初学win 32 窗体创建hwnd 遇到创建hwnd为空 请问什么原因
以下是 全部代码，建Win32 空项目，c.bmp文件一个#include <windows.h>
#include <iostream>
#include <time.h>
using namespace std;
const string APPTITLE = "Game Loop";
HWND window;
HDC device;
bool gameover = false;
void DrawBitmap(char *filename, int x, int y)
{
HBITMAP image = (HBITMAP)LoadImage(0, "c.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
BITMAP bm;
GetObject(image, sizeof(BITMAP), &bm);
HDC hdcImage = CreateCompatibleDC(device);
SelectObject(hdcImage, image);
BitBlt(device, x, y, bm.bmWidth, bm.bmHeight, hdcImage, 0, 0, SRCCOPY);
DeleteDC(hdcImage);
DeleteObject((HBITMAP)image);
}
bool Game_Init()
{
srand(time(NULL));
return 1;
}
void Game_Run()
{
if (gameover == true) return;
RECT rect;
GetClientRect(window, &rect);
int x = rand() % (rect.right - rect.left);
int y = rand() % (rect.bottom - rect.top);
DrawBitmap("c.bmp", x, y);
}
void Game_End()
{
ReleaseDC(window, device);
}
LRESULT CALLBACK WinProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_DESTROY:
gameover = true;
PostQuitMessage(0);
break;
}
return DefWindowProc(hWnd, message, wParam, lParam);
}
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEX wc;
wc.cbSize = sizeof(WNDCLASSEX);
wc.lpfnWndProc = (WNDPROC)WinProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = NULL;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = APPTITLE.c_str();
wc.hIconSm = NULL;
return RegisterClassEx(&wc);
}
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
window = CreateWindow(APPTITLE.c_str(), APPTITLE.c_str(), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 640, 480, NULL, NULL, hInstance, NULL);
if (window == 0) return 0;
ShowWindow(window, nCmdShow);
UpdateWindow(window);
device = GetDC(window);
return 1;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
MSG msg;
MyRegisterClass(hInstance);
if (!InitInstance(hInstance, nCmdShow)) return 0;
if (!Game_Init()) return 0;
while (!gameover)
{
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
Game_Run();
}
Game_End();
return msg.wParam;
}
请问为什么 不出结果，一闪而过，window为什么为空
