[Windows][C++]让窗口居中

- 日理万妓 2022-09-16 08:58 248阅读 0赞

#include <Windows.h>
    #include <memory>
    #include <string>
    #include <crtdbg.h>
    
    class WindowException:public std::exception
    { 
        std::string str{ };
    public:
    
        WindowException(_In_ std::string str):str(std::move(str))
        { 
            
        }
    
        // 不应该忽略该返回值
        [[nodiscard("Exception info function")]]
        const char* what() const noexcept override
        { 
            return this->str.c_str();
        }
    };
    
    auto CenterWindowF(_In_ const HWND& winHandle) -> void
    { 
        if (!winHandle)
            throw WindowException{  "Error:No Window handle" };	// 窗口句柄不应为空
    
        RECT rect{ };
        GetWindowRect(winHandle, &rect);
    
        const auto width{  rect.right - rect.left };
        const auto height{  rect.bottom - rect.top };
    
        const auto cx{  GetSystemMetrics(SM_CXFULLSCREEN) }; // 取显示器屏幕高宽
        const auto cy{  GetSystemMetrics(SM_CYFULLSCREEN) };
    
        const auto x{  cx / 2 - width / 2 };
        const auto y{  cy / 2 - height / 2 };
    
        MoveWindow(winHandle, x, y, width, height,false); // 移动窗口位置居中
    }
    
    auto WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _In_ LPSTR lpCmdLine, _In_ int nShowCmd) -> int
    { 
        constexpr auto winTitle{  L"Hello - Windows" };
        const auto winHandle{  FindWindow(nullptr,L"Debug") }; // 获取窗口句柄
    
        switch (const auto i{  MessageBox(winHandle, L"You need change window to center?", winTitle, MB_YESNOCANCEL | MB_ICONQUESTION | MB_TOPMOST ) }; i)
        { 
        case IDOK:
            MessageBox(winHandle, L"You click Ok button", winTitle, MB_OK);
            break;
        case IDYES:
            try
            { 
                CenterWindowF(winHandle);
            }
            catch (WindowException& winexc)
            { 
                OutputDebugStringA("----------------------\n");
                OutputDebugStringA(winexc.what());
                OutputDebugStringA("\n----------------------\r\n");
            }
            SetWindowText(winHandle, L"Center!!!!");
            MessageBox(winHandle, L"Changed", winTitle, MB_OK);
            break;
        case IDNO:
            MessageBox(winHandle, L"Unchanged", winTitle, MB_OK);
            break;
        case IDCANCEL:
            MessageBox(winHandle, L"Cancel", winTitle, MB_OK);
            break;
        default:
            break;
        }
    
        _CrtDumpMemoryLeaks();	// 检查内存泄漏
        return 0;
    }