Activity间要传递数据，很多时候简单的int和string满足不了需求，我们在面向对象中已经习惯了类和对象，
那么下面就说一下如何传递类对象。
Android中有两种办法来完成这件事。一个是Java的序列化（Serializable），另一个是Android的Parcelable序列化方法。
对于第一种办法实现很简单，只需要实现Serializable接口就好了。就像下面是一个person类：
package com.linc.meta;
import java.io.Serializable;
@SuppressWarnings("serial")
public class Person2 implements Serializable {
private String Name = null;
private String Gender = null;
private int HP = 0;
private String Summary = null;
private String Skill = null;
public Person2(String name,String gender,int HP,String summary,String skill)
{
this.Name = name;
this.Gender = gender;
this.Summary = summary;
this.HP = HP;
this.Skill = skill;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public String getGender() {
return Gender;
}
public void setGender(String gender) {
Gender = gender;
}
public int getHP() {
return HP;
}
public void setHP(int hP) {
HP = hP;
}
public String getSummary() {
return Summary;
}
public void setSummary(String summary) {
Summary = summary;
}
public String getSkill() {
return Skill;
}
public void setSkill(String skill) {
Skill = skill;
}
}
怎么样，很简单的把原来的person类实现Serializable接口就可以了。
对于第二种办法，实现起来还是稍微有点小磕绊。
这是Android新提供的序列化类，首先要看看Parcel类 ，它是一个数据的容器，只要你的类实现Parcelable接口，并完成几个步骤就可以放到Parcel中传递了。
有三个步骤要完成：
一、完成writeToParcel(Parcel dest, int flags)方法：该方法将类的数据写入外部提供的Parcel中
二、完成describeContents()：这是返回描述性的东西，返回值是整型，通常是0.如果知道marshalled，请看CONTENTS_FILE_DESCRIPTOR
三、Parcelable.Creator 接口
请看下面，还是person类，它实现了Parcelable接口。
package com.linc.meta;
import android.os.Parcel;
import android.os.Parcelable;
public class Person implements Parcelable {
private String Name = null;
private String Gender = null;
private int HP = 0;
private String Summary = null;
private String Skill = null;
public Person(String name,String gender,int HP,String summary,String skill)
{
this.Name = name;
this.Gender = gender;
this.Summary = summary;
this.HP = HP;
this.Skill = skill;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public String getGender() {
return Gender;
}
public void setGender(String gender) {
Gender = gender;
}
public int getHP() {
return HP;
}
public void setHP(int hP) {
HP = hP;
}
public String getSummary() {
return Summary;
}
public void setSummary(String summary) {
Summary = summary;
}
public String getSkill() {
return Skill;
}
public void setSkill(String skill) {
Skill = skill;
}
//Describe the kinds of special objects contained in this Parcelable's marshalled representation.
//CONTENTS_FILE_DESCRIPTOR
@Override
public int describeContents() {
// TODO Auto-generated method stub
return 0;
}
//该方法将类的数据写入外部提供的Parcel中
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(Name);
dest.writeString(Gender);
dest.writeString(Summary);
dest.writeInt(HP);
dest.writeString(Skill);
}
public static final Parcelable.Creator<Person> CREATOR = new Creator<Person>()
{
@Override
public Person createFromParcel(Parcel source) {
return new Person(source);
}
@Override
public Person[] newArray(int size) {
return new Person[size];
}
};
private Person(Parcel dest)
{
this.Name = dest.readString();
this.Gender = dest.readString();
this.Summary = dest.readString();
this.HP = dest.readInt();
this.Skill = dest.readString();
}
}
最后举一个例子，有两个Activity A和B，A中点击button后用Serializable传给B person，然后在B中点击button，把person用parcelable再传回来。
activity A
package com.linc;
import com.linc.meta.Person;
import com.linc.meta.Person2;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class ActivityA extends Activity {
private TextView txt ;
private Button btn;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txt = (TextView)findViewById(R.id.txt);
btn = (Button)findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
transferData();
}
});
Intent intent = getIntent();
Person person = (Person) intent.getParcelableExtra("person");
if(person != null)
txt.setText("person :\n " + person.getName() + " \n "
+ person.getGender() + " \n "
+ person.getSummary() + " \n "
+ person.getHP() + " \n "
+ person.getSkill());
}
private void transferData()
{
Person2 person = new Person2("张飞", "男", 4, "五虎上将之一。燕山人士，喜欢喝酒，生性豪放重情义。", "咆哮");
Intent intent = new Intent();
intent.setClass(this, ActivityB.class);
intent.putExtra("person2", person);
startActivity(intent);
}
}
ActivityB
package com.linc;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.linc.meta.Person;
import com.linc.meta.Person2;
public class ActivityB extends Activity {
private TextView txt ;
private Button btn;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txt = (TextView)findViewById(R.id.txt);
btn = (Button)findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
transferData();
}
});
Intent intent = getIntent();
if(intent != null)
{
Person2 person = (Person2) intent.getSerializableExtra("person2");
txt.setText("person : \n" + person.getName() + " \n "
+ person.getGender() + " \n "
+ person.getSummary() + " \n "
+ person.getHP() + " \n "
+ person.getSkill());
}
}
private void transferData()
{
Person person = new Person("黄盖", "男", 4, "东吴老将，配合周瑜使用苦肉计，骗过了将干，舍身无畏。", "苦肉");
Intent intent = new Intent();
intent.setClass(this, ActivityA.class);
intent.putExtra("person", person);
startActivity(intent);
}
}
也可以用parcelable来传递多个类对象。
就是把多个person放到list中，然后取时用intent.getParcelableArrayListExtra("person_list")取出。就okay了。
源码在这里。