最近在自学API函数求大神帮忙看看这段代码中鼠标左键哪里到底哪里有问题？？？

#include
//
//int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
//{
// MessageBox(NULL, L"Goodbye crue world",L"cheng", MB_YESNOCANCEL);
//
//}
//

const LPCWSTR g_szClassName = {L"myWindowClass"};

// Step 4: 窗口过程
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_LBUTTONDOWN:
// BEGIN NEW CODE
{
//LPWSTR szFileName;
HINSTANCE hInstance = GetModuleHandle(NULL);
GetModuleFileName(hInstance, L"chengminglei", MAX_PATH);
MessageBox(hwnd, L"chengminglei", L"This program is:", MB_OK |
MB_ICONINFORMATION);
}
break;
// END NEW CODE
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;

}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
HWND hwnd;
MSG Msg;
//Step 1: 注册窗口类
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;

wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);

wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.lpszMenuName = NULL;
wc.lpszClassName = g_szClassName;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
if (!RegisterClassEx(&wc))
{
    MessageBox(NULL, L"Windows Registration Failed!!!", L"Error", MB_ICONEXCLAMATION | MB_OK);
    return 0;
}
// Step 2:创建窗口
hwnd = CreateWindowEx(
    WS_EX_CLIENTEDGE,
    //0,
    g_szClassName,
    L"相忘于江湖",
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT,
//  0,0,
    800, 500,
    NULL, NULL, hInstance, NULL);
if (hwnd == NULL)
{
    MessageBox(NULL, L"Window Creation Failed!", L"Error!",
        MB_ICONEXCLAMATION | MB_OK);
    return 0;
}
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
// Step 3: 消息循环
while (GetMessage(&Msg, NULL, 0, 0) > 0)
{
    TranslateMessage(&Msg);
    DispatchMessage(&Msg);
}
return Msg.wParam;

}

GetModuleFileName(hInstance, L"chengminglei", MAX_PATH);
这个API的第二个参数是输出参数，类型为LPTSTR，不能传递个const变量。建议楼主多看MSDN和调试。