choiboi

// Overriden onClick method. This method will invoke for buttons that has been set with the on click listener
// with this class.
@Override
public void onClick(View v) {
    Toast.makeText(this, "Button listener implemented through this class pressed!", Toast.LENGTH_LONG).show();
}

choiboi

<!-- Must have onClick attribute with the method name as the value. -->
<Button
    android:id="@+id/button_xml_attribute"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/button_xml_attribute_text"
    android:onClick="onButtonPressed" />

choiboi

// This method will invoke with the button that has the xml attribute onClick set with this method name.
public void onButtonPressed(View v) {
    Toast.makeText(this, "Button listener implemented xml onClick attribute!", Toast.LENGTH_LONG).show();
}

choiboi

// Button listener implemented by not implmenting this class with
// OnClickListener. When button is pressed, it will invoke the onClick method
// inside the OnClickListener object created when the listener has been set.
Button implementListenerButton = (Button) findViewById(R.id.button_object_onclicklistener);
implementListenerButton.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View arg0) {
        Toast.makeText(ButtonMainActivity.this, "Button listener created while setting the button listener pressed!", Toast.LENGTH_LONG).show();
    }
});