[Android] Parcelable接口实现序列化

github连接：https://github.com/lixiang0/DemoLibs
在实际的使用中，我们经常需要在不同的进程中传递对象实例，但是却不能直接的传递对象，因而需要通过对象的序列化和反序列化来实现对对象的传递。序列化之后标志着我们可以直接传递对象了。

下面我们讲实现通过一个例子来利用Parcelable接口实现对象的序列化。通过在MainActivity中按钮的点击将一个User对象传递到MainActivity2并显示出来。

1.构造User类，并实现Parcelable接口

package string.pub.serial.entity;import android.os.Parcel;import android.os.Parcelable;public class User implements Parcelable{    String name="ruben";    int age=26;    String sex="man";    String addr="shenzhen";    String describe="a coder";    public User() {        // TODO Auto-generated constructor stub    }    public User(Parcel paramParcel) {        // TODO Auto-generated constructor stub        name=paramParcel.readString();        age=paramParcel.readInt();        sex=paramParcel.readString();        addr=paramParcel.readString();        describe=paramParcel.readString();    }    @Override    public String toString() {        return "User [name=" + name + ", age=" + age + ", sex=" + sex + ", addr=" + addr + ", describe=" + describe                + "]";    }    @Override    public int describeContents() {        // TODO Auto-generated method stub        return 0;    }    @Override    public void writeToParcel(Parcel paramParcel, int paramInt) {        // TODO Auto-generated method stub        paramParcel.writeString(name);        paramParcel.writeInt(age);        paramParcel.writeString(sex);        paramParcel.writeString(addr);        paramParcel.writeString(describe);    }    public static final Parcelable.Creator<User> CREATOR=new Creator<User>() {        @Override        public User[] newArray(int paramInt) {            // TODO Auto-generated method stub            return new User[paramInt];        }        @Override        public User createFromParcel(Parcel paramParcel) {            // TODO Auto-generated method stub            return new User(paramParcel);        }    };}

2.实现MainActivity:

package string.pub.serial;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.LinearLayout;import string.pub.serial.entity.User;public class MainActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        LinearLayout ll=new LinearLayout(this);        ll.setOrientation(LinearLayout.VERTICAL);        StringBuilder sb=new StringBuilder();        Button btn_click=new Button(this);        btn_click.setText("click to MainActivity2");        btn_click.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View paramView) {                // TODO Auto-generated method stub                Intent intent=new Intent();                intent.setClass(MainActivity.this, MainActivity2.class);                intent.putExtra("value", new User());                startActivity(intent);            }        });        ll.addView(btn_click);        setContentView(ll);    }}

3.实现MainActivity2:

package string.pub.serial;import android.app.Activity;import android.os.Bundle;import android.widget.LinearLayout;import android.widget.TextView;import string.pub.serial.entity.User;public class MainActivity2 extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {    // TODO Auto-generated method stub    super.onCreate(savedInstanceState);    LinearLayout ll=new LinearLayout(this);    ll.setOrientation(LinearLayout.VERTICAL);    TextView tv_content=new TextView(this);    User user=(User)getIntent().getParcelableExtra("value");    tv_content.setText(user.toString());    ll.addView(tv_content);    setContentView(ll);}}

4.注册清单文件：

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="string.pub.serial"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="14"        android:targetSdkVersion="21" />    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"></uses-permission>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@android:style/Theme.Holo.Light" >        <activity            android:name=".MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>                <activity            android:name=".MainActivity2"            android:label="@string/app_name" >            <intent-filter>            </intent-filter>        </activity>    </application></manifest>

5.实现效果：

总结：Parcelable接口是Android中的序列化与反序列化的实现方案，它可以实现在不同进程中进行对象的传输和持久化。