XML : Change backgroun on click using xml file

I'm trying to change background of ImageView when i click on it , i learned that it could be done by creating XML file and make a selector so i did that but when i execute i see the background has already changed that's my codes :

change.XML file in drawable folder :

  <?xml version="1.0" encoding="utf-8"?>  <selector xmlns:android="http://schemas.android.com/apk/res/android" >      <item android:state_pressed="true">          <color android:color="#00FF00"/>      </item>  </selector>  

content_main.xml in Layout folder :

  <?xml version="1.0" encoding="utf-8"?>  <RelativeLayout 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"      android:paddingBottom="@dimen/activity_vertical_margin"      android:paddingLeft="@dimen/activity_horizontal_margin"      android:paddingRight="@dimen/activity_horizontal_margin"      android:paddingTop="@dimen/activity_vertical_margin"      app:layout_behavior="@string/appbar_scrolling_view_behavior"      tools:context="com.example.othma.test2.MainActivity"      tools:showIn="@layout/activity_main">          <ImageView          android:layout_width="200dp"          android:layout_height="200dp"          android:id="@+id/imageView"          android:src="@drawable/str"          android:maxWidth="@dimen/abc_button_padding_horizontal_material"          android:contentDescription="@string/imgstart"          android:layout_centerHorizontal="true"          android:layout_marginTop="82dp"          android:background="@drawable/change"          />  </RelativeLayout>  

Java Code :

  public class MainActivity extends AppCompatActivity {  @Override  protected void onCreate(Bundle savedInstanceState) {      //imgV = (ImageView) findViewById(R.id.imageView);      super.onCreate(savedInstanceState);      setContentView(R.layout.activity_main);  }    

}