去掉字符串中非法字符包括轉義字符和全國字符

//非法字符自定義
  private string Get_Format_Custorm(string str1)
  {
   string rel_str="";

//   String str1 = "　　/r/n　　/r/n　　/r/n多幅阿斗所附斯多　　/r/n夫嘎的從";
    String delim = "　/r/n ";//自定義去掉的字符
//   String str2 = str1.Trim(delim.ToCharArray());
   int startIndex=0;

   while(startIndex<str1.Length)
   {
    str1 = str1.Trim(delim.ToCharArray());
    int endIndex=str1.IndexOfAny(delim.ToCharArray(),startIndex);

    if(endIndex!=-1)
    {
     rel_str+=str1.Substring(startIndex,endIndex-startIndex);
     str1=str1.Substring(endIndex+1);
     
    }
    else
    {
     rel_str+=str1.Substring(startIndex);
     break;
    }
   }
   return rel_str;
  }