幻鲨的天空

function Escape(strS:String):String
{
      var iCount:Number;
      var strD:String;
      var strChar:String;
      var iChar:Number;
//数字对应的字符     

      var arrHex:Array=new Array("0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F");
      strD="";
      for(iCount=0;iCount<strS.length;iCount++)
      {
            strChar=strS.charAt(iCount);
            if(strChar==" ")
                  strD+=" ";
//不变的字符      

            else if(("A"<=strChar && strChar<="Z") || ("a"<=strChar && strChar<="z") || ("0"<=strChar && strChar<="9"))
                  strD+=strChar;
            else if (strChar=="-" || strChar=="_" || strChar=="." || strChar=="*" || strChar=="+" || strChar=="/")
                  strD+=strChar;
//小于127的应该被编码的字符           

            else if(strChar.charCodeAt(0)<0x007f)
            {
                  strD+="%";
                  iChar=strChar.charCodeAt(0);
//由于arrHex数组只有16个数字对应的字符，因此一个字节要分成两部分

//>>>为简单右移                 

                  strD+=arrHex[iChar>>>4];
                  strD+=arrHex[iChar & 0x000f];
            }
//其它的字符           

            else
            {
//两个字节要分成四个部分处理                 

                  strD+="%u";
                  iChar=strChar.charCodeAt(0);
                  strD+=arrHex[iChar>>>12];
                  strD+=arrHex[(iChar & 0x0f00)>>>8];
                  strD+=arrHex[(iChar & 0x00f0)>>>4];
                  strD+=arrHex[iChar & 0x000f];
            }
      }
      delete arrHex;
      return strD;
}

转自http://xialulee.spaces.live.com/blog/cns!4EE324C8ACFA82DB!333.entry?wa=wsignin1.0&sa=497639255