字符串截取小数点后面的零

string str = "12.0000";

            string str1 = str.Substring(str.Length - 4, 4);

            if (str1.CompareTo("0000") > 0)
            {
                Response.Write(str);
            }
            else
            {
                Response.Write(str.Substring(0, str.Length - 5));
            }

string str = "12.0000";

            string str1 = str.Substring(str.Length - 4, 4);

            if (str1.Substring(3, 1).CompareTo("0") > 0)
            {
                Response.Write(str);
            }
            else if (str1.Substring(2, 1).CompareTo("0") > 0)
            {
                Response.Write(str.Substring(0, str.Length - 1));
            }
            else if (str1.Substring(1, 1).CompareTo("0") > 0)
            {
                Response.Write(str.Substring(0, str.Length - 2));
            }
            else if (str1.Substring(0, 1).CompareTo("0") > 0)
            {
                Response.Write(str.Substring(0, str.Length - 3));
            }
            else
            {
                Response.Write(str.Substring(0, str.Length - 5));
            }

//格式化电子化移交完成率保留两位
    public String formateRate(String rateStr){
         if(rateStr.indexOf(".") != -1){
             //获取小数点的位置
             int num = 0;
             num = rateStr.indexOf(".");

             //获取小数点后面的数字是否有两位不足两位补足两位
             String dianAfter = rateStr.substring(0,num+1);
             String afterData = rateStr.replace(dianAfter, "");
             if(afterData.length() < 2){
                afterData = afterData + "0" ;
             }else{
                 afterData = afterData;
             }
             return rateStr.substring(0,num) + "." + afterData.substring(0,2);
          }else{
            if(rateStr == "1"){
               return "100";
            }else{
                return rateStr;
            }
          }
    }