AS3 深度拷贝对象的构造函数带参数

     关于AS3的深度拷贝, 网站有不少的的文章介绍.  我在EncryptZip项目中也用到了, 由于ZipEntry 有自己的构造函数, 在copier.readObject()处得到了参数个数不匹配错误(ArgumentError: Error #1063),  所以查找了相关资料, 然而最终也没有找到一个好的解决方案.  

    资料显示:如果不使用registerClassAlias注册类的别名, 会丢失对象的类型信息, 在类型转换时候会有强制类型错误(TypeError: Error #1034:).  

     无奈只好用了一个折衷的方法:

 1. 注释registerClassAlias, 增加fill方法. (丢失类型信息, 返回Object对象)

 

     package com.universalmind.cairngorm.vo { import flash.utils.ByteArray; /* import flash.utils.getQualifiedClassName; import flash.utils.getDefinitionByName; import flash.net.registerClassAlias; */ public class ValueObject { public function ValueObject() { } /*TypeError: Error #1034: *when the sub-class of ValueObject has a special constructor definitions, * #1034 will happen during performs copier.readObject() after used registerClassAlias */ public function clone():Object { /* var typeName:String = getQualifiedClassName(this); var packageName:String = typeName.split("::")[0]; var type:Class = getDefinitionByName(typeName) as Class; registerClassAlias(packageName, type); */ var copier:ByteArray = new ByteArray(); copier.writeObject(this); copier.position = 0; return copier.readObject(); } public function fill(obj:Object):void { for (var key:String in obj) { this[key] = obj[key]; } } } } 

          完整代码  Refer  to: http://code.google.com/p/encrypt-zip-as3-java/source/browse/trunk/EncryptZip/flex_src/com/universalmind/cairngorm/vo/ValueObject.as 

 

 2. 在ZipEntry里override了clone方法, (使用Object的属性name, 实例化ZipEntry, 赋值并返回ZipEntry对象)

     [Bindable] public class ZipEntry extends com.universalmind.cairngorm.vo.ValueObject{ // some members are internal as ZipFile will need to set these directly // where their accessor does type conversion private var _name:String; private var _size:int = -1; private var _compressedSize:int = -1; private var _crc:uint; /** @private */ private var _dostime:uint; private var _method:int = -1; // compression method private var _extra:ByteArray; // optional extra field data for entry private var _comment:String; // optional comment string for entry // The following flags are used only by ZipOutput /** @private */ private var _flag:int; // bit flags /** @private */ private var _version:int; // version needed to extract /** @private */ private var _offset:int; // offset of loc header /** * Creates a zip entry with the given name. * @param name the name. May include directory components separated * by '/'. */ public function ZipEntry(name:String) { _name = name; } ...省略代码... ...省略代码... /* *fix error:ArgumentError: Error #1063 * */ public override function clone():Object { var clone:Object = super.clone(); var entry:ZipEntry = new ZipEntry(clone.name); entry.fill(clone); return entry; } 

    完整代码  Refer  to: http://code.google.com/p/encrypt-zip-as3-java/source/browse/trunk/EncryptZip/flex_src/nochump/util/zip/ZipEntry.as

 

3. 补充:

    实现的方式类似copyFrom(src:*):*, 但不同.  在Java中用二进制流的形式将对象深度拷贝成功, 那是因为Java每个对象都有默认的无参构造函数, 而AS3却不支持对象有多个构造函数.

 

(转贴注明出处)

 

Author:David

    Mail:xiang.okay@gmail.com