[Kuk]

Hrmcobol, aquí va el código y la DLL compilada:

#include <Windows.h>
#include <Gdiplus.h>
 
#define DllExport __declspec( dllexport )
 
extern "C" {
 
DllExport void __stdcall ScreenShot(char*BmpName, HWND WndHwnd)
{
    RECT DesktopParams;
    HDC DevC = GetDC(WndHwnd);
    GetWindowRect(WndHwnd,&DesktopParams);
    DWORD Width = DesktopParams.right - DesktopParams.left;
    DWORD Height = DesktopParams.bottom - DesktopParams.top;
 
    DWORD FileSize = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+(sizeof(RGBTRIPLE)+1*(Width*Height*4));
    char *BmpFileData = (char*)GlobalAlloc(0x0040,FileSize);
 
    PBITMAPFILEHEADER BFileHeader = (PBITMAPFILEHEADER)BmpFileData;
    PBITMAPINFOHEADER  BInfoHeader = (PBITMAPINFOHEADER)&BmpFileData[sizeof(BITMAPFILEHEADER)];
 
    BFileHeader->bfType = 0x4D42; // BM
    BFileHeader->bfSize = sizeof(BITMAPFILEHEADER);
    BFileHeader->bfOffBits = sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
 
    BInfoHeader->biSize = sizeof(BITMAPINFOHEADER);
    BInfoHeader->biPlanes = 1;
    BInfoHeader->biBitCount = 24;
    BInfoHeader->biCompression = BI_RGB;
    BInfoHeader->biHeight = Height;
    BInfoHeader->biWidth = Width;
 
    RGBTRIPLE *Image = (RGBTRIPLE*)&BmpFileData[sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)];
    RGBTRIPLE color;
 
    HDC CaptureDC = CreateCompatibleDC(DevC);
    HBITMAP CaptureBitmap = CreateCompatibleBitmap(DevC,Width,Height);
    SelectObject(CaptureDC,CaptureBitmap);
    BitBlt(CaptureDC,0,0,Width,Height,DevC,0,0,SRCCOPY|CAPTUREBLT);
    GetDIBits(CaptureDC,CaptureBitmap,0,Height,Image,(LPBITMAPINFO)BInfoHeader, DIB_RGB_COLORS);
 
    DWORD Junk;
    HANDLE FH = CreateFileA(BmpName,GENERIC_WRITE,FILE_SHARE_WRITE,0,CREATE_ALWAYS,0,0);
    WriteFile(FH,BmpFileData,FileSize,&Junk,0);
    CloseHandle(FH);
        GlobalFree(BmpFileData);
}
 
} //undecorate

Para llamar la función desde PowerCOBOL, en el fichero COBOL85.CBR ponemos:

[MainForm.Entry]
ScreenShot=PrintScreen.dll

En el código:

 ENVIRONMENT     DIVISION.
 DATA            DIVISION.
 WORKING-STORAGE SECTION.
 01  PrinScreen  PIC X(50)  VALUE "ScreenShot". 
 01  WsPath      PIC X(250).
 01  FrmHWND     PIC S9(9) COMP-5.
 PROCEDURE       DIVISION.
     
     MOVE "hwnd" OF POW-SELF TO FrmHWND
     MOVE "C:\001.BMP"       TO WsPath
     
     CALL PrinScreen WITH STDCALL USING BY REFERENCE WsPath
                                        BY VALUE FrmHWND