問題描述

// 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，此代碼來自 Direct X 教程.

=============== I use CodeBlock, this code is from a Direct X tutorial.

我收到以下錯誤:

||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 ===|

推薦答案

你的項目沒有定義 UNICODE 預處理器符號，所以 Windows API 函數接受字符串指針需要 char* 而不是 wchar_t *.改變

Your project doesn't have the UNICODE preprocessor symbol defined, so Windows API functions that take pointers to strings expect char * and not wchar_t *. Change

L"WindowClass1"

到

"WindowClass1"

對剩余的字符串文字執行相同的操作.或者，將它們更改為 _T("WindowClass1")，這將根據定義的 UNICODE 符號擴展為正確類型的字符串文字.

Do the same for the remaining string literals. Alternatively, change them to _T("WindowClass1"), this will expand to the correct type of string literal based on the UNICODE symbol being defined.

我的建議是轉到您的項目屬性并將 Character Set 設置更改為 Unicode，然后顯式使用所有 Windows API 函數的寬字符版本.例如，調用 CreateWindowW 而不是 CreateWindow.

My recommendation is to go to your project properties and change the Character Set setting to Unicode, and then use the wide char versions of all Windows API functions explicitly. For example, instead of CreateWindow, call CreateWindowW.

我建議的項目設置僅適用于 Visual Studio，不確定如何在 Code::Blocks 中執行此操作.

The project setting I suggested only applies to Visual Studio, not sure how to do that in Code::Blocks.

這篇關于錯誤:無法在賦值中將“const wchar_t [13]"轉換為“LPCSTR {aka const char*}"的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！