如何序列化Vector。< Customobject&gt ;？ [英] How do I serialize Vector.<Customobject>?

问题描述

http://jacksondunstan.com/articles/1642 我一直跟随着T，但是我遇到了问题。我正在尝试保存一堆图标。它们具有一个自定义类 Iconn，并存储在 Vector。< Iconn> 中以备将来使用。用户添加新图标后，我将打开一个文件流，并使用它来写入整个矢量。

http://jacksondunstan.com/articles/1642 I followed this to the T, yet I'm running into issues. I'm trying to save a bunch of icons. They have a custom class "Iconn" and are stored in a Vector.<Iconn> for future use. Once the user adds a new icon, I open up a filestream and use it to write the entire vector.

        public function addShortcut(f:File):void
    {
        //Display on side
        icons.reverse(); //Add to the front so it displays on the top.
        icons.push(new Iconn(f)); //Use 16x16 bitmap

        addChild(icons[icons.length - 1]);
        icons.reverse();

        //Save object
        fs = new FileStream();
        fs.open(shortcuts, FileMode.WRITE);
        fs.writeObject(icons);
        fs.close();

        reorder(); //Reorganizes the icons on the screen.
    }

这一切正常，没有错误，但是当我尝试重新启动带有已保存图标的应用程序，矢量甚至不存在。

This works all and well with no errors, but when I try to re-launch the application with some icons saved, the vector doesn't even exist.

    icons = new Vector.<Iconn>();
    if (shortcuts.exists)
    {
        trace("Shortcuts exist..adding");
        fs = new FileStream();
        fs.open(shortcuts, FileMode.READ);
        icons = fs.readObject() as Vector.<Iconn>;
        fs.close();
        trace("icons = " + icons); //TypeError: Error #1009: Cannot access a property or method of a null object reference.
        trace("icons length  = " + icons.length); //TypeError: Error #1009: Cannot access a property or method of a null object reference.
    }

我尝试添加 registerClassAlias（ Vector。< Iconn>，Vector。< Iconn>）; ，但随后出现编译器错误
1067：类型为__AS3 __。vec的隐式强制转换：向量。到不相关类型的类。

I tried adding registerClassAlias("Vector.<Iconn>", Vector.<Iconn>);, but then I get a compiler error 1067: Implicit coercion of a value of type __AS3__.vec:Vector.<Iconn> to an unrelated type Class.

编辑：这是我的Iconn类 http://pastebin.com/5TujzpvR

Here is my Iconn class http://pastebin.com/5TujzpvR

推荐答案

1. 未序列化对象时，无法将参数传递给它们的构造函数。这意味着您要么需要删除嵌套在对象中的所有类的所有构造函数参数，要么通过为它们提供默认值来使它们全部可选。

1. When objects are unserialized, you cannot pass parameters to their constructors. This means that you either need to take out all constructor arguments of ALL classes nested inside your object, or make them all optional by giving them default values.

您必须注册要在要序列化的对象中使用的每个单个非基本类（包括对象的类本身）。这包括嵌套类。就您而言，至少包括：

You have to register every single non-primitive class you use in the object being serialized (including the object's class itself). This includes nested classes. In your case, this includes at least:

flash.display.Bitmap;
flash.display.Sprite;
flash.events.MouseEvent;
flash.filesystem.File;
fl.transitions.Tween;
fl.transitions.easing.Strong;

加上在这些类中引用的任何内容。

Plus anything referenced inside of those classes.

对显示对象进行序列化是行不通的*（从技术上来说，使用实现 IExternalizable ，但这确实涉及到）。如果您想要一个示例，请在此处。

Serializing display objects just doesn't work* (it is technically possible with a custom class that implements IExternalizable, but it's quite involved). If you want an example, there is one here.

---

序列化显示对象的最佳方法是创建一个非常基本的类，其中包含重建显示所需的最少数据

---

The best way to serialize display objects, is to create a very very basic class that contains the bare minimum data needed to reconstruct your display object.

在您看来，您真正需要的只是位图数据。因此，您可以制作一个像下面这样的简单类：

In your case, it looks like all you really need is bitmap data. So you could make a simple class like the following:

package 
{
    import flash.geom.Rectangle;
    import flash.utils.ByteArray;

    public class SaveData 
    {
        public var imgBytes:ByteArray;
        public var bounds:Rectangle;
        public var transparent:Boolean;
    }
}

所有存储的都是原始位图数据（一个字节像素值数组）和位图的边界。

All it stores is the raw bitmap data (a byte array of pixel values), and bounds of the bitmap.

首先，您需要注册所有使用的类。看起来像这样：

First, you need to register all the classes used. That would look like this:

        //you need to register your class that you're using writeObject on
        registerClassAlias("SaveData", SaveData); 

        //you also need to register the two classes that are referenced in your SaveData class
        registerClassAlias("flash.utils.ByteArray", ByteArray);
        registerClassAlias("flash.geom.Rectangle", Rectangle);

        //you ALSO need to register Point since it's referenced inside the Rectangle class
        registerClassAlias("flash.geom.Point", Point);

现在，要保存它，请执行大部分已经在做的事情：

Now, to save it, do mostly what you're already doing:

//create a vector to store your list of items to save
var saveArray:Vector.<SaveData> = new Vector.<SaveData>();

//loop through all your icons and do the following in the loop (where bitmap is the icon's bitmap):

var saveData:SaveData = new SaveData();
saveData.bounds = bitmap.getBounds(bitmap);
saveData.imgBytes = bitmap.bitmapData.getPixels(saveData.bounds);
saveData.transparent = bitmap.bitmapData.transparent;
saveArray.push(saveData);

//write the Vector to the file
fs = new FileStream();
fs.open(shortcuts, FileMode.WRITE);
fs.writeObject(saveArray);
fs.close();

现在，当您准备将其全部加载回去时：

Now, when you're ready to load it all back in:

fs = new FileStream();
fs.open(shortcuts, FileMode.READ);
var saveArray:Vector.<SaveData> = fs.readObject() as Vector.<SaveArray>;
fs.close();

//now loop through your array and re-create all your icons.

for(var i:int=0;i<saveArray.length;i++){
    var bmd:BitmapData = new BitmapData(saveArray[i].bounds.width, saveArray[i].bounds.height, saveArray[i].transparent);
    bmd.setPixels(saveArray[i].bounds, saveArray[i].imgBytes);

    var bitmap:Bitmap = new Bitmap(bmd);

    //instead of passing in a file to your Iconn class, tweak it so you pass in a bitmap:
    var icon:Iconn = new Iconn(bitmap);

    //do what you need to do with he icon
}

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