If you want simulate the printscreen in C++.
Try this small example then...
#include <windows.h>
char EditText[256];
int EditTextLength;
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
char szClassName[ ] = "WindowsApp";
int WINAPI WinMain (HINSTANCE hThisInstance,
HINSTANCE hPrevInstance,
LPSTR lpszArgument,
int nCmdShow)
{
HWND hwnd;
MSG messages;
WNDCLASSEX wincl;
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure;
wincl.style = CS_DBLCLKS;
wincl.cbSize = sizeof (WNDCLASSEX);
wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
wincl.lpszMenuName = NULL;
wincl.cbClsExtra = 0;
wincl.cbWndExtra = 0;
wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
if (!RegisterClassEx (&wincl))
return 0;
hwnd = CreateWindowEx (
0,
szClassName,
"Clipboard Windows App",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
544,
375,
HWND_DESKTOP,
NULL,
hThisInstance,
NULL
);
ShowWindow (hwnd, nCmdShow);
while (GetMessage (&messages, NULL, 0, 0))
{
TranslateMessage(&messages);
DispatchMessage(&messages);
}
return messages.wParam;
}
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static HWND hwndButton;
static HWND hwndEdit;
HGLOBAL hGlobal;
PSTR pGlobal;
switch (message)
{
case WM_CREATE:
hwndButton = CreateWindow ( TEXT ("button"),"Cut Text",WS_CHILD|WS_VISIBLE|1,55,100,100,25,hwnd,(HMENU) 1,((LPCREATESTRUCT) lParam) -> hInstance,NULL);
hwndEdit = CreateWindow (TEXT ("edit"),NULL,WS_CHILD| ES_LEFT|WS_BORDER| WS_VISIBLE,55, 50, 100, 25, hwnd,
(HMENU) 1,((LPCREATESTRUCT) lParam) -> hInstance ,NULL);
return 0;
case WM_COMMAND:
switch (wParam)
{
case 1:
EditTextLength = GetWindowTextLength(hwndEdit) +1;
GetWindowText(hwndEdit, EditText, EditTextLength);
hGlobal = GlobalAlloc(GHND|GMEM_SHARE,
EditTextLength*sizeof (char));
pGlobal = (char*)GlobalLock (hGlobal);
strcpy (pGlobal, EditText);
GlobalUnlock(hGlobal);
OpenClipboard(hwnd);
EmptyClipboard();
SetClipboardData(CF_TEXT, hGlobal);
CloseClipboard();
break;
}
return 0;
case WM_DESTROY:
PostQuitMessage (0);
break;
default:
return DefWindowProc (hwnd, message, wParam, lParam);
}
return 0;
}
</windows.h>