关于无法创建w32窗口的问题

#include
#include

LRESULT _stdcall WndProc (HWND, UINT, WPARAM, LPARAM);

int _stdcall _tWinMain ( HINSTANCE hInstance, HINSTANCE hPrevInstance, PTSTR szCmdLine, int iCmdShow)
{
WNDCLASSEX wndClassEx;
wndClassEx.cbSize = sizeof(WNDCLASSEX);
wndClassEx.style = CS_HREDRAW | CS_VREDRAW;
wndClassEx.lpfnWndProc = WndProc;
wndClassEx.cbClsExtra = 0;
wndClassEx.cbWndExtra = 0;
wndClassEx.hInstance = hInstance;
wndClassEx.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wndClassEx.hCursor = LoadCursor (NULL,IDC_ARROW);
wndClassEx.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH);
wndClassEx.lpszMenuName = NULL;
wndClassEx.lpszClassName = L"SimWinClass";
wndClassEx.hIconSm = NULL;

if(!RegisterClassEx(&wndClassEx))
{
    MessageBox(NULL,L"注册窗口类失败！",L"SimpleWinApp",0);
    return 0;
}


HWND hwnd = NULL;
hwnd = CreateWindowEx( NULL,
    L"SimWinApp",
    L"SimpleWinApp",
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT,
    CW_USEDEFAULT,
    CW_USEDEFAULT,
    CW_USEDEFAULT,
    NULL,
    NULL,
    hInstance,
    NULL
    );

if(hwnd == NULL)
{
    MessageBox(NULL, L"创建窗口失败", L"SimpleWinApp",0);
    return 0;
}

ShowWindow( hwnd, iCmdShow );
UpdateWindow( hwnd );

MSG msg;
while( GetMessage( &msg, NULL, 0, 0))
{
    TranslateMessage( &msg );
    DispatchMessage( &msg );
}
return msg.wParam ;

}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wparam, LPARAM lParam)
{
switch (message)
{
case WM_CREATE:
break;

case WM_KEYDOWN:
    if( wparam == VK_ESCAPE)
        PostQuitMessage (0);
    break;

case WM_DESTROY:
    PostQuitMessage (0);
    break;
}
return DefWindowProc(hwnd, message, wparam, lParam);

}

代码如上，基础窗口创建显示创建失败，句柄无法获取，求解答

用WINAPI，别用_stdcall，64位的WINAPI是_fastcall

另外关于win32创建窗口：
http://blog.csdn.net/zuishikonghuan/article/details/46378475

CreatWindowEx()里的窗口类名写错了。