AS函数的一些特殊应用

1. 根据数字决定调用函数个数，并动态给对象赋属性

package { 
    import flash.display.Sprite; 
    public class Sample9261 extends Sprite 
    {    
        public function Sample9261() 
        { 
            var arr:Array = new Array(); 
            arr.push(aFunc); 
            arr.push(bFunc); 
            arr.push(cFunc); 
             
            var obj:Object = new Object(); 
             
            for(var i:uint=0;i<arr.length;i++) 
            { 
                arr[i](obj); 
            } 
             
            for(var j:String  in  obj) 
            { 
                trace(j+":"+obj[j]); 
            } 
             
            for each(var k:String  in  obj) 
            { 
                trace(k); 
            } 
        } 
         
        private function aFunc(obj:Object):void 
        { 
            obj.attribute1 = true; 
            trace("执行了aFunc方法"); 
        } 
         
        private function bFunc(obj:Object):void 
        { 
            obj.attribute2 = true; 
            trace("执行了bFunc方法"); 
        } 
         
        private function cFunc(obj:Object):void 
        {
            obj.attribute3 = true; 
            trace("执行了cFunc方法"); 
        } 
    } 
}

2. 动态改变函数调用顺序

package { 
    import flash.display.Sprite; 
    public class Sample9261 extends Sprite 
    {    
        public function Sample9261() 
        { 
            var arrIndex:Array = [2,0,1]; 
            var arrFunc:Array =  new Array(); 
            arrFunc.push(aFunc); 
            arrFunc.push(bFunc); 
            arrFunc.push(cFunc); 
                 
            for(var i:uint=0;i<arrIndex.length;i++) 
            { 
                arrFunc[arrIndex[i]](); 
            } 
        } 
         
        public function aFunc():void 
        { 
            trace("this  is  a function"); 
        } 
         
        public function bFunc():void 
        { 
            trace("this  is  b function"); 
        } 
         
        public function cFunc():void 
        { 
            trace("this  is  c function"); 
        } 
    } 
}

3. 利用函数返回函数

package { 
    import flash.display.Sprite; 
    public class Sample9261 extends Sprite 
    {    
        public function Sample9261() 
        { 
            //通过A调用只有一个参数的aFunc(): 
            chooseFuncBy("A")("A func has only one parameter."); 
            //输出：aFunc():A func has only one parameter. 
             
            //通过B调用有两个参数的bFunc(): 
            chooseFuncBy("B")("B func has two parameters.","No.2 parameter"); 
            //输出:bFunc():B func has two parameters. one more Parameter:No.2 parameter 
             
            //字符串不符,默认函数 
         chooseFuncBy("wu lala")("I choose A function"); 
            //输出：Welcome to kingda.org! My blog 
             
            var withObj:Object = new Object(); 
            var myObj:Object = {name:"黑羽",blog:"http://www.kingda.org",hobby:"WowCraft"}; 
            chooseFuncBy(withObj)(myObj); 
            /*输出： 
        objectFunc(): 
            name:黑羽 
        blog:http://www.kingda.org 
            hobby:WowCraft 
            */ 
        } 
         
        public function chooseFuncBy(input:*):Function 
        { 
            //运用一：利用参数的种类来确定返回的函数 
         if(!(input  is  String)) 
            { 
                return objectFunc; 
            } 
             
             //运用二：根据参数内容来返回函数 
         switch(input) 
            { 
                case "A": 
                return aFunc; 
                case "B": 
                return bFunc; 
                default: 
                return kingdaFunc; 
            } 
             
           //更多延伸运用：利用参数个数、 is 确定不同Class的实例来选择函数，等等 
        } 
        public function aFunc(str:String):void 
        { 
            trace("aFunc():"+str); 
        } 
         
        public function bFunc(str1:String,str2:String):void 
        { 
            trace("bFunc():"+str1+" one more Parameter:"+str2); 
        } 
         
        public function kingdaFunc(...rest):void 
        { 
            trace("Welcome to Kingda.org! My blog"); 
        } 
         
        public function objectFunc(kingdaObj:Object):void 
        { 
            trace("objectFunc():"); 
            for(var i:String  in  kingdaObj) 
            { 
                trace(i+":"+kingdaObj[i]); 
            } 
        } 
    } 
}

4. 函数动态添加属性(可以得到该函数被调用次数)

package { 
    import flash.display.Sprite; 
    public class Sample9261 extends Sprite 
    {    
        public function Sample9261() 
        { 
            var shot:Function = function():void
            { 
                shot["times"]++; 
                trace("Shot():time:"+shot["times"]); 
            } 
             
            shot["times"] = 0; //初始化times 
            shot(); //输出:Shot():times:1 
            shot(); //输出:Shot():times:2 
            shot(); //输出:Shot():times:3 
        } 
    } 
}

5. 函数对象动态添加实例方法

package { 
    import flash.display.Sprite; 
    public class Sample9261 extends Sprite 
    {    
        public function Sample9261() 
        { 
            var shot:Function = function():void 
            { 
                shot["times"]++; 
                trace("Shot():times:"+shot["times"]); 
                shot["reload"](); 
                //其它代码 
            } 
             
            shot["times"] = 0;//初始化times 
             
            shot["reload"] = function():void 
            { 
                trace("reload:"+this["times"]); 
                if(this["times"]>3) 
                { 
                    this["times"] = 0; 
                } 
            } 
             
            shot["reload"](); 
            shot(); 
            shot(); 
            shot(); 
            shot(); 
            shot(); 
            shot(); 
        } 
    } 
}

6. 动态改变实例里面的方法实现

MyClass.as

package Model 
{ 
    public class MyClass 
    { 
        public function MyClass() 
        { 
        } 
         
        public var AlertFunc:Function = function():void 
        { 
            trace("what time  is  it now?"); 
        } 
    } 
}

Sample9271.as

package { 
    import flash.display.Sprite; 
    import Model.MyClass; 
    public class Sample9271 extends Sprite 
    { 
        public function Sample9271() 
        { 
            var model:MyClass = new MyClass(); 
            model.AlertFunc(); 
            model.AlertFunc = AMFunc; 
            model.AlertFunc(); 
            model.AlertFunc = PMFunc; 
            model.AlertFunc(); 
        } 
         
        internal function AMFunc():void 
        { 
            trace("Good Morning"); 
        } 
         
        internal function PMFunc():void 
        { 
            trace("Good Afternoon"); 
        } 
    } 
}