XML : Resize View when Keyboard appears

My Problem is that when i click on an Edit Text and the Keyboard appears that the Keyboard is over my Edit Text and the Button and only if i press any button on the keyboard the View updates and the Edit Text and the Button are over the Keyboard. And when i press Back the Keyboard close but the View dont update und i have where the Keyboard was a blank space. The Layout called from class is:

  <android.support.v4.widget.DrawerLayout 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:id="@+id/drawer_layout"      android:layout_width="match_parent"      android:layout_height="match_parent"      android:fitsSystemWindows="true"      tools:openDrawer="start">        <include layout="@layout/app_bar_chat"          android:layout_width="match_parent"          android:layout_height="match_parent" />        <android.support.design.widget.NavigationView          android:id="@+id/nav_view"          android:layout_width="wrap_content"          android:layout_height="match_parent"          android:layout_gravity="start"          android:fitsSystemWindows="true"          app:headerLayout="@layout/nav_header_main"          app:menu="@menu/activity_main_drawer" />  </android.support.v4.widget.DrawerLayout>    

The app_bar_chat xml:

  <android.support.v4.widget.DrawerLayout 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:id="@+id/drawer_layout"      android:layout_width="match_parent"      android:layout_height="match_parent"      android:fitsSystemWindows="true"      tools:openDrawer="start">        <include layout="@layout/app_bar_chat"          android:layout_width="match_parent"          android:layout_height="match_parent" />        <android.support.design.widget.NavigationView          android:id="@+id/nav_view"          android:layout_width="wrap_content"          android:layout_height="match_parent"          android:layout_gravity="start"          android:fitsSystemWindows="true"          app:headerLayout="@layout/nav_header_main"          app:menu="@menu/activity_main_drawer" />  </android.support.v4.widget.DrawerLayout>    

And the content_chat layout:

  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"      xmlns:tools="http://schemas.android.com/tools"      xmlns:app="http://schemas.android.com/apk/res-auto"      android:layout_width="match_parent"      android:layout_height="match_parent"      android:background="@drawable/chatbackgroundcolor"      app:layout_behavior="@string/appbar_scrolling_view_behavior"      android:fitsSystemWindows="true"      tools:context=".Chat_activity"      tools:showIn="@layout/app_bar_chat"      android:orientation="horizontal">          <Button              android:layout_width="wrap_content"              android:layout_height="50dp"              android:text="  Send  "              android:id="@+id/btnsend"              android:layout_alignParentBottom="true"              android:layout_alignParentRight="true"              android:layout_alignParentEnd="true"/>            <EditText              android:layout_width="wrap_content"              android:layout_height="50dp"              android:id="@+id/texttosend"              android:layout_alignParentBottom="true"              android:layout_alignParentLeft="true"              android:layout_alignParentStart="true"              android:layout_toLeftOf="@+id/btnsend"              android:layout_toStartOf="@+id/btnsend"/>            <ListView              android:layout_width="wrap_content"              android:layout_height="wrap_content"              android:id="@+id/chatlistView"              android:layout_alignParentTop="true"              android:layout_alignParentLeft="true"              android:layout_alignParentStart="true"              android:layout_above="@+id/btnsend"              android:transcriptMode="alwaysScroll"              android:stackFromBottom="true"/>  </RelativeLayout>    

Im using a Drawer Layout and when i delete the row

  app:layout_behavior="@string/appbar_scrolling_view_behavior"    

in content_chat the view updates perfect but then the appbar is missing.