StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POCorrect way to repeatedly blit to window DC?
text
Body
copied!<p>I have put a procedure for capturing screenshots into memoryDC in a Winapi timer. I can successfully blit the said image to the window, but how would i do this repeatedly, lets say every 1-2 seconds?</p> <p>The currenct code i have can blit it 1-2 seconds at a time, but it wont blit it to the Window correctly (the image is misplaced).</p> <p>How shall i go about doing this?</p> <pre><code> #include <windows.h> #include <iostream> #include <windowsx.h> #define TIMERID 3232 /* Declare Windows procedure */ LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM); RECT rectangle{ 50, 50, 690, 409 }; /* Make the class name into a global variable */ char szClassName[ ] = "CodeBlocksWindowsApp"; HDC handle_WindowDC; HDC handle_MemoryDC; HDC handle_ScreenDC; //BITMAP bitmap; HBITMAP handle_Bitmap; int x, y; HWND hand; int WINAPI WinMain (HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nCmdShow) { HWND hwnd; /* This is the handle for our window */ MSG messages; /* Here messages to the application are saved */ WNDCLASSEX wincl; /* Data structure for the windowclass */ /* The Window structure */ wincl.hInstance = hThisInstance; wincl.lpszClassName = szClassName; wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */ wincl.style = CS_DBLCLKS; /* Catch double-clicks */ wincl.cbSize = sizeof (WNDCLASSEX); /* Use default icon and mouse-pointer */ wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION); wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION); wincl.hCursor = LoadCursor (NULL, IDC_ARROW); wincl.lpszMenuName = NULL; /* No menu */ wincl.cbClsExtra = 0; /* No extra bytes after the window class */ wincl.cbWndExtra = 0; /* structure or the window instance */ /* Use Windows's default colour as the background of the window */ wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND; /* Register the window class, and if it fails quit the program */ if (!RegisterClassEx (&wincl)) return 0; /* The class is registered, let's create the program*/ hwnd = CreateWindowEx ( 0, /* Extended possibilites for variation */ szClassName, /* Classname */ "Code::Blocks Template Windows App", /* Title Text */ WS_OVERLAPPEDWINDOW, /* default window */ CW_USEDEFAULT, /* Windows decides the position */ CW_USEDEFAULT, /* where the window ends up on the screen */ 1600, /* The programs width */ 900, /* and height in pixels */ HWND_DESKTOP, /* The window is a child-window to desktop */ NULL, /* No menu */ hThisInstance, /* Program Instance handler */ NULL /* No Window Creation data */ ); /* Make the window visible on the screen */ ShowWindow (hwnd, nCmdShow); SetTimer(hwnd, TIMERID, 1000, (TIMERPROC)NULL); /* Run the message loop. It will run until GetMessage() returns 0 */ while (GetMessage (&messages, NULL, 0, 0)) { /* Translate virtual-key messages into character messages */ TranslateMessage(&messages); /* Send message to WindowProcedure */ DispatchMessage(&messages); } /* The program return-value is 0 - The value that PostQuitMessage() gave */ return messages.wParam; } /* This function is called by the Windows function DispatchMessage() */ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { switch (message) /* handle the messages */ { case WM_CREATE:{ } //hand = CreateWindowEx(NULL, "STATIC", "", SS_BITMAP|WS_VISIBLE, 500,300, 640 ,360 , hwnd, HMENU(IDCSTATIC_BITMAP), GetModuleHandle(NULL), NULL); } break; case WM_TIMER: switch(LOWORD(wParam)){ case TIMERID:{ //MessageBox(NULL,NULL,NULL,NULL); handle_ScreenDC = GetDC(NULL); handle_MemoryDC = CreateCompatibleDC(handle_ScreenDC); x = GetDeviceCaps(handle_ScreenDC, HORZRES); y = GetDeviceCaps(handle_ScreenDC, VERTRES); handle_Bitmap = CreateCompatibleBitmap(handle_ScreenDC, 640, 360); SelectObject(handle_MemoryDC, handle_Bitmap); StretchBlt(handle_MemoryDC, 0, 0, 640, 360, handle_ScreenDC, 0, 0, x, y, SRCCOPY); UpdateWindow(hwnd); BitBlt(handle_WindowDC, 50, 50, x, y, handle_MemoryDC, 0, 0, SRCCOPY); } break; }break; case WM_PAINT:{ PAINTSTRUCT paintstruct; handle_WindowDC = BeginPaint(hwnd, &paintstruct); //BitBlt(handle_WindowDC, 50, 50, x, y, handle_MemoryDC, 0, 0, SRCCOPY); EndPaint(hwnd, &paintstruct); } break; case WM_DESTROY: PostQuitMessage (0); /* send a WM_QUIT to the message queue */ break; case WM_LBUTTONDOWN:{ std::cout <<"\nx: " << GET_X_LPARAM(lParam) << "\ny: " << GET_Y_LPARAM(lParam); tagPOINT point; point.x = GET_X_LPARAM(lParam); point.y = GET_Y_LPARAM(lParam); if( PtInRect(&rectangle, point)){ int x, y; x = 2.5*(point.x - 50); y = 2.5*(point.y - 50); //I juse use setcursorpos for now, but when connecting to server.exe i will do a send() and send x,y coordinates along with //a click or rightclick, or whatever. SetCursorPos(x, y); } } break; default: /* for messages that we don't deal with */ return DefWindowProc (hwnd, message, wParam, lParam); } return 0; } </code></pre>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload