How to create a window without a border and with a shadow, like a github application?

Question

how to create a window that has no border, but it behaves like a border. e.g. git -hub app window, it has a shadow effect. How to create a window like this.
Thanks. using win 32 C ++.

I tried to handle the wm_Ncpaint call but didn't use it.

#include "stdafx.h" #include "CustomWindow.h" LONG_PTR g_lpCustomWindowptr = NULL; BOOL g_bStateofWindow = TRUE; // creating window CreateWindowEx(WS_EX_ACCEPTFILES, szWindowClass, szTitle, WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL); void CustomWindow::CreateCustomWindow(HWND hwnd) { // To set border and handling Doc with default cases LONG_PTR lpStyle = GetWindowLongPtr(hwnd, GWL_STYLE); lpStyle &= ~(WS_CAPTION | WS_ACTIVECAPTION ); //lpStyle |= WS_THICKFRAME; SetWindowLongPtr(hwnd, GWL_STYLE, lpStyle); //set the customized proc. g_lpCustomWindowptr = SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)CustonWindow_WndProc); } LRESULT CALLBACK CustomWindow::CustonWindow_WndProc(IN HWND hwnd, IN UINT message, IN WPARAM wParam, IN LPARAM lParam) { switch (message) { case WM_SIZE: { if (SIZE_MAXIMIZED == wParam) { HMONITOR hmon= MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST); MONITORINFO moninfo = {0}; moninfo.cbSize= sizeof(moninfo); GetMonitorInfo(hmon, &moninfo); SetWindowPos(hwnd, HWND_TOP, moninfo.rcWork.left, moninfo.rcWork.top, moninfo.rcWork.right, moninfo.rcWork.bottom, SWP_FRAMECHANGED | SWP_NOREDRAW); } } break; case WM_NCACTIVATE : { if (TRUE == wParam) { SendMessage(hwnd,WM_NCPAINT,wParam,0); } else if(FALSE == wParam ) { SendMessage(hwnd,WM_NCPAINT,wParam,0); } return true; } case WM_NCCALCSIZE: { return 0; } break; case WM_NCPAINT: { HDC hDC; hDC = GetWindowDC(hwnd); HPEN hPen = CreatePen(PS_SOLID, 5, RGB(0,0,255));; SelectObject(hDC, hPen); RECT rcClientRect = {0}; GetClientRect(hwnd,&rcClientRect); if(FALSE == wParam) { MoveToEx(hDC,rcClientRect.left,rcClientRect.top,NULL); LineTo(hDC,rcClientRect.right - 1,rcClientRect.top ); LineTo(hDC,rcClientRect.right - 1,rcClientRect.bottom - 1 ); LineTo(hDC,rcClientRect.left,rcClientRect.bottom - 1); LineTo(hDC,rcClientRect.left,rcClientRect.top); } else { HPEN hPen1 = CreatePen(PS_SOLID, 5, RGB(255,0,0));; SelectObject(hDC, hPen1); MoveToEx(hDC,rcClientRect.left,rcClientRect.top,NULL); LineTo(hDC,rcClientRect.right - 1,rcClientRect.top ); LineTo(hDC,rcClientRect.right - 1,rcClientRect.bottom - 1 ); LineTo(hDC,rcClientRect.left,rcClientRect.bottom - 1); LineTo(hDC,rcClientRect.left,rcClientRect.top); } ReleaseDC(hwnd, hDC); } } break; } return CallWindowProc((WNDPROC)g_lpCustomWindowptr, hwnd, message, wParam, lParam); } 

Answer 1

To create a window without a frame, system menu and title, but with the shadow of Aero, you need to do the following:

• Create window with WS_CAPTION style
• A DwmExtendFrameIntoClientArea WDM API call passing with a 1 pixel top margin
• Handle the WM_NCCALCSIZE message, do not divert the DefWindowProc call while processing this message, but simply return 0

Here is a simple example that creates such a window using a pure Windows API written in Delphi:

 program BorderlessWindow; uses DwmApi, Winapi.UxTheme, Windows, SysUtils, Messages; {$R *.res} var Msg : TMSG; LWndClass : TWndClass; hMainHandle: HWND; lMargins: TMargins; procedure ReleaseResources; begin PostQuitMessage(0); end; function WindowProc(hWnd,Msg:Longint; wParam : WPARAM; lParam: LPARAM):Longint; stdcall; begin case Msg of WM_DESTROY: ReleaseResources; WM_NCHITTEST: Exit(HTCAPTION); // This is needed only to move window with mouse WM_NCCALCSIZE: Exit(0); // This line will hide default window border and caption end; Result:=DefWindowProc(hWnd,Msg,wParam,lParam); end; begin //create the window LWndClass.hInstance := hInstance; with LWndClass do begin lpszClassName := 'MyWinApiWnd'; Style := 0;//CS_PARENTDC or CS_BYTEALIGNCLIENT; hIcon := LoadIcon(hInstance,'MAINICON'); lpfnWndProc := @WindowProc; hbrBackground := COLOR_BTNFACE+1; hCursor := LoadCursor(0,IDC_ARROW); end; RegisterClass(LWndClass); hMainHandle := CreateWindow(LWndClass.lpszClassName,nil, WS_CAPTION or WS_VISIBLE, (GetSystemMetrics(SM_CXSCREEN) div 2)-190, (GetSystemMetrics(SM_CYSCREEN) div 2)-170, 386,200,0,0,hInstance,nil); if DwmCompositionEnabled then begin // This API call adds aero shadow lMargins.cyTopHeight := 1; DwmExtendFrameIntoClientArea(hMainHandle, lMargins); end; //message loop while GetMessage(Msg,0,0,0) do begin TranslateMessage(Msg); DispatchMessage(Msg); end; end.