活动中的浮动操作按钮 - 如何锚定到片段中的recyclerview?

时间:2015-06-27 19:38:24

标签: android android-fragments android-viewpager android-recyclerview floating-action-button

我在这个问题Floating Action Button not showing fully inside a fragment

中遇到了同样的问题

我的activity_main中有一个tablayout和2个标签(包含不同的片段,其中一个包含recyclerView)。当我将FAB放入片段时,在我向下滚动recyclerView之前,FAB没有完全显示。

因此,我按照链接问题中的建议将我的FAB移动到coordinator_layout小部件的activity_main.xml文件中,并且它运行良好。

通过这种方式,我在活动中有一个FAB,而不是在片段中,我想知道如何将我的工厂锚定到片段中的recyclerview,例如让它在回收者滚动期间制作动画?

现在带有tablayout的activity_main.xml:

activity_main.xml中

<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.support.design.widget.AppBarLayout
        android:id="@+id/appbarlayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:fitsSystemWindows="true" >

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar1"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_scrollFlags="scroll|enterAlways"
            android:background="?attr/colorPrimary" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tabLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/toolbar1"
            android:background="?attr/colorPrimary"
            android:scrollbars="horizontal"
            app:tabMode="scrollable" />

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

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />


    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_gravity="bottom|right"
        android:layout_marginBottom="20dp"
        android:layout_marginRight="20dp"
        android:src="@drawable/ic_action_location_found"
        app:fabSize="normal" />
    </android.support.design.widget.CoordinatorLayout>

fragment.xml之

<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:padding="@dimen/activity_vertical_margin" >

    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/start_button"
        android:scrollbars="vertical" />


</RelativeLayout>

2 个答案:

答案 0 :(得分:10)

您是否尝试将其锚定到viewpager?

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    app:layout_anchor="@id/viewpager"
    app:layout_anchorGravity="bottom|right|end"
</android.support.design.widget.CoordinatorLayout>

然后你将FloatingActionButton.Behavior延伸到respond到CoordinatorLayout事件:

public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {

    public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
         super();
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout,
                                   FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
    return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL ||
            super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target,
                    nestedScrollAxes);
    }

    @Override
    public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child,
                           View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
    super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed,
            dyUnconsumed);

        if (dyConsumed > 0 && child.getVisibility() == View.VISIBLE) {
            child.hide();
         } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
             child.show();
         }
     }

 }

并将其添加到您的FloatingButton:

app:layout_behavior="com.package.yourapp.ScrollAwareFABBehavior"

这里解释得很好:

https://guides.codepath.com/android/Floating-Action-Buttons

答案 1 :(得分:2)

补充here回答:

提供的解决方案对我没有用。我有一个问题,在滚动Recyclerview列表后,FAB不再显示。 要解决此问题,我只需使用以下代码替换child.hide()

child.hide(new FloatingActionButton.OnVisibilityChangedListener() {
    @Override
    public void onHidden(FloatingActionButton fab) {
        super.onHidden(fab);
        fab.setVisibility(View.INVISIBLE);
    }
});

可在此处找到完整说明:@petrusgome's