原文地址： Android RecyclerView item选中放大被遮挡问题
在Android TV上一般选中某个View, 都会有焦点突出放大的效果, 但是当在RecyclerView中(ListView或GridView)实现当item View执行放大动画后会被其他的item View遮挡. 原因是: RecyclerView的机制是越靠后的View z-order越高, 所以bringToFront方法是不管用的.在实现针对TV端的自定义控件 TvRecyclerView 时遇到此问题, 最后的解决方案是: 自定义RecyclerView, 重写getChildDrawingOrder方法, 让选中的item最后绘制, 这样就不会让其他view遮挡.public class ScaleRecyclerView extends RecyclerView { private int mSelectedPosition = 0; public ScaleRecyclerView(Context context) { super(context); init(); } public ScaleRecyclerView(Context context, @Nullable AttributeSet attrs) { super(context, attrs); init(); } public ScaleRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } private void init() { //启用子视图排序功能 setChildrenDrawingOrderEnabled(true); } @Override public void onDraw(Canvas c) { mSelectedPosition = getChildAdapterPosition(getFocusedChild()); super.onDraw(c); } @Override protected int getChildDrawingOrder(int childCount, int i) { int position = mSelectedPosition; if (position < 0) { return i; } else { if (i == childCount - 1) { if (position > i) { position = i; } return position; } if (i == position) { return childCount - 1; } } return i; }}1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484912345678910111213141516171819202122232425262728293031323334353637383940414243444546474849最好还需要设置RecyclerView的父类的属性: clipChildren = false, clipToPadding = false, 避免边缘的子view被父类遮挡.123456789101112123456789101112使用介绍: (1) 自定具有放大缩小的布局:public class FocusRelativeLayout extends RelativeLayout { private Animation scaleSmallAnimation; private Animation scaleBigAnimation; public FocusRelativeLayout(Context context) { super(context); } public FocusRelativeLayout(Context context, AttributeSet attrs) { super(context, attrs); } public FocusRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); } @Override protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); if (gainFocus) { getRootView().invalidate(); zoomOut(); } else { zoomIn(); } } private void zoomIn() { if (scaleSmallAnimation == null) { scaleSmallAnimation = AnimationUtils.loadAnimation(getContext(), R.anim.anim_scale_small); } startAnimation(scaleSmallAnimation); } private void zoomOut() { if (scaleBigAnimation == null) { scaleBigAnimation = AnimationUtils.loadAnimation(getContext(), R.anim.anim_scale_big); } startAnimation(scaleBigAnimation); }}123456789101112131415161718192021222324252627282930313233343536373839404142123456789101112131415161718192021222324252627282930313233343536373839404142(2) 放大动画xml配置如下:123456789101112131415123456789101112131415(3) 主布局xml:12345678910111213141234567891011121314(4) 子视图的xml:12345678910111234567891011(5) adapter配置:public class MyAdapter extends RecyclerView.Adapter{
private Context mContext;
private OnItemStateListener mListener;
private static int[] mColorIds = {R.color.amber, R.color.brown, R.color.cyan,
R.color.deepPurple, R.color.green, R.color.lightBlue, R.color.lightGreen,
R.color.lime, R.color.orange, R.color.pink, R.color.cyan, R.color.deepPurple};
MyAdapter(Context context) {
mContext = context;
}
public void setOnItemStateListener(OnItemStateListener listener) {
mListener = listener;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new RecyclerViewHolder(View.inflate(mContext, R.layout.item_recyclerview, null));
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
final RecyclerViewHolder viewHolder = (RecyclerViewHolder) holder;
viewHolder.mRelativeLayout.setBackgroundColor(ContextCompat.getColor(mContext, mColorIds[position]));
}
@Override
public int getItemCount() {
return mColorIds.length;
}
private class RecyclerViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
FocusRelativeLayout mRelativeLayout;
RecyclerViewHolder(View itemView) {
super(itemView);
mRelativeLayout = (FocusRelativeLayout) itemView.findViewById(R.id.rl_main_layout);
mRelativeLayout.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (mListener != null) {
mListener.onItemClick(v, getAdapterPosition());
}
}
}
public interface OnItemStateListener {
void onItemClick(View view, int position);
}
}
(6) Activity中的配置:
public class RecyclerActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recycler);
final ScaleRecyclerView recyclerView = (ScaleRecyclerView) findViewById(R.id.main_recyclerView);
GridLayoutManager manager = new GridLayoutManager(RecyclerActivity.this, 1);
manager.setOrientation(LinearLayoutManager.HORIZONTAL);
manager.supportsPredictiveItemAnimations();
recyclerView.setLayoutManager(manager);
int itemSpace = getResources().
getDimensionPixelSize(R.dimen.recyclerView_item_space);
recyclerView.addItemDecoration(new SpaceItemDecoration(itemSpace));
final MyAdapter mAdapter = new MyAdapter(RecyclerActivity.this);
recyclerView.setAdapter(mAdapter);
}
private class SpaceItemDecoration extends RecyclerView.ItemDecoration {
private int space;
SpaceItemDecoration(int space) {
this.space = space;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
RecyclerView.State state) {
outRect.left = space;
}
}
}
效果图如下:
这里写图片描述
