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 

  1 import android.content.Intent;
  2 import android.os.Parcel;
  3 import android.os.Parcelable;
  4 
  5 import com.e.weixin.R;
  6 import com.e.weixin.contacts.beans.ContactBean;
  7 
  8 public class MsgBean implements Parcelable{
  9 
 10     public static final int MSB_TYPE_TXT = 0;
 11     public static final int MSB_TYPE_TP = 1;
 12     public static final int MSB_TYPE_XSP = 2;
 13     public static final int MSB_TYPE_HB = 3;
 14     public static final int MSB_TYPE_ZZ = 4;
 15     public static final int MSB_TYPE_SC = 5;
 16     public static final int MSB_TYPE_WZ = 6;
 17     public static final int MSB_TYPE_SPLT = 7;
 18     public static final int MSB_TYPE_MP = 8;
 19     public static final int MSB_TYPE_YY = 9;
 20 
 21 
 22     ContactBean contact;
 23     public int type ;
 24     public String title;
 25     public String content;
 26     public int icon;
 27     public int movie_res;
 28 
 29 
 30 
 31 
 32     //==================
 33     public MsgBean(){
 34 
 35     }
 36 
 37     //下面代码都是as自动生成
 38     protected MsgBean(Parcel in) {
 39         //从Parcel中读一个实现了Parcelable接口的自定义的类，需要ClassLoader
 40         contact = in.readParcelable(ContactBean.class.getClassLoader());
 41         type = in.readInt();
 42         title = in.readString();
 43         content = in.readString();
 44         icon = in.readInt();
 45         movie_res = in.readInt();
 46     }
 47 
 48     public static final Creator<MsgBean> CREATOR = new Creator<MsgBean>() {
 49         @Override
 50         public MsgBean createFromParcel(Parcel in) {
 51             return new MsgBean(in);
 52         }
 53 
 54         @Override
 55         public MsgBean[] newArray(int size) {
 56             return new MsgBean[size];
 57         }
 58     };
 59 
 60     @Override
 61     public int describeContents() {
 62         return 0;
 63     }
 64 
 65     @Override
 66     public void writeToParcel(Parcel dest, int flags) {
 67         dest.writeParcelable(contact,flags);//写另一个自定义的类，它也实现了Parcelable接口
 68         dest.writeInt(type);
 69         dest.writeString(title);
 70         dest.writeString(content);
 71         dest.writeInt(icon);
 72         dest.writeInt(movie_res);
 73     }
 74 
 75     public static void test(){
 76 
 77         int sz = -1,position = -1;
 78         //1,准备一个Parcel,其它数据放入其中
 79         Parcel parcel = Parcel.obtain();
 80         sz = parcel.dataSize();
 81         position = parcel.dataPosition();
 82 
 83         //2,准备要写入的对象，其中包含另一个实现了Parcelable的对象
 84         ContactBean cb = new ContactBean();
 85         cb.name = "name";
 86         cb.sectionCount = 3;
 87         cb.isSection = true;
 88         cb.icon = R.drawable.ebf;
 89 
 90         MsgBean mb1 = new MsgBean();
 91         mb1.type = 1;
 92         mb1.icon = R.drawable.ebf;
 93         mb1.content = "content";
 94         mb1.title = "title";
 95         mb1.contact = cb;
 96         mb1.movie_res = R.raw.movie;
 97 
 98         //3,写入
 99         mb1.writeToParcel(parcel,1);
100         sz = parcel.dataSize();
101         position = parcel.dataPosition();
102 
103         //4,读取
104         MsgBean mb2 = MsgBean.CREATOR.createFromParcel(parcel);
105 
106         MsgBean mb3 = parcel.readParcelable(MsgBean.class.getClassLoader());
107 
108         parcel.writeParcelable(mb1, 0);
109 
110         MsgBean mb4 = MsgBean.CREATOR.createFromParcel(parcel);
111         MsgBean mb5 = parcel.readParcelable(MsgBean.class.getClassLoader());
112 
113 
114         //5,开始序列
115         Intent intent = new Intent();
116         intent.putExtra("parcelable",mb1);
117         intent.putExtra("int",100);
118 
119         //6,开始反序列
120         //通常是在另一个地方得到上面的Intent
121         MsgBean mb6 = intent.getParcelableExtra("parcelable");
122         int data = intent.getIntExtra("int",-1);
123     }
124 }

 

posted @ 2016-07-14 15:50  f9q  阅读(375)  评论(0)  编辑  收藏  举报