无法将数据从第二个活动传递到主活动

Question

我在 Activity2 和 ActivityMain 之间传递数据时遇到问题。我有一个带有“添加人员”按钮的 ActivityMain。当我按下此按钮时，我会转到 Activity2，然后我填写字段名称并按下按钮“添加”，但无法在我的 ActivityMain 上添加名称。

ActivityMain.xml

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

<android.support.constraint.ConstraintLayout 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"

android:padding="5dp"

tools:context=".MainActivity">

<LinearLayout

 android:layout_width="match_parent"

 android:layout_height="match_parent"

 android:orientation="vertical">

<Button

    android:layout_width="match_parent"

    android:layout_height="wrap_content"

    android:text="Add Person"

    android:onClick="addPerson"

   />

</LinearLayout>

</android.support.constraint.ConstraintLayout>

ActivityMain.java

package com.example.test.zadanie01;

import android.content.Intent;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View; 

import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

@Override

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

}

protected void onActivityResult(int requestCode, int resultCode, Intent data){

        Intent intent = getIntent();

        String message = intent.getStringExtra(PersonActivity.EXTRA_MESSAGE);

        TextView textView = new TextView(this);

        textView.setTextSize(40);

        textView.setText(message);

        setContentView(textView);

}

public void addPerson(View view){

    Intent intent = new Intent(this, PersonActivity.class);

    startActivityForResult(intent, 1);

}

}

Answer 1

尝试更换String&nbsp;message&nbsp;=&nbsp;intent.getStringExtra(PersonActivity.EXTRA_MESSAGE);和String&nbsp;message&nbsp;=&nbsp;data.getStringExtra(PersonActivity.EXTRA_MESSAGE);