Android RecyclerView item选中放大被遮挡问题详解
发布时间：2020-10-04 00:53:24
来源：
阅读：190
作者：lbcab
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());
(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;
}
}
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.
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipChildren="false"
android:clipToPadding="false">
android:layout_width="match_parent"
android:layout_height="245dp"
android:layout_centerInParent="true" />
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) {
(gainFocus, direction, previouslyFocusedRect);
if (gainFocus) {
getRootView().invalidate();
zoomOut();
} else {
zoomIn();
}
}
private void zoomIn() {
if (scaleSmallAnimation == null) {
scaleSmallAnimation = (getContext(), .anim_scale_small);
}
startAnimation(scaleSmallAnimation);
}
private void zoomOut() {
if (scaleBigAnimation == null) {
scaleBigAnimation = (getContext(), .anim_scale_big);
}
startAnimation(scaleBigAnimation);
}
}
(2) 放大动画xml配置如下:
android:fillAfter="true"
android:shareInterpolator="false">
android:duration="150"
android:fromXScale="1.0"
android:fromYScale="1.0"
android:interpolator="@android:anim/accelerate_decelerate_interpolator"
android:pivotX="50.0%"
android:pivotY="50.0%"
android:repeatCount="0"
android:toXScale="1.08"
android:toYScale="1.08" />
(3) 主布局xml:
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipChildren="false"
android:clipToPadding="false">
android:
android:layout_width="match_parent"
android:layout_height="210dp"
android:layout_centerInParent="true"/>
(4) 子视图的xml:
android:
android:layout_width="300dp"
android:layout_height="210dp"
android:focusable="true">
android:layout_width="300dp"
android:layout_height="30dp"
android:layout_alignParentBottom="true" />
(5) adapter配置:
public class MyAdapter extends {
private Context mContext;
private OnItemStateListener mListener;
private static int[] mColorIds = {, , ,
, , , ,
, , , , };
MyAdapter(Context context) {
mContext = context;
}
public void setOnItemStateListener(OnItemStateListener listener) {
mListener = listener;
}
@Override
public onCreateViewHolder(ViewGroup parent, int viewType) {
return new RecyclerViewHolder((mContext, .item_recyclerview, null));
}
@Override
public void onBindViewHolder( holder, final int position) {
final RecyclerViewHolder viewHolder = (RecyclerViewHolder) holder;
((mContext, mColorIds[position]));
}
@Override
public int getItemCount() {
return ;
}
private class RecyclerViewHolder extends implements {
FocusRelativeLayout mRelativeLayout;
RecyclerViewHolder(View itemView) {
super(itemView);
mRelativeLayout = (FocusRelativeLayout) (.rl_main_layout);
(this);
}
@Override
public void onClick(View v) {
if (mListener != null) {
(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) {
(savedInstanceState);
setContentView(.activity_recycler);
final ScaleRecyclerView recyclerView = (ScaleRecyclerView) findViewById(.main_recyclerView);
GridLayoutManager manager = new GridLayoutManager(, 1);
();
();
(manager);
int itemSpace = getResources().
getDimensionPixelSize(.recyclerView_item_space);
(new SpaceItemDecoration(itemSpace));
final MyAdapter mAdapter = new MyAdapter();
(mAdapter);
}
private class SpaceItemDecoration extends {
private int space;
SpaceItemDecoration(int space) {
= space;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
state) {
= space;
}
}
}
效果图如下:
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持亿速云。