GDI+ problem

[Pohihihi]

I am getting a generic GDI+ error on following code. Basically it is trying
to capture screen image and save in a file.
Is there a way to find more details on this error? Thanks for the help.

---------------------------
ERROR MSG
---------------------------
System.Runtime. InteropServices .ExternalExcept ion: A generic error occurred
in GDI+.
at System.Drawing. Image.Save(Stri ng filename, ImageCodecInfo encoder,
EncoderParamete rs encoderParams)
at System.Drawing. Image.Save(Stri ng filename, ImageFormat format)
at ScreenCapture.F orm1.TakeSnapNo w() in c:\visual studio
projects\screen capture\form1.c s:line 102

Sorry for the formating below.

//First, you need to import the BitBlt, GetDC and ReleaseDC functions.

//imports the GDI BitBlt function that enables the background of the window

//to be captured

[DllImport("gdi3 2.dll")]

private static extern bool BitBlt(

IntPtr hdcDest, // handle to destination DC

int nXDest, // x-coord of destination upper-left corner

int nYDest, // y-coord of destination upper-left corner

int nWidth, // width of destination rectangle

int nHeight, // height of destination rectangle

IntPtr hdcSrc, // handle to source DC

int nXSrc, // x-coordinate of source upper-left corner

int nYSrc, // y-coordinate of source upper-left corner

System.Int32 dwRop // raster operation code

);
[DllImport("User 32.dll")]

public extern static System.IntPtr GetDC(System.In tPtr hWnd);

[DllImport("User 32.dll")]

public extern static int ReleaseDC(Syste m.IntPtr hWnd, System.IntPtr hDC);
//modified to include hWnd
//Now, to capture the screen in it's entirety you can do the following.

public void TakeSnapNow()

{

System.IntPtr desktopDC=GetDC (System.IntPtr. Zero);

Bitmap bm=new Bitmap(SystemIn formation.Virtu alScreen.Width,
SystemInformati on.VirtualScree n.Height);

try

{

Graphics g=Graphics.From Image(bm);

System.IntPtr bmDC=g.GetHdc() ;

BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,desktopDC, 0,0,0x00CC0020 /*SRCCOPY*/);

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

ReleaseDC(Syste m.IntPtr.Zero, desktopDC);

g.ReleaseHdc(bm DC);

g.Dispose();

}

catch(Exception er)

{

MessageBox.Show (er.ToString()) ;

}

}

[Mark R. Dawson]

"Pohihihi" wrote:

I am getting a generic GDI+ error on following code. Basically it is trying
to capture screen image and save in a file.
Is there a way to find more details on this error? Thanks for the help.

---------------------------
ERROR MSG
---------------------------
System.Runtime. InteropServices .ExternalExcept ion: A generic error occurred
in GDI+.
at System.Drawing. Image.Save(Stri ng filename, ImageCodecInfo encoder,
EncoderParamete rs encoderParams)
at System.Drawing. Image.Save(Stri ng filename, ImageFormat format)
at ScreenCapture.F orm1.TakeSnapNo w() in c:\visual studio
projects\screen capture\form1.c s:line 102

Sorry for the formating below.

//First, you need to import the BitBlt, GetDC and ReleaseDC functions.

//imports the GDI BitBlt function that enables the background of the window

//to be captured

[DllImport("gdi3 2.dll")]

private static extern bool BitBlt(

IntPtr hdcDest, // handle to destination DC

int nXDest, // x-coord of destination upper-left corner

int nYDest, // y-coord of destination upper-left corner

int nWidth, // width of destination rectangle

int nHeight, // height of destination rectangle

IntPtr hdcSrc, // handle to source DC

int nXSrc, // x-coordinate of source upper-left corner

int nYSrc, // y-coordinate of source upper-left corner

System.Int32 dwRop // raster operation code

);
[DllImport("User 32.dll")]

public extern static System.IntPtr GetDC(System.In tPtr hWnd);

[DllImport("User 32.dll")]

public extern static int ReleaseDC(Syste m.IntPtr hWnd, System.IntPtr hDC);
//modified to include hWnd
//Now, to capture the screen in it's entirety you can do the following.

public void TakeSnapNow()

{

System.IntPtr desktopDC=GetDC (System.IntPtr. Zero);

Bitmap bm=new Bitmap(SystemIn formation.Virtu alScreen.Width,
SystemInformati on.VirtualScree n.Height);

try

{

Graphics g=Graphics.From Image(bm);

System.IntPtr bmDC=g.GetHdc() ;

BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,desktopDC, 0,0,0x00CC0020 /*SRCCOPY*/);

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

ReleaseDC(Syste m.IntPtr.Zero, desktopDC);

g.ReleaseHdc(bm DC);

g.Dispose();

}

catch(Exception er)

{

MessageBox.Show (er.ToString()) ;

}

}

[Mark R. Dawson]

Hi Pohihihi,
on the line:

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

I believe that having a single \ will cause problems because \<char> is
regarded as an escape character.

Try:
bm.Save(@"C:\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
which the @ means use the literal value of the string ignoring escape
characters

or
bm.Save("C:\\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
Hope that helps.
Mark

"Pohihihi" wrote:

I am getting a generic GDI+ error on following code. Basically it is trying
to capture screen image and save in a file.
Is there a way to find more details on this error? Thanks for the help.

---------------------------
ERROR MSG
---------------------------
System.Runtime. InteropServices .ExternalExcept ion: A generic error occurred
in GDI+.
at System.Drawing. Image.Save(Stri ng filename, ImageCodecInfo encoder,
EncoderParamete rs encoderParams)
at System.Drawing. Image.Save(Stri ng filename, ImageFormat format)
at ScreenCapture.F orm1.TakeSnapNo w() in c:\visual studio
projects\screen capture\form1.c s:line 102

Sorry for the formating below.

//First, you need to import the BitBlt, GetDC and ReleaseDC functions.

//imports the GDI BitBlt function that enables the background of the window

//to be captured

[DllImport("gdi3 2.dll")]

private static extern bool BitBlt(

IntPtr hdcDest, // handle to destination DC

int nXDest, // x-coord of destination upper-left corner

int nYDest, // y-coord of destination upper-left corner

int nWidth, // width of destination rectangle

int nHeight, // height of destination rectangle

IntPtr hdcSrc, // handle to source DC

int nXSrc, // x-coordinate of source upper-left corner

int nYSrc, // y-coordinate of source upper-left corner

System.Int32 dwRop // raster operation code

);
[DllImport("User 32.dll")]

public extern static System.IntPtr GetDC(System.In tPtr hWnd);

[DllImport("User 32.dll")]

public extern static int ReleaseDC(Syste m.IntPtr hWnd, System.IntPtr hDC);
//modified to include hWnd
//Now, to capture the screen in it's entirety you can do the following.

public void TakeSnapNow()

{

System.IntPtr desktopDC=GetDC (System.IntPtr. Zero);

Bitmap bm=new Bitmap(SystemIn formation.Virtu alScreen.Width,
SystemInformati on.VirtualScree n.Height);

try

{

Graphics g=Graphics.From Image(bm);

System.IntPtr bmDC=g.GetHdc() ;

BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,desktopDC, 0,0,0x00CC0020 /*SRCCOPY*/);

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

ReleaseDC(Syste m.IntPtr.Zero, desktopDC);

g.ReleaseHdc(bm DC);

g.Dispose();

}

catch(Exception er)

{

MessageBox.Show (er.ToString()) ;

}

}

[Pohihihi]

Thanks Mark that was the real cause. I was looking all around to find the
problem.
I am still interested in learning how to trap errors while using interops.
"Mark R. Dawson" <Ma*********@di scussions.micro soft.com> wrote in message
news:51******** *************** ***********@mic rosoft.com...

Hi Pohihihi,
on the line:

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

I believe that having a single \ will cause problems because \<char> is
regarded as an escape character.

Try:
bm.Save(@"C:\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
which the @ means use the literal value of the string ignoring escape
characters

or
bm.Save("C:\\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
Hope that helps.
Mark

"Pohihihi" wrote:

I am getting a generic GDI+ error on following code. Basically it is
trying
to capture screen image and save in a file.
Is there a way to find more details on this error? Thanks for the help.

---------------------------
ERROR MSG
---------------------------
System.Runtime. InteropServices .ExternalExcept ion: A generic error
occurred
in GDI+.
at System.Drawing. Image.Save(Stri ng filename, ImageCodecInfo encoder,
EncoderParamete rs encoderParams)
at System.Drawing. Image.Save(Stri ng filename, ImageFormat format)
at ScreenCapture.F orm1.TakeSnapNo w() in c:\visual studio
projects\screen capture\form1.c s:line 102

Sorry for the formating below.

//First, you need to import the BitBlt, GetDC and ReleaseDC functions.

//imports the GDI BitBlt function that enables the background of the
window

//to be captured

[DllImport("gdi3 2.dll")]

private static extern bool BitBlt(

IntPtr hdcDest, // handle to destination DC

int nXDest, // x-coord of destination upper-left corner

int nYDest, // y-coord of destination upper-left corner

int nWidth, // width of destination rectangle

int nHeight, // height of destination rectangle

IntPtr hdcSrc, // handle to source DC

int nXSrc, // x-coordinate of source upper-left corner

int nYSrc, // y-coordinate of source upper-left corner

System.Int32 dwRop // raster operation code

);
[DllImport("User 32.dll")]

public extern static System.IntPtr GetDC(System.In tPtr hWnd);

[DllImport("User 32.dll")]

public extern static int ReleaseDC(Syste m.IntPtr hWnd, System.IntPtr
hDC);
//modified to include hWnd
//Now, to capture the screen in it's entirety you can do the following.

public void TakeSnapNow()

{

System.IntPtr desktopDC=GetDC (System.IntPtr. Zero);

Bitmap bm=new Bitmap(SystemIn formation.Virtu alScreen.Width,
SystemInformati on.VirtualScree n.Height);

try

{

Graphics g=Graphics.From Image(bm);

System.IntPtr bmDC=g.GetHdc() ;

BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,desktopDC, 0,0,0x00CC0020 /*SRCCOPY*/);

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

ReleaseDC(Syste m.IntPtr.Zero, desktopDC);

g.ReleaseHdc(bm DC);

g.Dispose();

}

catch(Exception er)

{

MessageBox.Show (er.ToString()) ;

}

}

[Mark R. Dawson]

For looking what the exact error was through the interop services you can get
the last error from the Win32 calls, although you cannot call the
GetLastError method directly, you must go through a method called
GetLastWin32Err or.

Basically make sure you have imported the namespace
System.Runtime. InteropServices then when you import a DLL you need to set the
SetLastError property to true i.e.

[DllImport("gdi3 2.dll", SetLastError=tr ue)]

Then when you have an exception you can do:

intError = Marshal.GetLast Win32Error();

which returns the error code.

I am not an expert in this, but this might be enough to get you pointed in
the right direction.

Hope that helps
Mark.

"Pohihihi" wrote:

Thanks Mark that was the real cause. I was looking all around to find the
problem.
I am still interested in learning how to trap errors while using interops.
"Mark R. Dawson" <Ma*********@di scussions.micro soft.com> wrote in message
news:51******** *************** ***********@mic rosoft.com...

Hi Pohihihi,
on the line:

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

I believe that having a single \ will cause problems because \<char> is
regarded as an escape character.

Try:
bm.Save(@"C:\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
which the @ means use the literal value of the string ignoring escape
characters

or
bm.Save("C:\\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
Hope that helps.
Mark

"Pohihihi" wrote:

I am getting a generic GDI+ error on following code. Basically it is
trying
to capture screen image and save in a file.
Is there a way to find more details on this error? Thanks for the help.

---------------------------
ERROR MSG
---------------------------
System.Runtime. InteropServices .ExternalExcept ion: A generic error
occurred
in GDI+.
at System.Drawing. Image.Save(Stri ng filename, ImageCodecInfo encoder,
EncoderParamete rs encoderParams)
at System.Drawing. Image.Save(Stri ng filename, ImageFormat format)
at ScreenCapture.F orm1.TakeSnapNo w() in c:\visual studio
projects\screen capture\form1.c s:line 102

Sorry for the formating below.

//First, you need to import the BitBlt, GetDC and ReleaseDC functions.

//imports the GDI BitBlt function that enables the background of the
window

//to be captured

[DllImport("gdi3 2.dll")]

private static extern bool BitBlt(

IntPtr hdcDest, // handle to destination DC

int nXDest, // x-coord of destination upper-left corner

int nYDest, // y-coord of destination upper-left corner

int nWidth, // width of destination rectangle

int nHeight, // height of destination rectangle

IntPtr hdcSrc, // handle to source DC

int nXSrc, // x-coordinate of source upper-left corner

int nYSrc, // y-coordinate of source upper-left corner

System.Int32 dwRop // raster operation code

);
[DllImport("User 32.dll")]

public extern static System.IntPtr GetDC(System.In tPtr hWnd);

[DllImport("User 32.dll")]

public extern static int ReleaseDC(Syste m.IntPtr hWnd, System.IntPtr
hDC);
//modified to include hWnd
//Now, to capture the screen in it's entirety you can do the following.

public void TakeSnapNow()

{

System.IntPtr desktopDC=GetDC (System.IntPtr. Zero);

Bitmap bm=new Bitmap(SystemIn formation.Virtu alScreen.Width,
SystemInformati on.VirtualScree n.Height);

try

{

Graphics g=Graphics.From Image(bm);

System.IntPtr bmDC=g.GetHdc() ;

BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,desktopDC, 0,0,0x00CC0020 /*SRCCOPY*/);

bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );

ReleaseDC(Syste m.IntPtr.Zero, desktopDC);

g.ReleaseHdc(bm DC);

g.Dispose();

}

catch(Exception er)

{

MessageBox.Show (er.ToString()) ;

}

}

[Pohihihi]

Thanks Mark, it is a nice start for me, I will dig more in interops on MSDN.
"Mark R. Dawson" <Ma*********@di scussions.micro soft.com> wrote in message
news:EF******** *************** ***********@mic rosoft.com...

For looking what the exact error was through the interop services you can
get
the last error from the Win32 calls, although you cannot call the
GetLastError method directly, you must go through a method called
GetLastWin32Err or.

Basically make sure you have imported the namespace
System.Runtime. InteropServices then when you import a DLL you need to set
the
SetLastError property to true i.e.

[DllImport("gdi3 2.dll", SetLastError=tr ue)]

Then when you have an exception you can do:

intError = Marshal.GetLast Win32Error();

which returns the error code.

I am not an expert in this, but this might be enough to get you pointed in
the right direction.

Hope that helps
Mark.

"Pohihihi" wrote:

Thanks Mark that was the real cause. I was looking all around to find the
problem.
I am still interested in learning how to trap errors while using
interops.
"Mark R. Dawson" <Ma*********@di scussions.micro soft.com> wrote in message
news:51******** *************** ***********@mic rosoft.com...

> Hi Pohihihi,
> on the line:
>
> bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );
>
> I believe that having a single \ will cause problems because \<char> is
> regarded as an escape character.
>
> Try:
> bm.Save(@"C:\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
> which the @ means use the literal value of the string ignoring escape
> characters
>
> or
> bm.Save("C:\\fi le.bmp",System. Drawing.Imaging .ImageFormat.Bm p);
>
>
> Hope that helps.
> Mark
>
> "Pohihihi" wrote:
>
>> I am getting a generic GDI+ error on following code. Basically it is
>> trying
>> to capture screen image and save in a file.
>> Is there a way to find more details on this error? Thanks for the
>> help.
>>
>> ---------------------------
>> ERROR MSG
>> ---------------------------
>> System.Runtime. InteropServices .ExternalExcept ion: A generic error
>> occurred
>> in GDI+.
>> at System.Drawing. Image.Save(Stri ng filename, ImageCodecInfo
>> encoder,
>> EncoderParamete rs encoderParams)
>> at System.Drawing. Image.Save(Stri ng filename, ImageFormat format)
>> at ScreenCapture.F orm1.TakeSnapNo w() in c:\visual studio
>> projects\screen capture\form1.c s:line 102
>>
>>
>>
>> Sorry for the formating below.
>>
>> //First, you need to import the BitBlt, GetDC and ReleaseDC functions.
>>
>> //imports the GDI BitBlt function that enables the background of the
>> window
>>
>> //to be captured
>>
>> [DllImport("gdi3 2.dll")]
>>
>> private static extern bool BitBlt(
>>
>> IntPtr hdcDest, // handle to destination DC
>>
>> int nXDest, // x-coord of destination upper-left corner
>>
>> int nYDest, // y-coord of destination upper-left corner
>>
>> int nWidth, // width of destination rectangle
>>
>> int nHeight, // height of destination rectangle
>>
>> IntPtr hdcSrc, // handle to source DC
>>
>> int nXSrc, // x-coordinate of source upper-left corner
>>
>> int nYSrc, // y-coordinate of source upper-left corner
>>
>> System.Int32 dwRop // raster operation code
>>
>> );
>>
>>
>> [DllImport("User 32.dll")]
>>
>> public extern static System.IntPtr GetDC(System.In tPtr hWnd);
>>
>> [DllImport("User 32.dll")]
>>
>> public extern static int ReleaseDC(Syste m.IntPtr hWnd, System.IntPtr
>> hDC);
>> //modified to include hWnd
>>
>>
>> //Now, to capture the screen in it's entirety you can do the
>> following.
>>
>> public void TakeSnapNow()
>>
>> {
>>
>> System.IntPtr desktopDC=GetDC (System.IntPtr. Zero);
>>
>> Bitmap bm=new Bitmap(SystemIn formation.Virtu alScreen.Width,
>> SystemInformati on.VirtualScree n.Height);
>>
>> try
>>
>> {
>>
>> Graphics g=Graphics.From Image(bm);
>>
>> System.IntPtr bmDC=g.GetHdc() ;
>>
>> BitBlt(bmDC,0,0 ,bm.Width,bm.He ight,desktopDC, 0,0,0x00CC0020
>> /*SRCCOPY*/);
>>
>> bm.Save("C:\fil e.bmp",System.D rawing.Imaging. ImageFormat.Bmp );
>>
>> ReleaseDC(Syste m.IntPtr.Zero, desktopDC);
>>
>> g.ReleaseHdc(bm DC);
>>
>> g.Dispose();
>>
>> }
>>
>> catch(Exception er)
>>
>> {
>>
>> MessageBox.Show (er.ToString()) ;
>>
>> }
>>
>> }
>>
>>
>>
>>