Question

// include the basic windows header file
#include <windows.h>
#include <windowsx.h>

// the WindowProc function prototype LRESULT CALLBACK WindowProc(HWND hWnd,
                         UINT message,
                         WPARAM wParam,
                         LPARAM lParam);

// the entry point for any Windows program int WINAPI WinMain(HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine,
                   int nCmdShow) {
    // the handle for the window, filled by a function
    HWND hWnd;
    // this struct holds information for the window class
    WNDCLASSEX wc;

    // clear out the window class for use
    ZeroMemory(&wc, sizeof(WNDCLASSEX));

    // fill in the struct with the needed information
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WindowProc;
    wc.hInstance = hInstance;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
    wc.lpszClassName = L"WindowClass1";

    // register the window class
    RegisterClassEx(&wc);

    // create the window and use the result as the handle
    hWnd = CreateWindowEx(NULL,
                          L"WindowClass1",    // name of the window class
                          L"Our First Windowed Program",   // title of the window
                          WS_OVERLAPPEDWINDOW,    // window style
                          300,    // x-position of the window
                          300,    // y-position of the window
                          500,    // width of the window
                          400,    // height of the window
                          NULL,    // we have no parent window, NULL
                          NULL,    // we aren't using menus, NULL
                          hInstance,    // application handle
                          NULL);    // used with multiple windows, NULL

    // display the window on the screen
    ShowWindow(hWnd, nCmdShow);

    // enter the main loop:

    // this struct holds Windows event messages
    MSG msg;

    // wait for the next message in the queue, store the result in 'msg'
    while(GetMessage(&msg, NULL, 0, 0))
    {
        // translate keystroke messages into the right format
        TranslateMessage(&msg);

        // send the message to the WindowProc function
        DispatchMessage(&msg);
    }

    // return this part of the WM_QUIT message to Windows
    return msg.wParam; }

// this is the main message handler for the program LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    // sort through and find what code to run for the message given
    switch(message)
    {
        // this message is read when the window is closed
        case WM_DESTROY:
            {
                // close the application entirely
                PostQuitMessage(0);
                return 0;
            } break;
    }

    // Handle any messages the switch statement didn't
    return DefWindowProc (hWnd, message, wParam, lParam); }

=============== 我使用CodeBlock，这段代码来自Direct X教程。

我收到以下错误：

||In function 'int WinMain(HINSTANCE, HINSTANCE, LPSTR, int)':|
error: cannot convert 'const wchar_t [13]' to 'LPCSTR {aka const char*}' in assignment|
|49|warning: converting to non-pointer type 'DWORD {aka long unsigned int}' from NULL [-Wconversion-null]|
|49|error: cannot convert 'const wchar_t*' to 'LPCSTR {aka const char*}' for argument '2' to 'HWND__* CreateWindowExA(DWORD, LPCSTR, LPCSTR, DWORD, int, int, int, int, HWND, HMENU, HINSTANCE, LPVOID)'|
||=== Build finished: 2 errors, 1 warnings ===|

Answer 1

您的项目没有定义UNICODE预处理程序符号，因此Windows API函数指向期望char *而不是wchar_t *的字符串。改变

L"WindowClass1"

到

"WindowClass1"

对剩余的字符串文字执行相同的操作。或者，将它们更改为_T("WindowClass1")，这将根据定义的UNICODE符号扩展为正确的字符串文字类型。

我的建议是转到项目属性并将Character Set设置更改为Unicode，然后明确使用所有Windows API函数的宽字符版本。例如，代替CreateWindow，请致电CreateWindowW。

编辑：
我建议的项目设置仅适用于Visual Studio，不知道如何在Code :: Blocks中执行此操作。

Answer 2

1）如果要使用UNICODE进行编译，请更改选项。如果您是从IDE编译，请设置以下属性配置属性 - ＆gt;一般 - ＆gt;项目默认值 - ＆gt;字符集 - ＆gt;使用Unicode字符集。

如果从命令行编译，请使用选项/ DUNICODE / D_UNICODE

如果您不想使用UNICODE进行编译，请按照步骤2＆amp; 3下面。在字符集中，不要选择UNICODE。

2）之前

#include <windows.h>

添加

#include <tchar.h>

3）改变

wc.lpszClassName = L"WindowClass1";

到

wc.lpszClassName = _T("WindowClass1");

如果你想用UNICODE进行编译，你可以通过做＃1来完成，但最好做到所有3。

如果您想在没有UNICODE的情况下进行编译，请执行＃2＆amp; ＃3 - 不要做＃1。

Answer 3

我在单个源代码文件中使用它，因为我不想更改当前的项目配置

#ifndef UNICODE
#define UNICODE
#define UNICODE_WAS_UNDEFINED
#endif

#include <Windows.h>

#ifdef UNICODE_WAS_UNDEFINED
#undef UNICODE
#endif

错误：无法在赋值时将'const wchar_t [13]'转换为'LPCSTR {aka const char *}'

3 个答案: