Data update

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

@@ -0,0 +1,63 @@
+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.