用vc画图为了让x坐标上各数值的位置右对齐用TextOut使用了GetTextExtent函数来获得坐标值的字符串长度。当把图复制到剪贴板时相当于在剪贴板里画这个函数返回的坐标字符串长度就不正确提供正确的完整代码

以下是一个示例代码，可以在使用GetTextExtent函数时进行调整，以在剪贴板中正确显示字符串长度：

#include <Windows.h>
#include <string>

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hWnd, &ps);

        // 设置字体
        HFONT hFont = CreateFont(16, 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS,
            CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH | FF_SWISS, L"Arial");
        SelectObject(hdc, hFont);

        // 绘制坐标轴
        MoveToEx(hdc, 50, 50, NULL);
        LineTo(hdc, 50, 250);
        LineTo(hdc, 350, 250);

        // 绘制坐标轴刻度和标签
        for (int i = 0; i <= 10; i++)
        {
            int x = 50 + i * 30;
            int y = 250;
            MoveToEx(hdc, x, y, NULL);
            LineTo(hdc, x, y + 5);

            // 获取坐标字符串长度
            std::wstring str = std::to_wstring(i * 10);
            SIZE size;
            GetTextExtentPoint32(hdc, str.c_str(), str.length(), &size);

            // 右对齐坐标标签
            TextOut(hdc, x - size.cx / 2, y + 10, str.c_str(), str.length());
        }

        EndPaint(hWnd, &ps);
        break;
    }
    case WM_COPY:
    {
        // 创建内存设备上下文
        HDC hdc = GetDC(hWnd);
        HDC hMemDC = CreateCompatibleDC(hdc);
        HBITMAP hBitmap = CreateCompatibleBitmap(hdc, 400, 300);
        SelectObject(hMemDC, hBitmap);

        // 绘制图像
        SendMessage(hWnd, WM_PRINTCLIENT, (WPARAM)hMemDC, PRF_CLIENT);

        // 将图像复制到剪贴板
        OpenClipboard(hWnd);
        EmptyClipboard();
        SetClipboardData(CF_BITMAP, hBitmap);
        CloseClipboard();

        // 释放资源
        DeleteDC(hMemDC);
        ReleaseDC(hWnd, hdc);

        break;
    }
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // 注册窗口类
    WNDCLASSEX wcex;
    memset(&wcex, 0, sizeof(wcex));
    wcex.cbSize = sizeof(wcex);
    wcex.style = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc = WndProc;
    wcex.hInstance = hInstance;
    wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
    wcex.lpszClassName = L"MyWndClass";
    RegisterClassEx(&wcex);

    // 创建窗口
    HWND hWnd = CreateWindow(L"MyWndClass", L"VC画图示例", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
        400, 300, NULL, NULL, hInstance, NULL);
    if (!hWnd)
    {
        return FALSE;
    }

    // 显示窗口
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);

    // 消息循环
    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }

    return (int)msg.wParam;
}
``