Android之Activity之间传递对象

Posted 2020-09-27 wzjhoutai

在非常多时候，我们须要在Activity之间传递对象，比方当你点击了某列表的item，须要传递给下一个Activity该对象，那我们须要该怎么做呢？

android支持两种传递对象的方式。一种是bundle.putSerializable方式，一种是bundle.putParcelable。

那么以下我们就用一个样例来实践Activity传递对象：

1.首先建立两个类，一个Teacher类表示老师，一个Student类表示学生。内容分别例如以下：

<span style="font-size:18px;">public class Teacher implements Serializable {

	private static final long serialVersionUID = -7060210544600464481L;

	private String name;
	private int age;
	private String addr;

	public Teacher(String name, int age, String addr) {
		super();
		this.name = name;
		this.age = age;
		this.addr = addr;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getAddr() {
		return addr;
	}

	public void setAddr(String addr) {
		this.addr = addr;
	}

	@Override
	public String toString() {
		String temp = "老师姓名：" + this.name + " 年龄：" + this.age + " 地址："
				+ this.addr;
		return temp;
	}

}</span>

<span style="font-size:18px;">import android.os.Parcel;
import android.os.Parcelable;

public class Student implements Parcelable {

	private String name;
	private int age;
	private String addr;

	public static final Parcelable.Creator<Student> CREATOR = new Creator<Student>() {

		@Override
		public Student[] newArray(int size) {
			return new Student[size];
		}

		@Override
		public Student createFromParcel(Parcel source) {
			Student stu = new Student();
			stu.name = source.readString();
			stu.age = source.readInt();
			stu.addr = source.readString();
			return stu;
		}
	};

	@Override
	public int describeContents() {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public void writeToParcel(Parcel dest, int flags) {
		dest.writeString(name);
		dest.writeInt(age);
		dest.writeString(addr);
	}
	
	public Student(){
		
	}
	
	public Student(String name, int age, String addr) {
		super();
		this.name = name;
		this.age = age;
		this.addr = addr;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getAddr() {
		return addr;
	}

	public void setAddr(String addr) {
		this.addr = addr;
	}
	
	@Override
	public String toString() {
		String temp = "学生姓名：" + this.name + " 年龄：" + this.age + " 地址："
				+ this.addr;
		return temp;
	}
	
}</span>

当中Teacher类实现了Serializable接口，Student类实现了Parcelable接口。

2.创建两个Activity，第一个Activity叫做FirstActivity。它里面有两个对象：一个Teacher对象，一个Student对象，我们如今须要将这两个对象传递给第二个Activity。即SecondActivity。

首先我们看一下FirstActivity的布局：

FirstActivity的内容例如以下：

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;

public class FirstActivity extends Activity implements OnClickListener{
	
	public static final String TEACHER_KEY = "key_teacher";
	public static final String STUDENT_KEY = "key_student";
	
	private Teacher teacher = new Teacher("刘备", 36, "荆州");
	private Student student = new Student("张飞", 32, "新野");
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_first);
		
		findViewById(R.id.button1).setOnClickListener(this);
	}

	@Override
	public void onClick(View v) {
		switch (v.getId()) {
		case R.id.button1:
			Bundle bundle = new Bundle();
			bundle.putSerializable(TEACHER_KEY, teacher);
			bundle.putParcelable(STUDENT_KEY, student);
			Intent intent = new Intent(FirstActivity.this,SecondActivity.class);
			intent.putExtras(bundle);
			startActivity(intent);
			break;

		default:
			break;
		}
		
	}

}

然后我们再看一下SecondActivity的布局：

里面就仅仅有一个TextView。

然后我们看一下SecondActivity的内容，它主要是将传递过来的对象显示到TextView其中：

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.widget.TextView;

public class SecondActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_second);
		
		Intent intent = this.getIntent();
		Bundle bundle = intent.getExtras();
		Teacher t = (Teacher) bundle.getSerializable(FirstActivity.TEACHER_KEY);
		Student s = bundle.getParcelable(FirstActivity.STUDENT_KEY);
		
		String text = t.toString() + "\n" + s.toString();
		
		((TextView)findViewById(R.id.text_view)).setText(text);
	}


}

当我们点击了FirstActivity的界面上的"開始传递对象"button后，跳转到SecondActivity，界面例如以下：

非常显然，这两种方式都能够成功的在Activity之间传递对象。

希望以上内容对各位读者可以带来帮助！