How to make onClick method to work? Not working for me

Question

I'm following this tutorial : https://codelabs.developers.google.com/codelabs/build-your-first-android-app/#6.

It is a tutorial for Android Studio beginners.

In the 'make the app interactive part' I have to add a onClick property to a method called countMe.

I did that but when I run the app, it crashes saying, "(nameofapp) keeps closing."

I've tried researching but nothing seems to solve the answer.

activity_main.xml file:

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

    <TextView
        android:id="@+id/textView2"
        android:layout_width="165dp"
        android:layout_height="65dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="120dp"
        android:layout_marginRight="120dp"
        android:text="     0"
        android:textSize="50sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.298" />

    <Button
        android:id="@+id/random_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="96dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:text="random"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

    <Button
        android:id="@+id/count_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="64dp"
        android:layout_marginLeft="64dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:onClick="countMe"
        android:text="count"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/random_button"
        app:layout_constraintHorizontal_bias="0.016"
        app:layout_constraintStart_toEndOf="@+id/toast_button"
        app:layout_constraintTop_toBottomOf="@+id/textView2"
        app:layout_constraintVertical_bias="0.613" />


    <Button
        android:id="@+id/toast_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="96dp"
        android:layout_marginBottom="8dp"
        android:onClick="toastMe"
        android:text="toast"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView2" />

main Activity java file:

    package com.example.myapptest;

    import androidx.appcompat.app.AppCompatActivity;

    import android.os.Bundle;
    import android.view.View;
    import android.widget.TextView;
    import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

    public void toastMe(View view){
        // Toast myToast = Toast.makeText(this, message, duration);
        Toast myToast = Toast.makeText(this, "Hello Toast!",
                Toast.LENGTH_SHORT);
        myToast.show();
    }

    public void countMe (View view) {
        // Get the text view.
        TextView showCountTextView = (TextView)
                findViewById(R.id.textView2);

        // Get the value of the text view.
        String countString = showCountTextView.getText().toString();

        // Convert value to a number and increment it.
        Integer count = Integer.parseInt(countString);
        count++;

        // Display the new value in the text view.
        showCountTextView.setText(count.toString());
    }

}

I don't think its a problem with the code. Anything helps. thank you.

"I don't think its a problem with the code" - why do you think so? Also include your logcat, because "when I run the app, it crashes" is not helpful — QBrute, Aug 17 '19 at 17:58
Possible duplicate of [Unfortunately MyApp has stopped. How can I solve this?](https://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this) — Zoe, Aug 17 '19 at 21:06

score 1 · Answer 1 · answered Aug 17 '19 at 18:19

The problem is that you have initially set the text of the TextView to:

android:text="     0"

which can't be parsed to an Integer.
Set it to:

android:text="0"

or in your code change this line:

String countString = showCountTextView.getText().toString();

to:

String countString = showCountTextView.getText().toString().trim();

How to make onClick method to work? Not working for me

1 Answers1