C#一个判断子串在父串中出现的次数

/// <summary>
/// 计算字符串中子串出现的次数
/// </summary>
/// <param name=”str”>字符串</param>
/// <param name=”substring”>子串</param>
/// <returns>出现的次数</returns>
static int SubstringCount(string str, string substring)
{
if (str.Contains(substring))
{
string strReplaced = str.Replace(substring, “”);
return (str.Length – strReplaced.Length) / substring.Length;
}

return 0;
}
int count = SubstringCount(“ddddfdfhgfjghjhgjghjhjhjhjhj”, “gh”);