Activity页面之间的数据传递

一.


1.在Activity之间传递数据

    <1>传递基本数据类型

        基本数据类型：

        整：byte short int long

        浮点：float double

        布尔：boolean

        字符：char

        引用：

        String

    <2>传递数据包Bundle  (集装箱)

    <3>传递对象(对象集合)

    <4>返回数据

二.咱们直接来看一段代码

(1)首先是xml页面1

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="com.example.my_android_02_01.MainActivity">

<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入用户名"
android:id="@+id/main_uname"
/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="写心情"
android:onClick="writeThink"
/>

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/main_showThink"
/>
</LinearLayout>


(2)xml页面2
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/think_showName"
/>

<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:lines="5"
android:hint="请写心情"
android:gravity="top"
android:id="@+id/think_content"
/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="确定"
android:onClick="ok"
/>

</LinearLayout>

(3)再是java类1

package com.example.my_android_02_01;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import com.example.entity.Person;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

private EditText editText;
private TextView textView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = (EditText) findViewById(R.id.main_uname);
textView = (TextView) findViewById(R.id.main_showThink);
Log.i("test","onCreate");

}
public  void writeThink(View view){
//        String uname=editText.getText().toString();
Intent intent=new Intent(this,ThinkActivity.class);
//传递对象
Person person1=new Person(1,"hy",19);
Person person2=new Person(2,"tiny",19);
Person person3=new Person(3,"x",19);

ArrayList<Person> persons=new ArrayList<>();
persons.add(person1);
persons.add(person2);
persons.add(person3);
//传递对象集合
intent.putParcelableArrayListExtra("persons",persons);

//带有目的的跳转
//startActivityForResult(intent,0x201);
startActivityForResult(intent,0x201);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Log.i("test","onActivityResult");
String content=data.getStringExtra("content");
textView.setText(content);
}
}

(4)java类4

package com.example.my_android_02_01;

import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

import com.example.entity.Person;

import java.util.List;

/**
* Created by Administrator on 2017/6/16.
*/
public class ThinkActivity extends AppCompatActivity {

private TextView textView;
private EditText editText;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_think);
textView = (TextView) findViewById(R.id.think_showName);
editText = (EditText) findViewById(R.id.think_content);

//接受对象集合
List<Person>persons=getIntent().getParcelableArrayListExtra("persons");
textView.setTextSize(30);
for (Person person : persons) {
textView.setText(textView.getText()+"\n"+person.toString());
}
}
public void ok(View v){
String content=editText.getText().toString();
Intent i=new Intent();
i.putExtra("content",content);
//设置结果
setResult(0x100,i);
//自杀(干掉自己，干掉当前的Activity)
finish();

}

}

还需写一个person类

package com.example.entity;

import android.os.Parcel;
import android.os.Parcelable;

/**
* Created by Administrator on 2017/6/16.
*/
public class Person implements Parcelable {

private  int pid;
private  String pname;
private  int page;

public Person() {
}

public Person(int pid, String pname, int page) {
this.pid = pid;
this.pname = pname;
this.page = page;
}

protected Person(Parcel in) {
pid=in.readInt();
pname=in.readString();
page=in.readInt();

}

public static final Creator<Person> CREATOR = new Creator<Person>() {
@Override
public Person createFromParcel(Parcel in) {
return new Person(in);
}

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

public int getPid() {
return pid;
}

public void setPid(int pid) {
this.pid = pid;
}

public String getPname() {
return pname;
}

public void setPname(String pname) {
this.pname = pname;
}

public int getPage() {
return page;
}

public void setPage(int page) {
this.page = page;
}

@Override
public String toString() {
return "Person{" +
"pid=" + pid +
", pname='" + pname + '\'' +
", page=" + page +
'}';
}

@Override
public int describeContents() {
return 0;
}

@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(pid);
dest.writeString(pname);
dest.writeInt(page);
}
}

就结束了

三.效果图