c++ - MSDN Windows App 教程问题

Question

我正在尝试按照介绍性教程创建您的第一个 Windows 应用程序。它说我应该有这个代码并且能够创建一个基本窗口。

#include <windows.h>
#include <stdlib.h>
#include <string.h>
#include <tchar.h>
#include <WinDef.h>


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


int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wcex;

wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style          = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc    = WndProc;
wcex.cbClsExtra     = 0;
wcex.cbWndExtra     = 0;
wcex.hInstance      = hInstance;
wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_APPLICATION));
wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName   = NULL;
wcex.lpszClassName  = szWindowClass;
wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_APPLICATION));

if (!RegisterClassEx(&wcex))
{
    MessageBox(NULL,
        _T("Call to RegisterClassEx failed!"),
        _T("Win32 Guided Tour"),
        NULL);

    return 1;
}

hInst = hInstance; // Store instance handle in our global variable

// The parameters to CreateWindow explained:
// szWindowClass: the name of the application
// szTitle: the text that appears in the title bar
// WS_OVERLAPPEDWINDOW: the type of window to create
// CW_USEDEFAULT, CW_USEDEFAULT: initial position (x, y)
// 500, 100: initial size (width, length)
// NULL: the parent of this window
// NULL: this application dows not have a menu bar
// hInstance: the first parameter from WinMain
// NULL: not used in this application
HWND hWnd = CreateWindow(
    szWindowClass,
    szTitle,
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT, CW_USEDEFAULT,
    500, 100,
    NULL,
    NULL,
    hInstance,
    NULL
);

if (!hWnd)
{
    MessageBox(NULL,
        _T("Call to CreateWindow failed!"),
        _T("Win32 Guided Tour"),
        NULL);

    return 1;
}

// The parameters to ShowWindow explained:
// hWnd: the value returned from CreateWindow
// nCmdShow: the fourth parameter from WinMain
ShowWindow(hWnd,
    nCmdShow);
UpdateWindow(hWnd);

// Main message loop:
MSG msg;
while (GetMessage(&msg, NULL, 0, 0))
{
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}

return (int) msg.wParam;


}

它告诉我 szClassName 未定义，hInst 未定义，szTile 已定义。我在这里遗漏了一些明显的东西吗？如果对“http://msdn.microsoft.com/en-us/library/bb384843.aspx”有帮助，这里是教程的链接。

Answer 1

嗯，错误说明了一切。在教程中看起来，他们是这样做的

static TCHAR szWindowClass[] = _T("win32app");
static TCHAR szTitle[] = _T("Win32 Guided Tour Application");

至于没有定义hInst，我不确定。尝试添加这两行，看看它是否有效。我想您会发现它只是忘记了这两行。

您还应该有一个 WndProc 函数，您可以这样简单地定义它:

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
 return DefWindowProc(hWnd, message, wParam, lParam);
}