CollapsingToolbarLayout und FloatingActionButton

Question

Ich habe CollapsingToolbarLayout und innerhalb zwei FloatingActionButtons. Diese FABs sind nur sichtbar, wenn die Toolbar erweitert ist. Wenn sie ausgeblendet ist, sind sie verborgen. Ich brauche sie sichtbar, wenn die Werkzeugleiste auch eingeklappt ist. Wie kann ich es tun?

Vielen Dank für Tipps ...

<?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" 
    android:fitsSystemWindows="true" 
    tools:context=".CalendarEventInsUpdActivity"> 

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

     <android.support.design.widget.CollapsingToolbarLayout 
      android:id="@+id/toolbar_layout" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:fitsSystemWindows="true" 
      app:contentScrim="?attr/colorPrimary" 
      app:layout_scrollFlags="scroll|exitUntilCollapsed"> 

      <android.support.v7.widget.Toolbar 
       android:id="@+id/toolbar" 
       android:layout_width="match_parent" 
       android:layout_height="?attr/actionBarSize" 
       app:layout_collapseMode="parallax" 
       app:popupTheme="@style/AppTheme.PopupOverlay"/> 

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

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

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/btnSave" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_menu_save" 
     app:backgroundTint="@android:color/holo_green_light" 
     app:layout_anchor="@id/app_bar" 
     app:layout_anchorGravity="bottom|center"/> 

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/btnCancel" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_menu_revert" 
     app:backgroundTint="@android:color/holo_red_light" 
     app:layout_anchor="@id/app_bar" 
     app:layout_anchorGravity="bottom|end"/> 

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

Answer 1

Sie eine Behavior zum FAB hinzufügen .

etwas Versuchen ähnlich wie:

public class ScrollingFABBehavior extends CoordinatorLayout.Behavior<FloatingActionButton> { 
    private int toolbarHeight; 

    public ScrollingFABBehavior(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     this.toolbarHeight = Utils.getToolbarHeight(context); 
    } 

    @Override 
    public boolean layoutDependsOn(CoordinatorLayout parent, FloatingActionButton fab, View dependency) { 
     return dependency instanceof AppBarLayout; 
    } 

    @Override 
    public boolean onDependentViewChanged(CoordinatorLayout parent, FloatingActionButton fab, View dependency) { 
     //do nothing with the fab or write your logic for the FAB 
     return true; 
    } 
} 

dann das Verhalten fügen Sie den XML-FAB-Tag

app:layout_behavior="com.example.ScrollingFABBehavior" /> 

Answer 2

Sie Fabs als direkter Nachkomme von cordinatorLayout und Verwendung Layoutverhalten, legen müssen: müssen

<android.support.design.widget.FloatingActionButton 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    app:layout_behavior="@string/appbar_scrolling_view_behavior"/> 

Answer 3

dieses xml versuchen.

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:id="@+id/main_content" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:fitsSystemWindows="true"> 

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

     <android.support.design.widget.CollapsingToolbarLayout 
      android:id="@+id/collapsing_toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      app:layout_scrollFlags="scroll|exitUntilCollapsed" 
      android:fitsSystemWindows="true" 
      app:contentScrim="?attr/colorPrimary" 
      app:expandedTitleMarginStart="48dp" 
      app:expandedTitleMarginEnd="64dp"> 



      <android.support.v7.widget.Toolbar 
       android:id="@+id/toolbar" 
       android:layout_width="match_parent" 
       android:layout_height="?attr/actionBarSize" 
       app:popupTheme="@style/ThemeOverlay.AppCompat.Light" 
       app:layout_collapseMode="pin" /> 

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

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

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

    <android.support.design.widget.FloatingActionButton 
     android:id="@+id/btnSave" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_menu_save" 
     app:backgroundTint="@android:color/holo_green_light" 
     app:layout_anchor="@id/app_bar" 
     app:layout_anchorGravity="bottom|center"/> 

     <android.support.design.widget.FloatingActionButton 
     android:id="@+id/btnCancel" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_margin="@dimen/fab_margin" 
     android:src="@android:drawable/ic_menu_revert" 
     app:backgroundTint="@android:color/holo_red_light" 
     app:layout_anchor="@id/app_bar" 
     app:layout_anchorGravity="bottom|end"/> 


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