Writing a DrawToBitmap function for the RichTextBox control

[Technical]

Greetings,

I am currently working on a project that requires that the contents of
a RichTextBox control be drawn to a bitmap. I have attempted nearly
everything including using calls into the Win32 API BitBlt function. Is
t here a way to perform this feat without sifting through the contents
of the control and drawing character-by-character? (Note that I have
seen just about every forum message on the web regarding this topic,
and have attempt many different approaches: PrintWindow, overloads,
etc...)

Thanks for your help

[DeveloperX]

Assuming you're only interested in the visible bit, it's easy with
interop. There's also a way to blit in dotnet, but I can't find where
ever I saw it.

using System.Runtime. InteropServices ;

[DllImport("gdi3 2.dll")]
static extern bool BitBlt(IntPtr hdc, int nXDest, int nYDest, int
nWidth,
int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, uint dwRop);

Got a form with a rtb and this creates a copy into a picturebox. You
might have to tweak it a bit, but the basics are there.

Graphics g = richTextBox1.Cr eateGraphics();
Graphics g2 = pictureBox1.Cre ateGraphics();
IntPtr gi = g.GetHdc();
IntPtr gi2 = g2.GetHdc();
BitBlt(gi2,0,0, pictureBox1.Wid th,pictureBox1. Height,gi,0,0,0 x00CC0020);
g.Dispose();
g2.Dispose();

sorry I've not got more time to look into it.

Technical wrote:

Greetings,

I am currently working on a project that requires that the contents of
a RichTextBox control be drawn to a bitmap. I have attempted nearly
everything including using calls into the Win32 API BitBlt function. Is
t here a way to perform this feat without sifting through the contents
of the control and drawing character-by-character? (Note that I have
seen just about every forum message on the web regarding this topic,
and have attempt many different approaches: PrintWindow, overloads,
etc...)

Thanks for your help

[DeveloperX]

Oops replace the bitblt line with

BitBlt(gi2,0,0, richTextBox1.Wi dth,richTextBox 1.Height,gi,0,0 ,0x00CC0020);

btw the oocc0020 refers to copy.

There are some issues with releasing (disposing) the Graphics objects
which I haven't looked into, but that should be an easier to sort out.

DeveloperX wrote:

Assuming you're only interested in the visible bit, it's easy with
interop. There's also a way to blit in dotnet, but I can't find where
ever I saw it.

using System.Runtime. InteropServices ;

[DllImport("gdi3 2.dll")]
static extern bool BitBlt(IntPtr hdc, int nXDest, int nYDest, int
nWidth,
int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, uint dwRop);

Got a form with a rtb and this creates a copy into a picturebox. You
might have to tweak it a bit, but the basics are there.

Graphics g = richTextBox1.Cr eateGraphics();
Graphics g2 = pictureBox1.Cre ateGraphics();
IntPtr gi = g.GetHdc();
IntPtr gi2 = g2.GetHdc();
BitBlt(gi2,0,0, pictureBox1.Wid th,pictureBox1. Height,gi,0,0,0 x00CC0020);
g.Dispose();
g2.Dispose();

sorry I've not got more time to look into it.

Technical wrote:

Greetings,

I am currently working on a project that requires that the contents of
a RichTextBox control be drawn to a bitmap. I have attempted nearly
everything including using calls into the Win32 API BitBlt function. Is
t here a way to perform this feat without sifting through the contents
of the control and drawing character-by-character? (Note that I have
seen just about every forum message on the web regarding this topic,
and have attempt many different approaches: PrintWindow, overloads,
etc...)

Thanks for your help

[DeveloperX]

Ok, I wasn't a million miles off, Bob Powell gives us the answer at
http://www.bobpowell.net/capture.htm
Here's his code, GetDC and ReleaseDC are imported along with BitBlt.

System.IntPtr srcDC=GetDC(thi s.pictureBox1.H andle);
Bitmap bm=new
Bitmap(this.pic tureBox1.Width, this.pictureBox 1.Height);
Graphics g=Graphics.From Image(bm);
System.IntPtr bmDC=g.GetHdc() ;
BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,srcDC,0,0, 0x00CC0020
/*SRCCOPY*/);
ReleaseDC(this. pictureBox1.Han dle, srcDC);
g.ReleaseHdc(bm DC);
g.Dispose();

DeveloperX wrote:

Oops replace the bitblt line with

BitBlt(gi2,0,0, richTextBox1.Wi dth,richTextBox 1.Height,gi,0,0 ,0x00CC0020);

btw the oocc0020 refers to copy.

There are some issues with releasing (disposing) the Graphics objects
which I haven't looked into, but that should be an easier to sort out.

DeveloperX wrote:

Assuming you're only interested in the visible bit, it's easy with
interop. There's also a way to blit in dotnet, but I can't find where
ever I saw it.

using System.Runtime. InteropServices ;

[DllImport("gdi3 2.dll")]
static extern bool BitBlt(IntPtr hdc, int nXDest, int nYDest, int
nWidth,
int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, uint dwRop);

Got a form with a rtb and this creates a copy into a picturebox. You
might have to tweak it a bit, but the basics are there.

Graphics g = richTextBox1.Cr eateGraphics();
Graphics g2 = pictureBox1.Cre ateGraphics();
IntPtr gi = g.GetHdc();
IntPtr gi2 = g2.GetHdc();
BitBlt(gi2,0,0, pictureBox1.Wid th,pictureBox1. Height,gi,0,0,0 x00CC0020);
g.Dispose();
g2.Dispose();

sorry I've not got more time to look into it.

Technical wrote:

Greetings,
>
I am currently working on a project that requires that the contents of
a RichTextBox control be drawn to a bitmap. I have attempted nearly
everything including using calls into the Win32 API BitBlt function. Is
t here a way to perform this feat without sifting through the contents
of the control and drawing character-by-character? (Note that I have
seen just about every forum message on the web regarding this topic,
and have attempt many different approaches: PrintWindow, overloads,
etc...)
>
Thanks for your help

[Technical]

DeveloperX,

Thanks for the help! I finally got that implementation to work. Thanks
for your help.
DeveloperX wrote:

Ok, I wasn't a million miles off, Bob Powell gives us the answer at
http://www.bobpowell.net/capture.htm
Here's his code, GetDC and ReleaseDC are imported along with BitBlt.

System.IntPtr srcDC=GetDC(thi s.pictureBox1.H andle);
Bitmap bm=new
Bitmap(this.pic tureBox1.Width, this.pictureBox 1.Height);
Graphics g=Graphics.From Image(bm);
System.IntPtr bmDC=g.GetHdc() ;
BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,srcDC,0,0, 0x00CC0020
/*SRCCOPY*/);
ReleaseDC(this. pictureBox1.Han dle, srcDC);
g.ReleaseHdc(bm DC);
g.Dispose();

DeveloperX wrote:

Oops replace the bitblt line with

BitBlt(gi2,0,0, richTextBox1.Wi dth,richTextBox 1.Height,gi,0,0 ,0x00CC0020);

btw the oocc0020 refers to copy.

There are some issues with releasing (disposing) the Graphics objects
which I haven't looked into, but that should be an easier to sort out.

DeveloperX wrote:

Assuming you're only interested in the visible bit, it's easy with
interop. There's also a way to blit in dotnet, but I can't find where
ever I saw it.
>
using System.Runtime. InteropServices ;
>
[DllImport("gdi3 2.dll")]
static extern bool BitBlt(IntPtr hdc, int nXDest, int nYDest, int
nWidth,
int nHeight, IntPtr hdcSrc, int nXSrc, int nYSrc, uint dwRop);
>
Got a form with a rtb and this creates a copy into a picturebox. You
might have to tweak it a bit, but the basics are there.
>
Graphics g = richTextBox1.Cr eateGraphics();
Graphics g2 = pictureBox1.Cre ateGraphics();
IntPtr gi = g.GetHdc();
IntPtr gi2 = g2.GetHdc();
BitBlt(gi2,0,0, pictureBox1.Wid th,pictureBox1. Height,gi,0,0,0 x00CC0020);
g.Dispose();
g2.Dispose();
>
sorry I've not got more time to look into it.
>
>
>
Technical wrote:
Greetings,

I am currently working on a project that requires that the contents of
a RichTextBox control be drawn to a bitmap. I have attempted nearly
everything including using calls into the Win32 API BitBlt function. Is
t here a way to perform this feat without sifting through the contents
of the control and drawing character-by-character? (Note that I have
seen just about every forum message on the web regarding this topic,
and have attempt many different approaches: PrintWindow, overloads,
etc...)

Thanks for your help