Android Studio: On button click go to previous activity (not the back button)

Question

I have to create two activity pages. In the first the user enters their name, which is passed to the second activity. That is all working, but when the second button is pressed "button_do" the app needs to exit, when the first "button_dont" it needs go to the previous activity to re enter the name. Also as another point I need to have the result of the editText go into a sharedPreferance as long as it is not already there... having problems with both aspects. Also the instructions say that the value of the button pressed needs to be 0 or 1.

<?xml version="1.0" encoding="utf-8"?>
<GridLayout 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"
    android:layout_row="4"
    android:layout_column="3"
    android:layout_weight="1"
    android:layout_gravity="fill"
    >

    <TextView
        android:id="@+id/textView"
        android:layout_width="256dp"
        android:layout_height="66dp"
        android:layout_row="0"
        android:layout_column="0"
        android:text="@string/enterName"
        android:textSize="30sp" />

    <EditText
        android:id="@+id/editText"
        android:layout_width="441dp"
        android:layout_height="wrap_content"
        android:layout_row="1"
        android:layout_column="0"
        android:layout_columnSpan="2"
        android:textSize="40sp"/>


    <Button
        android:id="@+id/next"
        android:layout_width="127dp"
        android:layout_height="64dp"
        android:layout_row="2"
        android:layout_column="0"
        android:text="@string/next" />
</GridLayout>

<?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=".NameActivity"
    android:orientation="vertical">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:id="@+id/welcome"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/welcome"
            android:textSize="30sp" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="416dp"
        android:layout_height="87dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/button_dont"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/dont_call"
            android:layout_margin="5sp"/>

        <Button
            android:id="@+id/button_do"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/thank_you"
            android:layout_margin="5sp"/>
    </LinearLayout>

</LinearLayout>

package com.example.androidlabs;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {

    Button next;
    EditText editText;
    public static final int REQ_CODE=1;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button next = findViewById(R.id.next);
        EditText editText = findViewById(R.id.editText);

        next.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent i = new Intent(getApplicationContext(),NameActivity.class);
                String name = editText.getText().toString();
                i.putExtra("Value",name);
                startActivityForResult(i,REQ_CODE);

            }
        });

    }

    @Override
    protected void onPause() {
        Object fileName;
        SharedPreferences prefs = getSharedPreferences("name.txt", Context.MODE_PRIVATE);
        super.onPause();
    }

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

        if(REQ_CODE==1){
            if(resultCode == REQ_CODE){
                int result = data.getIntExtra("result",0);
                if(result==0){
                    editText.setText("");
                } if(result==1){
                    finish();
                }
            }
        }
    }
}

package com.example.androidlabs;

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 NameActivity extends AppCompatActivity {

    public static final int REQ_CODE=1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_name);

        TextView welcome = findViewById(R.id.welcome);

        Intent i = getIntent();
        String name = i.getStringExtra("Value");
        welcome.setText("Welcome "+ name +"!");

        Button button_dont = findViewById(R.id.button_dont);
        Button button_do = findViewById(R.id.button_do);

        button_dont.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               int result=0;

                Intent resultIntent = new Intent();
                resultIntent.putExtra("result",result);

                setResult(REQ_CODE, resultIntent);
                finishActivity(REQ_CODE);


            }
        });
        button_do.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               int result=1;

                Intent resultIntent = new Intent();
                resultIntent.putExtra("result",result);
                setResult(REQ_CODE, resultIntent);
                finish();



            }
        });



    }
}

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. — Community, May 28 '22 at 03:15

Senti · Answer 1 · 2022-05-26T22:02:34.563

I wouldn't use an onClickListener() for the button_dont. but instead use something like this

    public void onButtonDo_Clicked(View caller){
    Intent intent = new Intent(this, MainActivity.class);
    startActivity(intent);
}

Make sure you set the OnClick of the button you use in the XML file to this method. In this way whenever you press the button, you go back to the previous Activity. it should look like this:

        <Button
        android:id="@+id/button_do"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onButtonDo_Clicked"
        android:text="@string/thank_you"
        android:layout_margin="5sp"/>

For the button_do I don't know why you would want the program to shut off. Its better to dont implement this and just use the android interface for this.

For the second problem, you can use prefs.contains(name) to check if an entry for that key exits already.

Android Studio: On button click go to previous activity (not the back button)

1 Answers1