android序列化(2)Parcelable与Parcel

1.简介

Parcel  ：　　包裹

　　Android采用这个它封装消息数据。这个是通过IBinder通信的消息的载体。需要明确的是Parcel用来存放数据的是内存（RAM），而不是永久性介质（Nand等）。

Parcelable：　可放入包裹的协议接口

　　如果需要封装到包裹中去，就必须实现这一接口，实现了这一接口，该实体就成为“可打包的”了。

2.示例

 import android.content.Intent;

 import android.os.Parcel;

 import android.os.Parcelable;

 import com.e.weixin.R;

 import com.e.weixin.contacts.beans.ContactBean;

 public class MsgBean implements Parcelable{

     public static final int MSB_TYPE_TXT = ;

     public static final int MSB_TYPE_TP = ;

     public static final int MSB_TYPE_XSP = ;

     public static final int MSB_TYPE_HB = ;

     public static final int MSB_TYPE_ZZ = ;

     public static final int MSB_TYPE_SC = ;

     public static final int MSB_TYPE_WZ = ;

     public static final int MSB_TYPE_SPLT = ;

     public static final int MSB_TYPE_MP = ;

     public static final int MSB_TYPE_YY = ;

     ContactBean contact;

     public int type ;

     public String title;

     public String content;

     public int icon;

     public int movie_res;

     //==================

     public MsgBean(){

     }

     //下面代码都是as自动生成

     protected MsgBean(Parcel in) {

         //从Parcel中读一个实现了Parcelable接口的自定义的类，需要ClassLoader

         contact = in.readParcelable(ContactBean.class.getClassLoader());

         type = in.readInt();

         title = in.readString();

         content = in.readString();

         icon = in.readInt();

         movie_res = in.readInt();

     }

     public static final Creator<MsgBean> CREATOR = new Creator<MsgBean>() {

         @Override

         public MsgBean createFromParcel(Parcel in) {

             return new MsgBean(in);

         }

         @Override

         public MsgBean[] newArray(int size) {

             return new MsgBean[size];

         }

     };

     @Override

     public int describeContents() {

         return ;

     }

     @Override

     public void writeToParcel(Parcel dest, int flags) {

         dest.writeParcelable(contact,flags);//写另一个自定义的类，它也实现了Parcelable接口

         dest.writeInt(type);

         dest.writeString(title);

         dest.writeString(content);

         dest.writeInt(icon);

         dest.writeInt(movie_res);

     }

     public static void test(){

         int sz = -,position = -;

         //1,准备一个Parcel,其它数据放入其中

         Parcel parcel = Parcel.obtain();

         sz = parcel.dataSize();

         position = parcel.dataPosition();

         //2,准备要写入的对象，其中包含另一个实现了Parcelable的对象

         ContactBean cb = new ContactBean();

         cb.name = "name";

         cb.sectionCount = ;

         cb.isSection = true;

         cb.icon = R.drawable.ebf;

         MsgBean mb1 = new MsgBean();

         mb1.type = ;

         mb1.icon = R.drawable.ebf;

         mb1.content = "content";

         mb1.title = "title";

         mb1.contact = cb;

         mb1.movie_res = R.raw.movie;

         //3,写入

         mb1.writeToParcel(parcel,);

         sz = parcel.dataSize();

         position = parcel.dataPosition();

         //4,读取

         MsgBean mb2 = MsgBean.CREATOR.createFromParcel(parcel);

         MsgBean mb3 = parcel.readParcelable(MsgBean.class.getClassLoader());

         parcel.writeParcelable(mb1, );

         MsgBean mb4 = MsgBean.CREATOR.createFromParcel(parcel);

         MsgBean mb5 = parcel.readParcelable(MsgBean.class.getClassLoader());

         //5,开始序列

         Intent intent = new Intent();

         intent.putExtra("parcelable",mb1);

         intent.putExtra("int",);

         //6,开始反序列

         //通常是在另一个地方得到上面的Intent

         MsgBean mb6 = intent.getParcelableExtra("parcelable");

         int data = intent.getIntExtra("int",-);

     }

 }