Its a very basic example to implement onClickListener for Button: - Button A, define onClickListener as anonymous class. - Button B1 and B2: define onClickListener class. - Button C1 and C2: assign callback function in XML. activity_main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayout android_id="@+id/background" android_layout_width="match_parent" android_layout_height="match_parent" android_padding="16dp" android_orientation="vertical" android_onClick="onBackgroundClickedCallback" tools_context="com.blogspot.android_er.androidclicklistener.MainActivity"> <TextView android_layout_width="wrap_content" android_layout_height="wrap_content" android_layout_gravity="center_horizontal" android_autoLink="web" android_text="http://android-er.blogspot.com/" android_textStyle="bold" /> <Button android_...