JS ArrayBuffer和String

http://blog.mn886.net/chenjianhua/show/6b02fa4173ed/index.html

ArrayBuffer和String 互相转换

 function str2ab(str){
     var buf = new ArrayBuffer(str.length*2);
     bufView = new Uint16Array(buf);
     for(var i=0; i<str.length; i++){
         bufView[i] = str.charCodeAt(i);
     }
     return buf;
 }
 function ab2str(buf){
     return String.fromCharCode.apply(null, new Uint16Array(buf));
 }