RosettaCodeData/Task/Window-creation/Delphi/window-creation-2.pas

64 lines
2.3 KiB
ObjectPascal

program Project3;
uses
Windows,
Messages;
var
WndClass: TWndClass;
Msg: TMsg;
winT, winL: Integer;
// Initial height/width of the window
const
winW: Integer = 800;
winH: Integer = 600;
// Callback function to processes messages sent to the window
function WindowProc(hWnd,Msg,wParam,lParam:Integer): Integer; stdcall;
begin
// Trap the WM_DESTROY message
if (Msg = WM_DESTROY) then PostQuitMessage(0);
Result := DefWindowProc(hWnd,Msg,wParam,lParam);
end;
begin
// Fill the WndClass structure with the window class attributes
// to be registered by the RegisterClass function
with WndClass do
begin
lpszClassName:= 'Form1';
lpfnWndProc := @WindowProc; // Pointer to our message handling callback
style := CS_OWNDC or // Request a unique device context
CS_VREDRAW or // Redraw window when resized vertically
CS_HREDRAW; // Redraw window when resized horizontally
hInstance := hInstance; // The instance that the window procedure of this class is within
hbrBackground := HBRUSH(COLOR_BTNFACE+1); // Background colour of the window
end;
// Register the window class for use by CreateWindow
RegisterClass(WndClass);
// Calculate initial top and left positions of the window
winT := (GetSystemMetrics(SM_CYFULLSCREEN) - winH) div 2;
winL := (GetSystemMetrics(SM_CXFULLSCREEN) - winW) div 2;
// Create the window
CreateWindow(WndClass.lpszClassName, // Class name
'Form1', // Window name
WS_OVERLAPPEDWINDOW or WS_VISIBLE, // Window style
winL, // Horizontal Position (Left)
winT, // Vertical Position (Top)
winW, // Width
winH, // Height
0, // Window parent/owner handle
0, // Menu handle
hInstance, // Handle to application instance
nil); // Pointer to window creation data
// Handle messages
while GetMessage(Msg,0,0,0) do
DispatchMessage(Msg);
end.