正则替换文本中重复的回车符换行符
/// <summary>
/// 替换重复的回车
/// </summary>
/// <param name="oldStr"></param>
/// <returns></returns>
public static string FilterRepeateEnter(string oldStr)
{
if (string.IsNullOrWhiteSpace(oldStr)) return oldStr;
return new Regex(@"(\r\n{1})\1{1,}").Replace(oldStr, "\r\n");
}