as 对象深度拷贝

 

这是一篇关于as3中对象深度拷贝的问题
今天自己总结下,便于大家参考

as3中通过ByteArray可以进行对象的深度拷贝
import flash.utils.ByteArray;
import flash.utils.getQualifiedClassName;
import flash.net.*;
import src.*;
function cloneObject(source:Object) :* {
var typeName:String = getQualifiedClassName(source);//获取全名
trace(”输出类的结构”+typeName);
//return;
var packageName:String = typeName.split(”::”)[0];//切出包名
trace(”类的名称”+packageName);
var type:Class = getDefinitionByName(typeName) as Class;//获取Class
trace(type);
registerClassAlias(packageName, type);//注册Class

//复制对象
var copier:ByteArray = new ByteArray();
copier.writeObject(source);
copier.position = 0;
return copier.readObject();
}

有的人说用复制对象那一段不就可以了吗，但是实际上行不通
对于数组深度复制来说， 复制对象的后面4句代码就足够了
var a1:Array=[1,2,3];

var a2:Array =cloneObject(a1);

var a3:Array = a1;
a1.push(”youmila”);
trace(”a1:”+a1+”a2:”+a2+”a3″+a3);

但是对于对象来说肯定不行

用列子测试下
src.youmila.as 代码：
package src{
public class youmila{
private var $_name:String =”youmila”;
private var $_num:Number =0;
public function youmila():void{
trace($_name);

}

public function secondFunc():void{
$_num++;
trace(”this a called function $_num::”+$_num);

}
}

}

yapollo.as 代码：

package {
public class yapollo{
private var $_name:String =”yapollo”;
public var $_num:Number =0;
public function yapollo():void{
trace($_name);

}
public function secondFunc():void{

$_num++;
trace(”this a called function $_num::”+$_num);

}

}
}

测试实例
var uml1:youmila = new youmila();
var uml2 = cloneObject(uml1);
trace(”类型”+getQualifiedClassName(uml2));

输出结果：
youmila
类型Object

原来的对象类型丢失了，所以对于对象而言，四行不够，必须
用registerClassAlias来保存类的别名，以用于丢失后恢复类的类型
测试实例
var uml1:youmila = new youmila();

var uml2 = cloneObject(uml1);
trace(”类型”+getQualifiedClassName(uml2));

var apollo:yapollo = new yapollo();

apollo.secondFunc();
var apollo2 = cloneObject(apollo);
trace(”第一次输出复制对象的$_num值”+apollo2.$_num);
trace(”类型”+getQualifiedClassName(apollo2));

apollo2.secondFunc();
trace(”第二次输出复制对象的$_num值”+apollo2.$_num);

输出结果：
youmila
输出类的结构src::youmila
类的名称src
[class youmila]
youmila
类型src::youmila
yapollo
this a called function $_num::1
输出类的结构yapollo
类的名称yapollo
[class yapollo]
yapollo
第一次输出复制对象的$_num值1
类型yapollo
this a called function $_num::2
第二次输出复制对象的$_num值2

 

package {
        import flash.utils.ByteArray;       
        import flash.utils.getQualifiedClassName;
        import flash.utils.getDefinitionByName;       
        import flash.net.registerClassAlias;


        public class CopyUtil{
                public static function clone(object:Object):Object{
                        var qClassName:String = getQualifiedClassName(object);
                        var objectType:Class = getDefinitionByName(qClassName) as Class;
                        registerClassAlias(qClassName, objectType);
                        var copier : ByteArray = new ByteArray();
                        copier.writeObject(object);
                        copier.position = 0;
                        return copier.readObject();
                }
        }
}

 

var instanceA : ClassA = new ClassA();
var instanceCopy : ClassA = CopyUtil.clone(instanceA ) as ClassA;
trace(instanceCopy == instanceA)//fale;
trace(instanceCopy  is ClassA) // true;
trace(instanceCopy is superClass) //true;

  

thanks:http://flexjs.cn/post/5.html