java - Animate Recycler逐个查看项目

Question

我正在尝试为我的应用程序中的 RecyclerView 项目设置动画。我尝试在我的适配器中使用这段代码:

    public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
    {
        myHolder = holder as MyView;
        if (position > mCurrentPosition)
        {
            int currentAnim = Android.Resource.Animation.SlideInLeft;
            SetAnimation(holder.ItemView, currentAnim);
            mCurrentPosition = position;
        }

    }

    private void SetAnimation(View view, int currentAnim)
    {

        Animation anim = AnimationUtils.LoadAnimation(mContext, currentAnim);
        anim.SetInterpolator(mContext, Android.Resource.Interpolator.Bounce);
        view.StartAnimation(anim);
    }

但是，因为我的所有项目在创建 View 时一起出现，而不是在用户单击按钮时添加，例如，所有项目一起动画。

我希望这些项目按照它们的位置依次进行动画处理。
这怎么可能？

Answer 1

这个怎么样:

public override void OnBindViewHolder(RecyclerView.ViewHolder holder, int position)
{
    myHolder = holder as MyView;
    if (position > mCurrentPosition)
    {
        Handler h = new Handler();
        int currentAnim = Android.Resource.Animation.SlideInLeft;
        Action myAction = () => 
        {
            SetAnimation(holder.ItemView, currentAnim);
        };

        h.PostDelayed(myAction, 1000);


        mCurrentPosition = position;
    }

}

更新:如果您想按顺序为所有项目设置动画，您应该将逻辑代码放在适配器之外。
比如activity中，为RecyleView设置adapter后

   List<YourObject> data; // your data list for RecycleView

   // CALL this code after set adapter for RecycleView
   Handler h = new Handler();
   int currentAnim = Android.Resource.Animation.SlideInLeft;
   Action myAction = () => 
   {     
      // assume you use LinearLayoutManager  for RecyecleView
        View itemView = linearLayoutManager.findViewByPosition(0);
        StartAnimation(itemView, 0);
   };

   h.PostDelayed(myAction, 1000);


   private void StartAnimation(View view, int position)
    {

        Animation anim = AnimationUtils.LoadAnimation(mContext, currentAnim);
        anim.SetInterpolator(mContext, Android.Resource.Interpolator.Bounce);
        view.StartAnimation(anim);
        anim.AnimationEnd += (sender, e) =>
        {
            // animate next item

            ++position;
            if (position < data.size()) // data is your array list
            {

                // assume you use LinearLayoutManager  for RecyecleView
                View itemView = linearLayoutManager.findViewByPosition(position);
                if (itemView != null)
                {
                    StartAnimation(itemView, position);
                }
            }
        }
    }