flex StringUtil trim函数方法

public static function trim(str:String):String   { 
var startIndex:int = 0;      
while (isWhitespace(str.charAt(startIndex))) 
++startIndex;          
var endIndex:int = str.length - 1;   
while (isWhitespace(str.charAt(endIndex)))  
--endIndex;       
if (endIndex >= startIndex)    
return str.slice(startIndex, endIndex + 1);
else         
return "";  
} 


public static function isWhitespace(character:String):Boolean  {
switch (character)          {       
case " ":          
case "\t":  
case "\r":  
case "\n": 
case "\f":       
return true;     
default:               
return false;     
}   
} 

功能 截取两段的空格