Question

我有一个LinearLayout，默认情况下在此android:visibility="gone"中用LinearLayout设置，我有一个RecyclerView用我的活动的onCreate()方法初始化。 / p>

将LinearLayout设置为android:visibility="visible"时，RecyclerView不会显示其项目...

经过几天的思考，我来告诉我这个问题是由于在LinearLayout中添加项目时RecyclerView不可见，或者是由于LinearLayout是使用Utils.expand(View view)和Utils.collapse(View view)方法动画的，但是我仍然不能解决我的问题...

XML-activity_main.xml

<Button
     android:id="@+id/activityMain_button_filter"

     android:layout_width="wrap_content"
     android:layout_height="wrap_content"

     android:text="@string/activityMain_button_filter"
     android:textColor="@color/colorBlackOverlay"
     android:textAllCaps="false"
     style="?android:attr/buttonBarButtonStyle"

     android:drawableRight="@drawable/vector_icon_expand"
     android:drawableEnd="@drawable/vector_icon_expand"
     android:drawablePadding="@dimen/content_padding_small"

     android:layout_alignParentRight="true"
     android:layout_alignParentEnd="true" />

<android.support.v4.widget.NestedScrollView
     android:layout_width="match_parent"
     android:layout_height="wrap_content">

     <LinearLayout
          android:id="@+id/activityMain_linearLayout_filter"

          android:layout_width="match_parent"
          android:layout_height="match_parent"

          android:orientation="vertical"
          android:background="@color/colorCloudGray"

          android:paddingTop="@dimen/content_padding_normal"                   
          android:paddingLeft="@dimen/activity_horizontal_padding"                   
          android:paddingRight="@dimen/activity_horizontal_padding"                   
          android:paddingBottom="@dimen/content_padding_normal"

          android:visibility="gone">

          <!-- Others views -->

          <android.support.v7.widget.RecyclerView

               android:id="@+id/activityMain_recyclerView_filterLocation"

               android:layout_width="match_parent"
               android:layout_height="wrap_content"

               android:orientation="horizontal"

               app:layoutManager="android.support.v7.widget.StaggeredGridLayoutManager"
               app:spanCount="1"

               android:descendantFocusability="blocksDescendants" />

          <!-- Others views -->

     </LinearLayout>

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

JAVA-MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button buttonFilter = findViewById(R.id.activityMain_button_filter);
        final LinearLayout linearLayoutFilter = findViewById(R.id.activityMain_linearLayout_filter);
        RecyclerView recyclerFilterLocation = findViewById(R.id.activityMain_recyclerView_filterLocation);

        final RecyclerLocationAdapter recyclerLocationAdapter = new RecyclerLocationAdapter(new ArrayList<>(filterLocation));

        recyclerFilterLocation.setNestedScrollingEnabled(false);
        recyclerFilterLocation.setHasFixedSize(true);
        recyclerFilterLocation.setAdapter(recyclerLocationAdapter);

        buttonFilter.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 if (linearLayoutFilter.getVisibility() == View.GONE) {
                      Utils.expandView(linearLayoutFilter);
                 } 
                 else {
                      Utils.collapseView(linearLayoutFilter);
                 }
             }
         }
    }
}

JAVA-Utils.java

public class Utils {

     public static void expandView(final View view) {
        view.measure(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        final int targetHeight = view.getMeasuredHeight();
        view.getLayoutParams().height = 1;
        view.setVisibility(View.VISIBLE);

        Animation animation = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                view.getLayoutParams().height = interpolatedTime == 1
                        ? LinearLayout.LayoutParams.WRAP_CONTENT
                        : (int) (targetHeight * interpolatedTime);
                view.requestLayout();
            }

            @Override
            public boolean willChangeBounds() {
                return true;
            }
        };

        animation.setDuration((int) (targetHeight / view.getContext().getResources().getDisplayMetrics().density));
        view.startAnimation(animation);
    }

    public static void collapseView(final View view) {
        final int initialHeight = view.getMeasuredHeight();

        Animation animation = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                if (interpolatedTime == 1) {
                    view.setVisibility(View.GONE);
                } else {
                    view.getLayoutParams().height = initialHeight - (int) (initialHeight * interpolatedTime);
                    view.requestLayout();
                }
            }

            @Override
            public boolean willChangeBounds() {
                return true;
            }
        };

        animation.setDuration((int) (initialHeight / view.getContext().getResources().getDisplayMetrics().density));
        view.startAnimation(animation);
    }

}

谢谢您的帮助！

android recyclerview不显示项目

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