判断文件是否被打开

    [DllImport("kernel32.dll")]
    public static extern IntPtr _lopen(string lpPathName, int iReadWrite);

    [DllImport("kernel32.dll")]
    public static extern bool CloseHandle(IntPtr hObject);
    public const int OF_READWRITE = 2;
    public const int OF_SHARE_DENY_NONE = 0x40;
    public static readonly IntPtr HFILE_ERROR = new IntPtr(-1);

    /// <summary>
    /// 文件是否被打开
    /// </summary>
    /// <param name="path"></param>
    /// <returns></returns>
    public static bool IsFileOpen(string path)
    {
        if (!File.Exists(path))
        {
            return false;
        }
        IntPtr vHandle = _lopen(path, OF_READWRITE | OF_SHARE_DENY_NONE);
        if (vHandle == HFILE_ERROR)
        {
            return true;
        }
        CloseHandle(vHandle);
        return false;
    }