折叠式状态栏（ToolBar）

用到控件：

CoordinatorLayout  AppBarLayout  CollapsingToolbarLayout  Toolbar

初始化控件：

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    View view = LayoutInflater.from(this).inflate(R.layout.includ,null);
    toolbar.addView(view);// 为toolBar设置自定义View
    View  contentView = toolbar.getRootView();
    TextView textView = (TextView) contentView.findViewById(R.id.text);
    textView.setText("新的内容");

布局文件：

<?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"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true">

    <android.support.design.widget.AppBarLayout
            android:id="@+id/app_bar"
            android:fitsSystemWindows="true"
            android:layout_height="@dimen/app_bar_height"
            android:layout_width="match_parent"
            android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.design.widget.CollapsingToolbarLayout
                android:id="@+id/toolbar_layout"
                android:fitsSystemWindows="true"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                app:layout_scrollFlags="scroll|exitUntilCollapsed"
                app:contentScrim="?attr/colorPrimary">
            <ImageView android:layout_width="match_parent"
                       android:layout_height="match_parent"
                       android:scaleType="centerCrop"
                       android:src="@mipmap/ic_launcher"
                       app:layout_collapseMode="pin"
                       app:layout_collapseParallaxMultiplier="0.5"
            />
            <android.support.v7.widget.Toolbar
                    android:id="@+id/toolbar"
                    android:layout_height="?attr/actionBarSize"
                    android:layout_width="match_parent"
                    app:layout_collapseMode="pin">
            </android.support.v7.widget.Toolbar>

        </android.support.design.widget.CollapsingToolbarLayout>
    </android.support.design.widget.AppBarLayout>

    <include layout="@layout/content_scrolling"/>


</android.support.design.widget.CoordinatorLayout>