winapi - 如何从 HICON 确定图标的大小？

Question

我有一个由 HICON 标识的图标我想以自定义控件为中心绘制的句柄。

如何确定图标的大小以便计算正确的绘图位置？

Answer 1

这是一个 C++ 版本的代码:

struct MYICON_INFO
{
    int     nWidth;
    int     nHeight;
    int     nBitsPerPixel;
};

MYICON_INFO MyGetIconInfo(HICON hIcon);

// =======================================

MYICON_INFO MyGetIconInfo(HICON hIcon)
{
    MYICON_INFO myinfo;
    ZeroMemory(&myinfo, sizeof(myinfo));

    ICONINFO info;
    ZeroMemory(&info, sizeof(info));

    BOOL bRes = FALSE;

    bRes = GetIconInfo(hIcon, &info);
    if(!bRes)
        return myinfo;

    BITMAP bmp;
    ZeroMemory(&bmp, sizeof(bmp));

    if(info.hbmColor)
    {
        const int nWrittenBytes = GetObject(info.hbmColor, sizeof(bmp), &bmp);
        if(nWrittenBytes > 0)
        {
            myinfo.nWidth = bmp.bmWidth;
            myinfo.nHeight = bmp.bmHeight;
            myinfo.nBitsPerPixel = bmp.bmBitsPixel;
        }
    }
    else if(info.hbmMask)
    {
        // Icon has no color plane, image data stored in mask
        const int nWrittenBytes = GetObject(info.hbmMask, sizeof(bmp), &bmp);
        if(nWrittenBytes > 0)
        {
            myinfo.nWidth = bmp.bmWidth;
            myinfo.nHeight = bmp.bmHeight / 2;
            myinfo.nBitsPerPixel = 1;
        }
    }

    if(info.hbmColor)
        DeleteObject(info.hbmColor);
    if(info.hbmMask)
        DeleteObject(info.hbmMask);

    return myinfo;
}