c#判断是否数字

/// <summary>
    /// 判断是否数字
    /// </summary>
    public static bool CheckCharIsNum(string str)
    {
        string[] h = str.Split(‘.‘);
        bool falg = true;
        foreach (string item in h)
        {
            if (!System.Text.RegularExpressions.Regex.IsMatch(item, @"^\d+$"))
            {
                falg = false;
                break;
            }
        }
        return falg;
    }