activity_main.xml

<?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"
    tools:context=".MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="主页面"
        android:onClick="mainClick"
        />
</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {
   

    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.v("chendandan","MainActivity onCreate()方法");
    }
    public void mainClick(View view){
   
        Log.v("chendandan","mainClick 会调用startActivityForResult");
        Intent intent=new Intent(this, ChildActivity.class);
        startActivityForResult(intent,1);

    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
   
        super.onActivityResult(requestCode, requestCode, data);
        if(requestCode==1){
   
            if(resultCode==1){
   
                String string=data.getStringExtra("Chen");
                Log.v("chendandan","获取的数据"+string);
            }
        }
    }

    @Override
    protected void onStart(){
   
        super.onStart();
        Log.v("chendandan","MainActivity onStart()方法");
    }

    @Override
    protected void onResume(){
   
        super.onResume();
        Log.v("chendandan","MainActivity onResume()方法");
    }

    @Override
    protected void onRestart(){
   
        super.onRestart();
        Log.v("chendandan","MainActivity onRestart()方法");
    }

    @Override
    protected void onStop(){
   
        super.onStop();
        Log.v("chendandan","MainActivity onStop()方法");
    }

    @Override
    protected void onPause(){
   
        super.onPause();
        Log.v("chendandan","MainActivity onPause()方法");
    }

    @Override
    protected void onDestroy(){
   
        super.onDestroy();
        Log.v("chendandan","MainActivity onDestroy()方法");
    }

}

activity_child.xml

<?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"
    tools:context=".ChildActivity">
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="子页面"
        android:onClick="childClick"
        />
</LinearLayout>

ChildActivity.java

public class ChildActivity extends Activity {
   
    @Override
    protected void onCreate(Bundle savedInstanceState) {
   
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_child);
        Log.v("chendandan","ChildActivity onCreate()方法");
    }
    public void childClick(View view){
   
        Log.v("chendandan","childClick 会调用finish();");
        Intent intent=new Intent(this, MainActivity.class);
        intent.putExtra("chen","子页面提交给主页面的数据");
        setResult(1,intent);
        finish();
        //startActivityForResult(intent,1);
    }


    @Override
    protected void onStart(){
   
        super.onStart();
        Log.v("chendandan","ChildActivity onStart()方法");
    }

    @Override
    protected void onResume(){
   
        super.onResume();
        Log.v("chendandan","ChildActivity onResume()方法");
    }

    @Override
    protected void onRestart(){
   
        super.onRestart();
        Log.v("chendandan","ChildActivity onRestart()方法");
    }

    @Override
    protected void onStop(){
   
        super.onStop();
        Log.v("chendandan","ChildActivity onStop()方法");
    }

    @Override
    protected void onPause(){
   
        super.onPause();
        Log.v("chendandan","ChildActivity onPause()方法");
    }

    @Override
    protected void onDestroy(){
   
        super.onDestroy();
        Log.v("chendandan","ChildActivity onDestroy()方法");
    }

}

运行结果: