collapsing bar

<?xml version="1.0" encoding="utf-8"?><android.support.design.widget.CoordinatorLayout    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"    tools:context="com.blogspot.programer27android.collapsing.MainActivity">
    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"        android:layout_height="300dp"        android:id="@+id/appbar">        <android.support.design.widget.CollapsingToolbarLayout            android:id="@+id/colapsing"            android:layout_width="match_parent"            android:layout_height="match_parent"            app:layout_scrollFlags="exitUntilCollapsed|scroll"            app:contentScrim="@color/colorPrimary"            app:title="app Title"            app:expandedTitleMarginStart="48dp"            app:expandedTitleMarginEnd="64dp"            android:background="@drawable/gambarkosong">            <android.support.v7.widget.Toolbar                android:id="@+id/toolbar"                android:popupTheme="@style/AlertDialog.AppCompat.Light"                app:layout_collapseMode="pin"                android:layout_width="match_parent"                android:layout_height="?actionBarSize">            </android.support.v7.widget.Toolbar>        </android.support.design.widget.CollapsingToolbarLayout>    </android.support.design.widget.AppBarLayout>    <android.support.v4.widget.NestedScrollView        android:layout_width="match_parent"        android:layout_height="match_parent"        app:layout_behavior="@string/appbar_scrolling_view_behavior">        <LinearLayout            android:layout_width="match_parent"            android:layout_height="wrap_content">        <Button            android:layout_width="match_parent"            android:layout_height="match_parent"            android:text="agdkjagkfdakjfgvkajgdhlakdlf"/>        </LinearLayout>    </android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>