如何在RecyclerView中使用ItemAnimator?

问题描述

当我从recyclerview的适配器中添加或删除某项时，我想做动画.我正在尝试按以下方式使用RecyclerView.ItemAnimator，但无法正常工作.

I want to do animation when an item is added or removed from adapter of recyclerview. I'am trying to use RecyclerView.ItemAnimator as follows but it is not working..

    public class MyAnimator extends RecyclerView.ItemAnimator{

    @Override
    public boolean animateAdd(ViewHolder arg0) {
        Log.d("test","Added Animation");
        return false;
    }

    @Override
    public boolean animateChange(ViewHolder arg0, ViewHolder arg1, int arg2, int arg3, int arg4, int arg5) {
        Log.d("test","Change Animation");
        return false;
    }

    @Override
    public boolean animateMove(ViewHolder arg0, int arg1, int arg2, int arg3, int arg4) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public boolean animateRemove(ViewHolder arg0) {
        Log.d("test", "Remove Animation");
        return false;
    }

    @Override
    public void endAnimation(ViewHolder arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void endAnimations() {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean isRunning() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void runPendingAnimations() {
        // TODO Auto-generated method stub

    }

}

我正在使用上面的代码，如下所示.

I'am using above code as follows.

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

    mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

    data=new ArrayList<String>();


    // use a linear layout manager
    mLayoutManager = new LinearLayoutManager(this);
    mRecyclerView.setLayoutManager(mLayoutManager);

    animator = new MyAnimator();
    mRecyclerView.setItemAnimator(animator);

    mAdapter = new MyAdapter(data);
    mRecyclerView.setAdapter(mAdapter);

}

每当我将新项目添加到数据集并调用mAdapter.notifyDataSetChanged()时，我都希望MyAnimator类中的animateAdd(ViewHolder arg0)中存在日志.但它没有来.我错过了什么.为什么它不起作用.

Whenever i add a new item into dataset and call mAdapter.notifyDataSetChanged() i expected the Log present in animateAdd(ViewHolder arg0) present in MyAnimator class; but it's not coming..am i missing something..Why its not working.

推荐答案

首先，您不需要为此自定义ItemAnimator.您可以使用默认值之一，删除mRecyclerView.setItemAnimator(animator);

First of all, you don't need custom ItemAnimator for that. You can use default one, remove mRecyclerView.setItemAnimator(animator);

此外，您还必须使用notifyItemInserted()和notifyItemRemoved()而不是notifyDataSetChanged()，它会为您调用适当的动画.

Also, you have to use notifyItemInserted() and notifyItemRemoved() instead of notifyDataSetChanged(), it invokes proper animation for you.

这篇关于如何在RecyclerView中使用ItemAnimator?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！