#include <windows.h>
#include <stdio.h>


PBITMAPINFO CreateBitmapInfoStruct(HBITMAP hBmp){
    BITMAP bmp;
    PBITMAPINFO pbmi;
    WORD    cClrBits;

    // Retrieve the bitmap color format, width, and height.
    GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp);

    // Convert the color format to a count of bits.
    cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
    if (cClrBits == 1)
        cClrBits = 1;
    else if (cClrBits <= 4)
        cClrBits = 4;
    else if (cClrBits <= 8)
        cClrBits = 8;
    else if (cClrBits <= 16)
        cClrBits = 16;
    else if (cClrBits <= 24)
        cClrBits = 24;
    else cClrBits = 32;

    // Allocate memory for the BITMAPINFO structure. (This structure
    // contains a BITMAPINFOHEADER structure and an array of RGBQUAD
    // data structures.)

     if (cClrBits != 24) pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * (1<< cClrBits));

     // There is no RGBQUAD array for the 24-bit-per-pixel format.

     else pbmi = (PBITMAPINFO) LocalAlloc(LPTR, sizeof(BITMAPINFOHEADER));

    // Initialize the fields in the BITMAPINFO structure.

    pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    pbmi->bmiHeader.biWidth = bmp.bmWidth;
    pbmi->bmiHeader.biHeight = bmp.bmHeight;
    pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
    pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
    if (cClrBits < 24) pbmi->bmiHeader.biClrUsed = (1<<cClrBits);

    // If the bitmap is not compressed, set the BI_RGB flag.
    pbmi->bmiHeader.biCompression = BI_RGB;

    // Compute the number of bytes in the array of color
    // indices and store the result in biSizeImage.
    // For Windows NT, the width must be DWORD aligned unless
    // the bitmap is RLE compressed. This example shows this.
    // For Windows 95/98/Me, the width must be WORD aligned unless the
    // bitmap is RLE compressed.
    pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8 * pbmi->bmiHeader.biHeight;
    // Set biClrImportant to 0, indicating that all of the
    // device colors are important.
     pbmi->bmiHeader.biClrImportant = 0;
     return pbmi;
 }

void CreateBMPFile(LPTSTR pszFile, PBITMAPINFO pbi, HBITMAP hBMP, HDC hDC){
     HANDLE hf;                 // file handle
    BITMAPFILEHEADER hdr;       // bitmap file-header
    PBITMAPINFOHEADER pbih;     // bitmap info-header
    LPBYTE lpBits;              // memory pointer
    WORD dwTotal;              // total count of bytes
    WORD cb;                   // incremental count of bytes
    BYTE *hp;                   // byte pointer
    WORD dwTmp;

    pbih = (PBITMAPINFOHEADER) pbi;
    lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);

    // Retrieve the color table (RGBQUAD array) and the bits
    // (array of palette indices) from the DIB.
    GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, DIB_RGB_COLORS);

// Create the .BMP file.
    hf = CreateFile(pszFile, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    hdr.bfType = 0x4d42;        // 0x42 = "B" 0x4d = "M"
    // Compute the size of the entire file.
    hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed * sizeof(RGBQUAD) + pbih->biSizeImage);
    hdr.bfReserved1 = 0;
    hdr.bfReserved2 = 0;

    // Compute the offset to the array of color indices.
    hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + pbih->biSize + pbih->biClrUsed * sizeof (RGBQUAD);

    // Copy the BITMAPFILEHEADER into the .BMP file.
    WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp,  NULL);

    // Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
    WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) + pbih->biClrUsed * sizeof (RGBQUAD), (LPDWORD) &dwTmp, NULL);

    // Copy the array of color indices into the .BMP file.
    dwTotal = cb = pbih->biSizeImage;
    hp = lpBits;
    WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL);

    // Close the .BMP file.
    CloseHandle(hf);

    // Free memory.
    GlobalFree((HGLOBAL)lpBits);
}


void main(int argc, char *argv[]{
int sx = GetSystemMetrics(SM_CXSCREEN), sy = GetSystemMetrics(SM_CYSCREEN);
HDC hDC = GetDC(GetDesktopWindow());
HDC MyHDC = CreateCompatibleDC(hDC);
HBITMAP hBMP = CreateCompatibleBitmap(hDC, sx, sy);
SelectObject(MyHDC, hBMP);
LOGBRUSH MyBrush;
MyBrush.lbStyle = BS_SOLID;
MyBrush.lbColor = 0xFF0000;
HBRUSH hBrush = CreateBrushIndirect(&MyBrush);
RECT MyRect = {0, 0, sx, sy};
FillRect(MyHDC, &MyRect, hBrush);

BitBlt(MyHDC, 0, 0, sx, sy, hDC, 0, 0, SRCCOPY);
if(argc==2) CreateBMPFile(argv[1], CreateBitmapInfoStruct(hBMP), hBMP, MyHDC);

for(int i=0; i<argc; i++) printf("Argument #%d: %s\n", i, argv[i];
printf("esktop DC = %d\nHBITMAP hBMP = %d", (int)hDC, (int)hBMP);
}

Option Explicit

Private Declare Function OleCreatePictureIndirect Lib "oleaut32" (ByRef lpPictDesc As PicBmp, riid As GUID, ByVal fOwn As Long, ByRef lplpvObj As Any) As Long
Private Declare Function BitBlt Lib "gdi32.dll" (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Long, ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, ByVal dwRop As Long) As Long
Private Declare Function CreateCompatibleBitmap Lib "gdi32.dll" (ByVal hdc As Long, ByVal nWidth As Long, ByVal nHeight As Long) As Long
Private Declare Function CreateCompatibleDC Lib "gdi32.dll" (ByVal hdc As Long) As Long
Private Declare Function DeleteObject Lib "gdi32.dll" (ByVal hObject As Long) As Long
Private Declare Function GetDC Lib "user32.dll" (ByVal hwnd As Long) As Long
Private Declare Function ReleaseDC Lib "user32.dll" (ByVal hwnd As Long, ByVal hdc As Long) As Long
Private Declare Function SelectObject Lib "gdi32.dll" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function DeleteDC Lib "gdi32.dll" (ByVal hdc As Long) As Long

Private Type GUID
  ata1 As Long
  ata2 As Integer
  ata3 As Integer
  ata4(0 To 7) As Byte
End Type

Private Type PicBmp
  Size As Long
  Type As PictureTypeConstants
  hBmp As Long
  hPal As Long
  Reserved As Long
End Type

Private Function GetPicture(ByVal hBmp As Long) As IPictureDisp
  Dim p As PicBmp, g As GUID
  
  With p
    .hBmp = hBmp
    .Size = Len(p)
    .Type = vbPicTypeBitmap
  End With
  
  'IDispatch
  With g
    .Data1 = &H20400
    .Data4(0) = &HC0
    .Data4(7) = &H46
  End With
  
  OleCreatePictureIndirect p, g, 1, GetPicture
End Function

Private Function GetScreen(ByVal x As Long, ByVal y As Long, ByVal width As Long, ByVal height As Long) As IPictureDisp
  Dim h As Long, hd As Long, hb As Long
  
  h = GetDC(0)
  
  hd = CreateCompatibleDC(h)
  hb = CreateCompatibleBitmap(h, width, height)
  eleteObject SelectObject(hd, hb)
  
  BitBlt hd, 0, 0, width, height, h, x, y, vbSrcCopy
  Set GetScreen = GetPicture(hb)
  
  eleteObject hb
  eleteDC hd
  ReleaseDC 0, h
End Function


Private Sub Form_Load()
  Dim p As IPictureDisp
  
  Set p = GetScreen(500, 400, 200, 200)
  
  Picture1.Picture = p
  Picture2.Picture = p
  Picture3.Picture = p
End Sub

Можно получить содержимое рисунка в байтовый массив с помощью GetBimapBits.

Private Type PicBmp
  Size As Long
  [B]Type[/B] As PictureTypeConstants
  hBmp As Long
  hPal As Long
  Reserved As Long
End Type

Winsock1.Connect <IP>, <Port>
WinSock1.SendData <имя переменной>

Private Type PicBmp
  Size As Long
  [B]Type[/B] As PictureTypeConstants
  hBmp As Long
  hPal As Long
  Reserved As Long
End Type

Конечно, не получается, нельзя использовать имя переменной как лючевое слово("Type"

object.SendData data

data
Data to be sent. For binary data, byte array should be used.

Dim btData () As Byte
ReDim btData (249)