Question

我有一个带有Recyclerview的屏幕和LinearLayout中的其他元素。问题是当我删除RecyclerView的一个项目时，animateLayoutChanges在这种情况下不起作用。 anayone知道为什么会这样吗？

XML

<LinearLayout
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"
tools:context="com.example.alvaro.resizetest.MainActivity">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:animateLayoutChanges="true"
    android:orientation="vertical">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <LinearLayout
        android:id="@+id/test1"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorAccent"
        android:gravity="center_vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="LinearLayout"
            android:textColor="#FFFFFF"
            android:textSize="22sp"/>
    </LinearLayout>


    <LinearLayout
        android:id="@+id/test2"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorPrimaryDark"
        android:gravity="center_vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="LinearLayout"
            android:textColor="#FFFFFF"
            android:textSize="22sp"/>
    </LinearLayout>


    <LinearLayout
        android:id="@+id/test3"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorAccent"
        android:gravity="center_vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="LinearLayout"
            android:textColor="#FFFFFF"
            android:textSize="22sp"/>
    </LinearLayout>


    <LinearLayout
        android:id="@+id/test4"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="@color/colorPrimaryDark"
        android:gravity="center_vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="LinearLayout"
            android:textColor="#FFFFFF"
            android:textSize="22sp"/>
    </LinearLayout>


</LinearLayout>

JAVA

public class MainActivity extends AppCompatActivity {

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

    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);

    Adapter adapter = new Adapter();

    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(adapter);
    recyclerView.setNestedScrollingEnabled(true);

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            view.setVisibility(View.GONE);
        }
    };

    findViewById(R.id.test1).setOnClickListener(listener);
    findViewById(R.id.test2).setOnClickListener(listener);
    findViewById(R.id.test3).setOnClickListener(listener);
    findViewById(R.id.test4).setOnClickListener(listener);

}


class Adapter extends RecyclerView.Adapter<Adapter.Holder>{

    int size = 3;

    public Adapter() {
    }

    @Override
    public Holder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = getLayoutInflater().inflate(R.layout.item, parent, false);

        return new Holder(view);
    }

    @Override
    public void onBindViewHolder(Holder holder, int position) {

    }

    @Override
    public int getItemCount() {
        return size;
    }

    class Holder extends RecyclerView.ViewHolder {

        public Holder(final View itemView) {
            super(itemView);

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    size --;
                    notifyItemRemoved(getAdapterPosition());
                }
            });

        }
    }
}

Answer 1

过了一会儿我得到了一个解决方案。我创建了一个函数来为recyclerView高度设置动画。

<强> JAVA

public class MainActivity extends AppCompatActivity {

private final String TAG = MainActivity.class.getSimpleName();

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

    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);

    Adapter adapter = new Adapter(recyclerView);

    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this) {
        @Override
        public boolean canScrollVertically() {
            return false;
        }
    };

    recyclerView.setLayoutManager(linearLayoutManager);
    recyclerView.setAdapter(adapter);
    recyclerView.setNestedScrollingEnabled(true);

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            view.setVisibility(View.GONE);
        }
    };

    findViewById(R.id.test1).setOnClickListener(listener);
    findViewById(R.id.test2).setOnClickListener(listener);
    findViewById(R.id.test3).setOnClickListener(listener);
    findViewById(R.id.test4).setOnClickListener(listener);

}


public void animateHeight(final View v, final int height) {

    final int initialHeight = v.getMeasuredHeight();
    int duration = 500;
    Interpolator interpolator = new AccelerateInterpolator(2);

    // I have to set the same height before the animation because there is a glitch
    // in the beginning of the animation
    v.getLayoutParams().height = initialHeight;
    v.requestLayout();

    Animation a = new Animation() {
        @Override
        protected void applyTransformation(float interpolatedTime, Transformation t) {
            Log.d(TAG, "InterpolatedTime: " + interpolatedTime);
            Log.d(TAG, "Collapsing height: " + (initialHeight - (int) (height * interpolatedTime)));
            v.getLayoutParams().height = initialHeight - (int) (height * interpolatedTime);
            v.requestLayout();
        }

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

    a.setDuration(duration);
    a.setInterpolator(interpolator);
    v.startAnimation(a);
}


class Adapter extends RecyclerView.Adapter<Adapter.Holder> {

    RecyclerView mRecyclerView;
    int size = 3;

    public Adapter(RecyclerView recyclerView) {
        mRecyclerView = recyclerView;
    }

    @Override
    public Holder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = getLayoutInflater().inflate(R.layout.item, parent, false);

        return new Holder(view);
    }

    @Override
    public void onBindViewHolder(Holder holder, int position) {

    }

    @Override
    public int getItemCount() {
        return size;
    }

    class Holder extends RecyclerView.ViewHolder {

        public Holder(final View itemView) {
            super(itemView);

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    size--;
                    notifyItemRemoved(getAdapterPosition());
                    animateHeight((View) itemView.getParent(), itemView.getMeasuredHeight());
                }
            });

        }
    }
}

}

Answer 2

对我有用的只是将以下代码添加到onCreate：

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
    ((ViewGroup) findViewById(R.id.llRoot)).getLayoutTransition()
        .enableTransitionType(LayoutTransition.CHANGING);
}

其中llRoot是包含RecyclerView的LinearLayout。

您需要在LinearLayout上保留android:animateLayoutChanges="true"，否则会崩溃。

我相信如果你想在JellyBean下面支持这个，你需要自定义解决方案。

解决方案的解释如下：https://proandroiddev.com/the-little-secret-of-android-animatelayoutchanges-e4caab2fddec

AnimateLayoutChanges不适用于RecyclerView

2 个答案: