So verhindern Sie, dass das Scrolling in CollapsingToolbarLayout gestoppt wird, wenn es die oberste Ebene erreicht

Question

In einem CoordinatorLayout wird der Bildlauf gestoppt, wenn der Wert oben erreicht wird. Der Benutzer muss also erneut scrollen, um das Bild zu sehen. Ist es möglich, weiter zu scrollen, bis das Bild vollständig angezeigt wird?

<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="com.example.murat.coordinatorlayouttest.ScrollingActivity"> 

<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/collapsing_toolbar" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:fitsSystemWindows="true" 
     app:contentScrim="?attr/colorPrimary" 
     app:expandedTitleMarginEnd="64dp" 
     app:expandedTitleMarginStart="48dp" 
     app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"> 

     <android.support.v7.widget.Toolbar 
      android:id="@+id/toolbar" 
      android:layout_width="match_parent" 
      android:layout_height="?attr/actionBarSize" 
      app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed"/> 
     <ImageView 
      android:src="@drawable/poster" 
      app:layout_scrollFlags="scroll|enterAlways|enterAlwaysCollapsed" 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:scaleType="centerCrop" 
      app:layout_collapseMode="parallax" 
      android:minHeight="200dp"/> 

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

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

Answer 1

Sie müssen die Höhe des NestedScrollView berechnen. Zuerst Aktualisieren Sie Ihr XML-Layout und fügen Sie diese Eigenschaften in der Symbolleiste hinzu und stellen Sie sicher, dass <includelayout="@layout/content_scrolling" />NestedScrollView ist und Scrolling View-Verhalten hat.

app:layout_scrollFlags="scroll|exitUntilCollapsed" 
app:layout_collapseMode="pin" 

Definieren Sie diese globalen Variablen in Ihrer Aktivität.

private int screenHeight; 
    private int linearLayoutHeight; 
    private int toolbarHeight_org; 
    private int toolbarHeight; 

diese Aktivität in onCreate Methode Do

screenHeight = getScreenHeight(this); 

    TypedValue typedValue = new TypedValue(); 
    getTheme().resolveAttribute(R.attr.colorPrimary, typedValue, true); 
    final int colorPrimary = typedValue.data; 

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

    AppBarLayout appbar = (AppBarLayout) findViewById(R.id.appbar); 
    final CoordinatorLayout.LayoutParams appbarLayoutParams = (CoordinatorLayout.LayoutParams)appbar.getLayoutParams(); 

    final ViewGroup.LayoutParams toolbarLayoutParams = toolbar.getLayoutParams(); 
    if (toolbarLayoutParams != null) { 
     toolbarHeight_org = toolbarLayoutParams.height; 
     toolbarHeight = toolbarLayoutParams.height; 
    } 

    final CollapsingToolbarLayout collapsingToolbar = 
      (CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar); 
    collapsingToolbar.setTitle(cheeseName); 

    collapsingToolbar.setContentScrimColor(colorPrimary); 
    collapsingToolbar.setExpandedTitleTextAppearance(R.style.ExpandedTitleTextAppearance); 
    //collapsingToolbar.setCollapsedTitleTextAppearance(R.style.CollapsedTitleTextAppearance); 

    final LinearLayout linearLayout = (LinearLayout) findViewById(R.id.linearLayout1); 
    ViewTreeObserver observer = linearLayout.getViewTreeObserver(); 
    observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { 
     @Override 
     public void onGlobalLayout() { 
      linearLayoutHeight = linearLayout.getHeight(); 
      if (linearLayoutHeight + toolbarHeight < screenHeight) { 
       if (toolbarLayoutParams != null) { 
        toolbarLayoutParams.height = screenHeight - linearLayoutHeight - 20; 
        if (toolbarLayoutParams.height < toolbarHeight_org) { 
         toolbarLayoutParams.height = toolbarHeight_org; 
        } 

        int extended_text_size = (int) getResources().getDimension(R.dimen.expanded_text_size); 

        if (appbarLayoutParams.height - toolbarLayoutParams.height <= extended_text_size) { 
         int value = appbarLayoutParams.height - toolbarLayoutParams.height; 
         if (value < 0) { 
          appbarLayoutParams.height = toolbarLayoutParams.height - value + extended_text_size * 3; 
         } else { 
          appbarLayoutParams.height = toolbarLayoutParams.height + extended_text_size * 3; 
         } 
         if (appbarLayoutParams.height >= screenHeight) { 
          appbarLayoutParams.height = screenHeight; 
         } 
        } 

        // collapsingToolbar.setContentScrimColor(getResources().getColor(android.R.color.transparent)); 
        if (toolbarLayoutParams.height > toolbarHeight_org) { 
         collapsingToolbar.setContentScrimColor(ContextCompat.getColor(mContext, android.R.color.transparent)); 
        } 
       } 
      } 
      // Removes the listener if possible 
      ViewTreeObserver viewTreeObserver = linearLayout.getViewTreeObserver(); 
      if (viewTreeObserver.isAlive()) { 
       if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) { 
        linearLayout.getViewTreeObserver().removeGlobalOnLayoutListener(this); 
       } else { 
        linearLayout.getViewTreeObserver().removeOnGlobalLayoutListener(this); 
       } 
      } 
     } 
    }); 
    appbar.setExpanded(true); 
} 

Get Methode Bildschirmhöhe ist

private int getScreenHeight(Context context) { 
    int measuredHeight; 
    Point size = new Point(); 
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); 

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) { 
     wm.getDefaultDisplay().getSize(size); 
     measuredHeight = size.y; 
    } else { 
     Display d = wm.getDefaultDisplay(); 
     measuredHeight = d.getHeight(); 
    } 

    return measuredHeight; 
} 

die komplette XML-Layout-Aktivität liegt bei Ihnen freundlich aktualisieren gemäß dieser

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

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

     <ImageView 
      android:id="@+id/backdrop" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:fitsSystemWindows="false" 
      android:scaleType="centerCrop" 
      app:layout_collapseMode="parallax" /> 

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

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

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

<android.support.v4.widget.NestedScrollView 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"    
    app:layout_behavior="@string/appbar_scrolling_view_behavior"> 

    <LinearLayout 
     android:id="@+id/linearLayout1" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:orientation="vertical"> 

     <android.support.v7.widget.CardView 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content" 
      android:layout_margin="@dimen/card_margin"> 

      <LinearLayout 
       style="@style/Widget.CardContent" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content"> 

       <TextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:text="Info" 
        android:textAppearance="@style/TextAppearance.AppCompat.Title" /> 

       <TextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/cheese_ipsum" /> 

      </LinearLayout> 

     </android.support.v7.widget.CardView> 

    </LinearLayout> 

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