按下按钮后android studio中的活动不会切换

Question

I've already tried searching the Google on how to switch activities in android studio, even in the official documentation with tutorial. I did it exactly like it was said but I am still unable to get redirected to another activity after clicking a button.

I've entered an onClick name of the method to the button

it looks like this: https://i.imgur.com/pmsztaL.png (can't post images yet)

and this is my MainActivity.class file with said method

public class MainActivity extends AppCompatActivity {

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

    public void handleButtonAddNew(View view) {
        MainActivity.this.startActivity(new Intent(MainActivity.this, AddItemActivity.class));
    }
}

After pressing the button in a phone, the button does nothing.

This is my AddItemActivity.class

public class AddItemActivity extends AppCompatActivity {

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


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

How come the button doesn't work, what did I do wrong?

EDITS

EDIT: Successfully ran emulator and the buttons did in fact work, the problem lies within my phone, the buttons there don't want to work. Where could be the issue now?

EDIT: XML Layout of MainActivity.class

<?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"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/buttonAddNew"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="188dp"
        android:layout_marginRight="188dp"
        android:layout_marginBottom="264dp"
        android:text="@string/buttonAdd"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <ScrollView
        android:id="@+id/scrollView2"
        android:layout_width="395dp"
        android:layout_height="715dp"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

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

</android.support.constraint.ConstraintLayout>

EDIT: The problem was with scroll view blocking the clickable button so on my phone the button didn't register any clicks, after removing the scrollview the button works normally.

Answer 1

I'm afraid that this button doesn't get any listeners attached.

The programatic approach

From the Official Android Documentation

I'd suggest you use this in your onCreate callback:

Button button = (Button) findViewById(R.id.your_btn_id);
button.setOnClickListener((view) -> { theMethodYouWantToCallHere(view); });

XML approach

Please double check the following using this approach

1. Your activity is registered in the AndroidManifest.xml
2. You're including the android namespace to the XML file in the parent container of the layout file. IE: xmlns:android="http://schemas.android.com/apk/res/android"
3. Make sure you're setting the content view for the activity with setContentView(R.layout.your_layout_file);
4. Once 2 is satisfied make sure you're using the android namespace. IE: android:onClick="yourMethod"
5. As you're currently doing: Make sure the onClick callbacked method has the View view parameter; no more, no less
6. Make sure the onClick function is public in the activity.
7. And that no other clickable views are covering the view you're registering the onClick listener for :) Including the namespace: xmlns:android="http://schemas.android.com/apk/res/android"

XML file

<FrameLayout
            xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:app="http://schemas.android.com/apk/res-auto"
            android:fitsSystemWindows="true"
            android:layout_width="match_parent"
            android:layout_height="match_parent">
        <Button android:text="Click me!"  android:onClick="clicked" android:layout_height="wrap_content" android:layout_width="wrap_content"/>

</FrameLayout>

The activity

public class MainActivity extends AppCompatActivity {

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

    public void clicked(View view){
        Toast.makeText(this, "Hey! Im clicked!",Toast.LENGTH_SHORT).show();
    }

}