修复 android studio 制作的应用程序不断停止

Question

I'm new in the android development field when I try to transfer data between activities can't get my message and app got stopping show me app keep stopping

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;


import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;


public class MainActivity extends AppCompatActivity {

    Intent outIntent;
    EditText edtPhone;
    EditText edtMessage;
    Button btnNext;
    String tempText="";

   public static final String PHONE = "PHONE";
   public static final  String MESSAGE = "MESSAGE";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnNext = (Button) findViewById(R.id.btnNext);
        btnNext.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View V) {
                outIntent = new Intent(MainActivity.this, ActivityTwo.class);
                edtPhone = (EditText) findViewById(R.id.edtPhone);
                edtMessage = (EditText) findViewById(R.id.edtMessage);
                tempText = edtPhone.getText().toString();
                outIntent.putExtra(PHONE,tempText);
                tempText = edtMessage.getText().toString();
                outIntent.putExtra(MESSAGE,tempText);

                startActivity(outIntent);
            }

    });
}
    public void closeMethod(View view) {
        finish();
    }
}

ActivityTwo.java

package com.example.fir;

import android.content.Intent;
import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import android.widget.TextView;

public class ActivityTwo extends AppCompatActivity {

        Intent incomingIntent;
        TextView txtPhone;
        TextView txtMessage;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_two);
        incomingIntent = getIntent();
        txtPhone = (TextView) findViewById(R.id.txtPhone);
        txtMessage = (TextView) findViewById(R.id.txtMessage);
        txtPhone.setText(incomingIntent.getStringExtra(MainActivity.PHONE));
        txtMessage.setText(incomingIntent.getStringExtra(MainActivity.MESSAGE));

    }
}

Activitymain.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="32dp"
        android:text="Phone" />

    <EditText
        android:id="@+id/editTextPhone"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginStart="0dp"
        android:layout_marginTop="60dp"
        android:ems="10"
        android:hint="Phone"
        android:inputType="phone"
        android:minHeight="48dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="124dp"
        android:text="Message" />

    <EditText
        android:id="@+id/editTextTextPersonName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_centerHorizontal="true"
        android:layout_marginStart="0dp"
        android:layout_marginTop="156dp"
        android:layout_marginEnd="3dp"
        android:ems="10"
        android:hint="Message"
        android:inputType=""
        android:minHeight="48dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="224dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btnNext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Next" />

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="closeMethod"
            android:text="CLose" />
    </LinearLayout>
</RelativeLayout>

Activitytwo.xml
////

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="32dp"
        android:text="Phone" />

    <EditText
        android:id="@+id/editTextPhone"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginStart="0dp"
        android:layout_marginTop="60dp"
        android:ems="10"
        android:hint="Phone"
        android:inputType="phone"
        android:minHeight="48dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="124dp"
        android:text="Message" />

    <EditText
        android:id="@+id/editTextTextPersonName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true"
        android:layout_centerHorizontal="true"
        android:layout_marginStart="0dp"
        android:layout_marginTop="156dp"
        android:layout_marginEnd="3dp"
        android:ems="10"
        android:hint="Message"
        android:inputType=""
        android:minHeight="48dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="224dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btnNext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Next" />

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:onClick="closeMethod"
            android:text="CLose" />
    </LinearLayout>
</RelativeLayout>

my problem is when I don't put any value into the firstEditText or secondEditText or both of them and click on any button the app crashes and a pop up shows "myapp keeps stopping". i cannot get the text..

Answer 1

you have defined your Edit texts in the first activity with id's named

edtPhone
edtMessage

but there was no edtPhone or edtMessage in your xml. this issue also repeats in your second activity you have defined txtPhone and txtMessage but again there are no such ids in your second activity XML. keep in mind that these might not be the whole problem as you didn't post any log for the errors. but if there were anything else, ask and we'll help you