Question

我使用folloaing代码创建可折叠的工具栏布局

<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:background="#EEEEEE"
android:fitsSystemWindows="true">

<android.support.v4.widget.NestedScrollView
    android:id="@+id/scroll"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipToPadding="false"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/appbar_layout"
        android:orientation="vertical">

    </LinearLayout>
</android.support.v4.widget.NestedScrollView>

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar_layoutdetails"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:fitsSystemWindows="true"
    android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/toolbarCollapse"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        android:minHeight="?attr/actionBarSize"
        app:contentScrim="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:navigationIcon="?attr/homeAsUpIndicator"
        app:title="Fealty"
        app:titleEnabled="true">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <ImageView
                android:id="@+id/imageView8"
                android:layout_width="match_parent"
                android:layout_height="190dp"
                android:background="@android:color/darker_gray"
                android:minHeight="190dp"
                android:scaleType="fitXY"
                android:src="@drawable/mlogin"
                app:layout_collapseMode="parallax"/>

            <TextView
                android:id="@+id/title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentLeft="true"
                android:layout_alignParentStart="true"
                android:layout_alignTop="@+id/favourite"
                android:layout_gravity="bottom|end"
                android:layout_marginEnd="20dp"
                android:layout_marginLeft="16dp"
                android:layout_marginRight="16dp"
                android:layout_marginStart="16dp"
                android:layout_toLeftOf="@+id/favourite"
                android:layout_toStartOf="@+id/favourite"
                android:src="@drawable/ic_launcher"
                android:text="App Name"
                android:textAppearance="?android:attr/textAppearanceMedium"
                app:layout_anchor="@+id/app_bar_layout"
                app:layout_anchorGravity="bottom|end"/>

            <android.support.design.widget.FloatingActionButton
                android:id="@+id/favourite"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignTop="@+id/share"
                android:layout_gravity="bottom|end"
                android:layout_marginEnd="20dp"
                android:layout_marginLeft="16dp"
                android:layout_marginRight="16dp"
                android:layout_toLeftOf="@+id/share"
                android:layout_toStartOf="@+id/share"
                android:src="@drawable/heart_out"
                app:backgroundTint="#E91E63"
                app:borderWidth="0dp"
                app:fabSize="mini"
                app:layout_anchor="@+id/app_bar_layout"
                app:layout_anchorGravity="bottom|end"/>

            <android.support.design.widget.FloatingActionButton
                android:id="@+id/share"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignBottom="@+id/imageView8"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_gravity="bottom|end"
                android:layout_marginBottom="29dp"
                android:layout_marginEnd="23dp"
                android:layout_marginLeft="16dp"
                android:layout_marginRight="16dp"
                android:src="@drawable/ic_launcher"
                app:backgroundTint="#E91E63"
                app:borderWidth="0dp"
                app:fabSize="mini"
                app:layout_anchor="@+id/app_bar_layout"
                app:layout_anchorGravity="bottom|end"/>

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?actionBarSize"
                android:minHeight="?attr/actionBarSize"
                app:navigationIcon="?attr/homeAsUpIndicator"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
            </android.support.v7.widget.Toolbar>
        </RelativeLayout>
    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>

问题是，当可折叠工具栏不处于可折叠状态时，后退箭头是可见的，但如果折叠后，后退箭头不可见。为什么这样？

Answer 1

在CoordinatorLayout中删除此android:fitsSystemWindows="true"。

在下面的setContentView

中添加此内容

Toolbar toolbar = (Toolbar) findViewById(R.id.mainToolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowTitleEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);

折叠工具栏时不显示后退箭头

1 个答案: