Android Studio 2.2.3 - Could not find method onButtonClick - Two methods appear in Design

Question

The error:

java.lang.IllegalStateException: Could not find method onButtonClick (MainActivity)(View) in a parent or ancestor Context for android:onClick attribute defined on view class android.support.v7.widget.AppCompatButton with id 'bSetTime'

I have only made one method in java.

When I select the second onButtonClick in Design the app works, but when I restart the app it crashes again and it has the first method selected. I can then select the second option again and restart the app. to repeat this process.

In other answers it was suggested to just use: button.setOnClickListener. It works, but I'd like to learn from this.

The java File:

package com.example.halfacht.pickers;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.TimePicker;

public class MainActivity extends AppCompatActivity {

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

        /* TIME PICKER */
        TimePicker tp = (TimePicker) findViewById(R.id.timePicker);
    }

    // Button
    public void onButtonClick(View e) {
        // TextView tvSetTime = (TextView) findViewById(R.id.textView);
        // TimePicker tp = (TimePicker) findViewById(R.id.timePicker);
        // tvSetTime.setText(tp.getCurrentHour().toString() + ":" + tp.getCurrentMinute().toString());
    }

}

My XML File:

    <TimePicker
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:id="@+id/timePicker"
        android:timePickerMode="spinner" />

    <TextView
        android:text="TextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/textView"
        android:layout_alignBaseline="@+id/bSetTime"
        android:layout_alignBottom="@+id/bSetTime"
        android:layout_toRightOf="@+id/bSetTime"
        android:layout_toEndOf="@+id/bSetTime"
        android:layout_marginLeft="54dp"
        android:layout_marginStart="54dp" />

    <Button
        android:text="Set Time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="38dp"
        android:id="@+id/bSetTime"
        android:layout_below="@+id/timePicker"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:onClick="onButtonClick (MainActivity)" />
    </RelativeLayout>

Two onClicks Appear in Design

Answer 1

Last line in your XML. Change this:

android:onClick="onButtonClick (MainActivity)"

to this:

android:onClick="onButtonClick"