Android Studio Changing TextView using a Button - android-studio

Question

I want to change the text in message when the button is clicked to "Hello World!".The idea would be that it would use a method inorder to change the text from a blank TextView into one that has writing on.
activity_main.xml
<?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/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="sendMessage"
android:text="Button"
tools:layout_editor_absoluteX="158dp"
tools:layout_editor_absoluteY="282dp" />
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.java
package com.example.clickmeapp;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import java.util.Set;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void sendMessage(View message){
message.text="Hello World!";
}
}
Any help in solving this issue would be amazing.

Answer 1

In my code, when you click the button, you will see the "Hello World!" text.
xml
<TextView
android:id="#+id/message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
Java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//add this code
//Button Click
findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//Set TextView
setMessage("Hello World!");
}
});
}
public void setMessage(String message){
findViewById(R.id.message).setText(message);
}