[移动开发]Android 页面跳转后返回

最近想做一个设置按钮，完事后返回。

先上大概效果：

实现过程：

1、在activity_main中添加一个设置按钮和一个文本显示：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    tools:context=".MainActivity">


    <TextView
        android:id="@+id/textView2"
        android:layout_width="293dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="700dp"
        android:layout_marginTop="205dp"
        android:text="接收返回值"
        android:textColor="@color/black"
        android:textSize="45sp" />

    <Button
        android:id="@+id/button"
        android:layout_width="161dp"
        android:layout_height="75dp"
        android:layout_marginStart="500dp"
        android:layout_marginTop="200dp"
        android:text="设置" />
</FrameLayout>

2、在layout中添加一个activity_setting.xml，添加一个返回按钮

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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">

    <Button
        android:id="@+id/button2"
        android:layout_width="161dp"
        android:layout_height="75dp"
        android:layout_marginStart="100dp"
        android:layout_marginTop="100dp"
        android:text="返回" />

</FrameLayout>

3、在AndroidManifest.xml中注册?.SettingActivity

4、添加SettingActivity类。

编辑MainActivity.java和SettingActivity.java

package com.example.jumptest;

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 MainActivity extends AppCompatActivity {
    final static int REQUEST=10;
    private Button btnSetting;
    private TextView tv;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnSetting=(Button) findViewById(R.id.button);
        tv = (TextView) findViewById(R.id.textView2);
        // 对按钮添加点击事件的监听
        btnSetting.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(MainActivity.this,SettingActivity.class);
                startActivityForResult(intent, REQUEST);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == REQUEST) {
            if (resultCode == RESULT_OK) {
                tv.setText("成功");
            }else if (resultCode == RESULT_CANCELED) {
                tv.setText("失败");
            } 

        }


    }

}

package com.example.jumptest;


import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;

public class SettingActivity extends AppCompatActivity {
    private Button btn1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_setting);
        btn1 = (Button) findViewById(R.id.button2);

        btn1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent data = new Intent();
                setResult(RESULT_OK, data);
                finish();
            }
        });
    }
}