Android Studio初学者实例：Activity之间数据传递--小猴子摘桃

此次学习的目的是学习Activity之间数据传递，包括了传递数据以及数据回传

主题是课堂上的案例小猴子摘桃：话不多说，看一下效果图：

后续代码讲解会在后续补充

 首先看一下第一个Activity的xml文件，也就是首页

我这里的文件名为activity_main48.xml，可以自行更改，用的文件并不多，activity两个

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity48">
<TextView
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="#008577"
    android:gravity="center"
    android:text="首页"
    android:textColor="@color/white"
    android:textSize="20sp"/>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/bg"
        android:gravity="center_vertical">
        <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/iv_monkey"
            android:src="@drawable/monkey"/>
        <Button
            android:layout_width="80dp"
            android:layout_height="30dp"
            android:id="@+id/btn_peach"
            android:layout_marginLeft="30dp"
            android:layout_marginTop="20dp"
            android:layout_toRightOf="@+id/iv_monkey"
            android:background="@drawable/btn_peach"
            android:text="去桃园"
            android:textColor="@color/black"/>
        <ImageView
            android:layout_width="45dp"
            android:layout_height="35dp"
            android:layout_centerHorizontal="true"
            android:id="@+id/iv_peach"
            android:layout_marginTop="80dp"
            android:src="@drawable/peach_pic"/>
 
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/tv_count"
            android:layout_marginTop="85dp"
            android:layout_toRightOf="@id/iv_peach"
            android:text="摘到0个"
            android:textColor="@color/black"
            android:textSize="16sp"/>
    </RelativeLayout>
</LinearLayout>

 第二个界面代码:

activity_main47.xml（可以自行更改）

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:theme="@style/Theme.AppCompat.NoActionBar"
    android:orientation="vertical"
    tools:context=".MainActivity47">
<TextView
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="#008577"
    android:text="桃园"
    android:textColor="@color/white"
    android:textSize="20sp"
    android:gravity="center"/>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/tree_bg">
        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerInParent="true"
            android:layout_marginTop="70dp"
            android:background="@drawable/tree">
            <Button
                android:layout_width="45dp"
                android:layout_height="35dp"
                android:layout_marginLeft="85dp"
                android:id="@+id/btn_one"
                android:layout_marginTop="25dp"
                android:background="@drawable/peach_pic"/>
            <Button
                android:layout_width="45dp"
                android:layout_height="35dp"
                android:id="@+id/btn_two"
                android:layout_below="@+id/btn_one"
                android:layout_marginLeft="50dp"
                android:layout_marginTop="5dp"
                android:background="@drawable/peach_pic"/>
            <Button
                android:layout_width="45dp"
                android:layout_height="35dp"
                android:id="@+id/btn_three"
                android:layout_below="@id/btn_one"
                android:layout_marginLeft="25dp"
                android:layout_marginTop="5dp"
                android:layout_toRightOf="@id/btn_two"
                android:background="@drawable/peach_pic"/>
            <Button
                android:layout_width="45dp"
                android:layout_height="35dp"
                android:id="@+id/btn_four"
                android:layout_below="@id/btn_two"
                android:layout_marginLeft="25dp"
                android:layout_marginTop="5dp"
                android:background="@drawable/peach_pic"/>
            <Button
                android:layout_width="45dp"
                android:layout_height="35dp"
                android:id="@+id/btn_five"
                android:layout_below="@id/btn_two"
                android:layout_marginLeft="25dp"
                android:layout_marginTop="5dp"
                android:layout_toRightOf="@id/btn_four"
                android:background="@drawable/peach_pic"/>
            <Button
                android:layout_width="45dp"
                android:layout_height="35dp"
                android:id="@+id/btn_six"
                android:layout_below="@id/btn_two"
                android:layout_marginLeft="25dp"
                android:layout_marginTop="5dp"
                android:layout_toRightOf="@id/btn_five"
                android:background="@drawable/peach_pic"/>
 
 
 
        </RelativeLayout>
        <Button
            android:layout_width="80dp"
            android:layout_height="30dp"
            android:layout_alignParentRight="true"
            android:layout_alignParentBottom="true"
            android:layout_margin="50dp"
            android:background="@drawable/btn_peach"
            android:text="退出桃园"
            android:textColor="@color/black"
            android:id="@+id/btn_exit"/>
    </RelativeLayout>
 
</LinearLayout>

 MainActivity48：对应第一个xml文件的逻辑代码（可以自行命名）

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
 
public class MainActivity48 extends AppCompatActivity {
private Button btn_peach;
private TextView tv_count;
private int totalCount=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main48);
        init();
    }
    public  void  init(){
        btn_peach=findViewById(R.id.btn_peach);
        tv_count=findViewById(R.id.tv_count);
        btn_peach.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent(MainActivity48.this,MainActivity47.class);
                startActivityForResult(intent,1);
            }
        });
    }
 
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable @org.jetbrains.annotations.Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode==1&&requestCode==1){
            int count=data.getIntExtra("count",0);
            totalCount=totalCount+count;
            tv_count.setText("摘到"+totalCount+"个");
        }
    }
}

 MainActivity47：

import androidx.appcompat.app.AppCompatActivity;
 
import android.content.Intent;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
 
public class MainActivity47 extends AppCompatActivity implements View.OnClickListener {
private Button btn_one,btn_two,btn_three,btn_four,btn_five,btn_six,btn_exit;
private int count=0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main47);
        init();
    }
    private  void init(){
        btn_one=findViewById(R.id.btn_one);
        btn_two=findViewById(R.id.btn_two);
        btn_three=findViewById(R.id.btn_three);
        btn_four=findViewById(R.id.btn_four);
        btn_five=findViewById(R.id.btn_five);
        btn_six=findViewById(R.id.btn_six);
        btn_exit=findViewById(R.id.btn_exit);
        btn_one.setOnClickListener(this);
        btn_two.setOnClickListener(this);
        btn_three.setOnClickListener(this);
        btn_four.setOnClickListener(this);
        btn_five.setOnClickListener(this);
        btn_six.setOnClickListener(this);
        btn_exit.setOnClickListener(this);
    }
 
    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btn_one:info(btn_one);break;
            case R.id.btn_two:info(btn_two);break;
            case R.id.btn_three:info(btn_three);break;
            case R.id.btn_four:info(btn_four);break;
            case R.id.btn_five:info(btn_five);break;
            case R.id.btn_six:info(btn_six);break;
            case R.id.btn_exit:returnData();break;
        }
    }
    private void  info(Button button){
        count++;
        button.setVisibility(View.INVISIBLE);
        Toast.makeText(MainActivity47.this,"摘到了"+count+"个桃子",Toast.LENGTH_SHORT).show();
    }
    private  void returnData(){
        Intent intent=new Intent();
        intent.putExtra("count",count);
        setResult(1,intent);
        MainActivity47.this.finish();
    }
 
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode==KeyEvent.KEYCODE_BACK&&event.getRepeatCount()==0){
            returnData();
        }
        return false;
    }
}