(), linelist);

}
catch
{
Drawdot = true; //we want to draw a dot
}
if(Drawdot)
{
//Draw a single dot as the user has only clicked, rather than
clicked and dragged
//TODO: Draw a dot
}
}
}
catch
{
error = true;
}
if(error)
{
//this.OnPaint(e) ;
}
bmp.Save("Test. bmp");

}
}

}
I know there are magic numbers in there, but for some reason
'this.Width' etc wasn't working when I tried it on the setup, got too
many other things to do to refine it, but if I get some time I'll make
it neater, cheers for your help all
Lee wrote:

Yep that is exactly what I'm doing, but all I get back is a black
bitmap.

I've tried also: Graphics g = Graphics.FromIm age(this.Image) ;

which yeilds the same results

Simon Tamman wrote:

Graphics g = Graphics.FromIm age(bmp);

The above line is good.
Therefore do you then do all of the drawing with THAT graphics object?
Then after the drawing has finished save the bitmap (bmp) to disk?

That (from what I recall) should do the trick.

Simon Tamman

"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .

I've done the following
>
In OnPaint added this
>
Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);
>
Then for my painting method, simply duplicated it so that it paints to
g as well.
Now I get a nice black bitmap and not a lot else :(
>
Thanks for the link to the FAQ but I'm not sure how I can refactor my
current code to make use of it, due to deadlines I think it might have
to wait for the next project.
>
Cheers
>
Morten Wennevik wrote:
Hi Lee

Before Bob Powell notices you are using a PictureBox for drawing, you
should read the GDI+ FAQ. Specifically the article regarding PictureBox

http://www.bobpowell.net/pictureboxhowto.htm

As for saving the Bitmap you could inside your Paint procedure separate
actual drawing to a method that you pass either the Paint graphics

object,

or a Bitmap graphics object, otherwise refer to the FAQ

--
Happy Coding!
Morten Wennevik [C# MVP]
>

[Simon Tamman]

Eh?

Open a new windows project, drop a picture box onto the form and paste the
following code in.
That should work.
This code not only saves the file to disk (c:\test.bmp) but also reloads it
from disk to the picturebox and works fine for me.

Then track back from this code onto your code and see where you're going
wrong.

private string path = "c:\\test.b mp";

public Form1()
{
InitializeCompo nent();
this.Load += new EventHandler(Fo rm1_Load);
}

void Form1_Load(obje ct sender, EventArgs e)
{
using (Bitmap b = new Bitmap(100, 100))
{
using (Graphics g = Graphics.FromIm age(b))
{
using (SolidBrush sb = new SolidBrush(Colo r.Red))
{
g.FillRectangle (sb, 0, 0, 50, 50);
}
using (SolidBrush sb = new SolidBrush(Colo r.Green))
{
g.FillRectangle (sb, 50, 50, 50, 50);
}
b.Save(path, System.Drawing. Imaging.ImageFo rmat.Bmp);
}
}
LoadBitmap();
}

private void LoadBitmap()
{
Bitmap b = (Bitmap)Bitmap. FromFile(path);
this.pictureBox 1.Image = b;
}

"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ m73g2000cwd.goo glegroups.com.. .

Yep that is exactly what I'm doing, but all I get back is a black
bitmap.

I've tried also: Graphics g = Graphics.FromIm age(this.Image) ;

which yeilds the same results

Simon Tamman wrote:

Graphics g = Graphics.FromIm age(bmp);

The above line is good.
Therefore do you then do all of the drawing with THAT graphics object?
Then after the drawing has finished save the bitmap (bmp) to disk?

That (from what I recall) should do the trick.

Simon Tamman

"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .

I've done the following
>
In OnPaint added this
>
Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);
>
Then for my painting method, simply duplicated it so that it paints to
g as well.
Now I get a nice black bitmap and not a lot else :(
>
Thanks for the link to the FAQ but I'm not sure how I can refactor my
current code to make use of it, due to deadlines I think it might have
to wait for the next project.
>
Cheers
>
Morten Wennevik wrote:
Hi Lee

Before Bob Powell notices you are using a PictureBox for drawing,

you

should read the GDI+ FAQ. Specifically the article regarding

PictureBox

http://www.bobpowell.net/pictureboxhowto.htm

As for saving the Bitmap you could inside your Paint procedure

separate

actual drawing to a method that you pass either the Paint graphics

object,

or a Bitmap graphics object, otherwise refer to the FAQ

--
Happy Coding!
Morten Wennevik [C# MVP]
>

[Simon Tamman]

Glad to hear you got it working.
I'd re-iterate Morten's advice, Bob Powells GDI+ FAQ is a great FAQ to read
on this kind of thing.

Additionally i'd watch out for the way you're performing the painting the
segment, performing a try catch to determine the user's action is a BAD way
to work things out you'd be better off working out what the user did without
using exceptions.
Secondly I know you currently have it commented out but calling OnPaint
within OnPaint is scary recursion which will lead you into the badness of
StackOverflowEx ceptions.

I'd recommend reading:
http://www.amazon.co.uk/Framework-De.../dp/0321246756
for a better understanding of exception handling (it has an excellent
chapter on it), it's also a pretty good book for plenty of other reasons.

HTH

Simon
"Lee" <lv******@gmail .comwrote in message
news:11******** *************@e 3g2000cwe.googl egroups.com...

Got it working, here is the entire code
using System;
using System.Windows. Forms;
using System.Drawing;
using System.Collecti ons;
namespace FINN
{

public class flickerFreePict ureBox : PictureBox
{
public ArrayList Lines = new ArrayList();
public Bitmap bmp;
private Graphics g;
public flickerFreePict ureBox()
{
bmp = new Bitmap(800, 310);
g = Graphics.FromIm age(bmp);
g.FillRectangle (System.Drawing .Brushes.White, 0,0, 800, 310);
this.SetStyle(C ontrolStyles.Do ubleBuffer, true);
this.SetStyle(C ontrolStyles.Al lPaintingInWmPa int, true);
this.SetStyle(C ontrolStyles.Us erPaint, true);
this.SetStyle(C ontrolStyles.Re sizeRedraw, true);
//this.MouseMove += new MouseEventHandl er(_MouseMove);

}
protected override void OnPaint(PaintEv entArgs e)
{
bool error = false;

//e.Graphics.Smoo thingMode = SmoothingMode.A ntiAlias;
try
{
foreach(scribbl eObject al in Lines)
{
bool Drawdot = false;
try
{
Point[] linelist = new Point[al.linePosition s.Count];
al.linePosition s.CopyTo(0,line list,0,al.lineP ositions.Count) ;

e.Graphics.Draw Lines(al.pen(), linelist);
g.DrawLines(al. pen(), linelist);

}
catch
{
Drawdot = true; //we want to draw a dot
}
if(Drawdot)
{
//Draw a single dot as the user has only clicked, rather than
clicked and dragged
//TODO: Draw a dot
}
}
}
catch
{
error = true;
}
if(error)
{
//this.OnPaint(e) ;
}
bmp.Save("Test. bmp");

}
}

}
I know there are magic numbers in there, but for some reason
'this.Width' etc wasn't working when I tried it on the setup, got too
many other things to do to refine it, but if I get some time I'll make
it neater, cheers for your help all
Lee wrote:

Yep that is exactly what I'm doing, but all I get back is a black
bitmap.

I've tried also: Graphics g = Graphics.FromIm age(this.Image) ;

which yeilds the same results

Simon Tamman wrote:

Graphics g = Graphics.FromIm age(bmp);
>
The above line is good.
Therefore do you then do all of the drawing with THAT graphics object?
Then after the drawing has finished save the bitmap (bmp) to disk?
>
That (from what I recall) should do the trick.
>
Simon Tamman
>
"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .
I've done the following

In OnPaint added this

Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);

Then for my painting method, simply duplicated it so that it paints

to

g as well.
Now I get a nice black bitmap and not a lot else :(

Thanks for the link to the FAQ but I'm not sure how I can refactor

my

current code to make use of it, due to deadlines I think it might

have

to wait for the next project.

Cheers

Morten Wennevik wrote:
Hi Lee
>
Before Bob Powell notices you are using a PictureBox for drawing,

you

should read the GDI+ FAQ. Specifically the article regarding

PictureBox

>
http://www.bobpowell.net/pictureboxhowto.htm
>
As for saving the Bitmap you could inside your Paint procedure

separate

actual drawing to a method that you pass either the Paint graphics
object,
or a Bitmap graphics object, otherwise refer to the FAQ
>
--
Happy Coding!
Morten Wennevik [C# MVP]

[Lee]

OnPaint is commented out for exactly that reason! :-)

I agree with you on the try/catch.

I'm fully aware that the code is a horrible hack, it was written months
ago and was my first real attempt and dealing with System.Drawing et
al. Unfortunately deadlines loom and I don't have time to refactor
it...

The moral of the story: get it right the first time.

Simon Tamman wrote:

Glad to hear you got it working.
I'd re-iterate Morten's advice, Bob Powells GDI+ FAQ is a great FAQ to read
on this kind of thing.

Additionally i'd watch out for the way you're performing the painting the
segment, performing a try catch to determine the user's action is a BAD way
to work things out you'd be better off working out what the user did without
using exceptions.
Secondly I know you currently have it commented out but calling OnPaint
within OnPaint is scary recursion which will lead you into the badness of
StackOverflowEx ceptions.

I'd recommend reading:
http://www.amazon.co.uk/Framework-De.../dp/0321246756
for a better understanding of exception handling (it has an excellent
chapter on it), it's also a pretty good book for plenty of other reasons.

HTH

Simon
"Lee" <lv******@gmail .comwrote in message
news:11******** *************@e 3g2000cwe.googl egroups.com...

Got it working, here is the entire code
using System;
using System.Windows. Forms;
using System.Drawing;
using System.Collecti ons;
namespace FINN
{

public class flickerFreePict ureBox : PictureBox
{
public ArrayList Lines = new ArrayList();
public Bitmap bmp;
private Graphics g;
public flickerFreePict ureBox()
{
bmp = new Bitmap(800, 310);
g = Graphics.FromIm age(bmp);
g.FillRectangle (System.Drawing .Brushes.White, 0,0, 800, 310);
this.SetStyle(C ontrolStyles.Do ubleBuffer, true);
this.SetStyle(C ontrolStyles.Al lPaintingInWmPa int, true);
this.SetStyle(C ontrolStyles.Us erPaint, true);
this.SetStyle(C ontrolStyles.Re sizeRedraw, true);
//this.MouseMove += new MouseEventHandl er(_MouseMove);

}
protected override void OnPaint(PaintEv entArgs e)
{
bool error = false;

//e.Graphics.Smoo thingMode = SmoothingMode.A ntiAlias;
try
{
foreach(scribbl eObject al in Lines)
{
bool Drawdot = false;
try
{
Point[] linelist = new Point[al.linePosition s.Count];
al.linePosition s.CopyTo(0,line list,0,al.lineP ositions.Count) ;

e.Graphics.Draw Lines(al.pen(), linelist);
g.DrawLines(al. pen(), linelist);

}
catch
{
Drawdot = true; //we want to draw a dot
}
if(Drawdot)
{
//Draw a single dot as the user has only clicked, rather than
clicked and dragged
//TODO: Draw a dot
}
}
}
catch
{
error = true;
}
if(error)
{
//this.OnPaint(e) ;
}
bmp.Save("Test. bmp");

}
}

}
I know there are magic numbers in there, but for some reason
'this.Width' etc wasn't working when I tried it on the setup, got too
many other things to do to refine it, but if I get some time I'll make
it neater, cheers for your help all
Lee wrote:

Yep that is exactly what I'm doing, but all I get back is a black
bitmap.
>
I've tried also: Graphics g = Graphics.FromIm age(this.Image) ;
>
which yeilds the same results
>
Simon Tamman wrote:
Graphics g = Graphics.FromIm age(bmp);

The above line is good.
Therefore do you then do all of the drawing with THAT graphics object?
Then after the drawing has finished save the bitmap (bmp) to disk?

That (from what I recall) should do the trick.

Simon Tamman

"Lee" <lv******@gmail .comwrote in message
news:11******** **************@ b28g2000cwb.goo glegroups.com.. .
I've done the following
>
In OnPaint added this
>
Bitmap bmp = new Bitmap(this.Wid th, this.Height);
Graphics g = Graphics.FromIm age(bmp);
>
Then for my painting method, simply duplicated it so that it paints

to

g as well.
Now I get a nice black bitmap and not a lot else :(
>
Thanks for the link to the FAQ but I'm not sure how I can refactor

my

current code to make use of it, due to deadlines I think it might

have

to wait for the next project.
>
Cheers
>
Morten Wennevik wrote:
Hi Lee

Before Bob Powell notices you are using a PictureBox for drawing,

you

should read the GDI+ FAQ. Specifically the article regarding

PictureBox

http://www.bobpowell.net/pictureboxhowto.htm

As for saving the Bitmap you could inside your Paint procedure

separate

actual drawing to a method that you pass either the Paint graphics
object,
or a Bitmap graphics object, otherwise refer to the FAQ

--
Happy Coding!
Morten Wennevik [C# MVP]
>

[Tim Van Wassenhove]

On 2006-10-24, Lee <lv******@gmail .comwrote:

public class flickerFreePict ureBox : PictureBox

Assuming you have an instance named myFlickerFreePi ctureBox:

int width = myFlickerFreePi ctureBox.Width;
int height = myFlickerFreePi ctureBox.Height ;

Bitmap bitmap = new Bitmap(width, height);
myFlickerFreePi ctureBox.DrawTo Bitmap(bitmap, new Rectangle(0, 0, width, height));

bitmap.Save(@"C :\somewhere.gif ", ImageFormat.Gif );
--
Met vriendelijke groeten,
Tim Van Wassenhove <http://www.timvw.be>