相关疑难解决方法(0)

我正在尝试使用a RecyclerView作为横向ListView.我试图弄清楚如何突出显示所选项目.当我点击其中一个项目时,它会被选中并正确突出显示,但是当我点击另一个项目时,第二个项目会被旧项目突出显示.

这是我的onClick函数:

@Override
public void onClick(View view) {

    if(selectedListItem!=null){
        Log.d(TAG, "selectedListItem " + getPosition() + " " + item);
        selectedListItem.setBackgroundColor(Color.RED);
    }
    Log.d(TAG, "onClick " + getPosition() + " " + item);
    viewHolderListener.onIndexChanged(getPosition());
    selectedPosition = getPosition();
    view.setBackgroundColor(Color.CYAN); 
    selectedListItem = view;
}

这是onBindViewHolder:

@Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {   
    viewHolder.setItem(fruitsData[position]);
    if(selectedPosition == position)
        viewHolder.itemView.setBackgroundColor(Color.CYAN);    
    else
        viewHolder.itemView.setBackgroundColor(Color.RED);

}

我正在试验支持库的recyclerview和卡片.我有回收卡的卡片.每张卡片的右上角都有一个"x"图标可将其删除:

该卡的xml, list_item.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="5dp">
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:id="@+id/taskDesc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:textSize="40sp"
        android:text="hi"/>
    <ImageView
        android:id="@+id/xImg"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_alignParentRight="true"
        android:src="@drawable/ic_remove"/>
</RelativeLayout>
</android.support.v7.widget.CardView>

我试图用我会在使用的位置标记的行notifyItemRemoved(position)中TaskAdapter.java:

public class TaskAdapter extends RecyclerView.Adapter<TaskAdapter.TaskViewHolder>  {

private List<Task> taskList;
private TaskAdapter thisAdapter = this;


// cache of views to reduce number of findViewById calls
public static class TaskViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    protected TextView taskTV;
    protected ImageView closeBtn;
    public TaskViewHolder(View v) {
        super(v); …

我有一个应用程序,我需要适应Android TV.此应用程序包含水平RecyclerView,当我按遥控器上的D-pad按钮时它不会滚动.我找到了这个解决方案,但它崩溃了.这是代码:

<ru.myapp.package.HorizontalPersistentFocusWrapper
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
       <android.support.v7.widget.RecyclerView
           android:id="@+id/recycler_view"
           android:layout_width="match_parent"
           android:layout_height="250dp"
           android:background="@null"
           android:scrollbars="none"/>
</ru.myapp.package.HorizontalPersistentFocusWrapper>

Horizo​​ntalPersistentFocusWrapper与PersistentFocusWrapper相同,但mPersistFocusVertical = false;

在这个地方发生崩溃:

@Override
    public void requestChildFocus(View child, View focused) {
        super.requestChildFocus(child, focused);
        View view = focused;
        while (view != null && view.getParent() != child) {
            view = (View) view.getParent(); <<<------ Crash here
        }
        mSelectedPosition = view == null ? -1 : ((ViewGroup) child).indexOfChild(view);
        if (DEBUG) Log.v(TAG, "requestChildFocus focused " + focused + " mSelectedPosition " + mSelectedPosition);
    }

崩溃堆栈跟踪:

java.lang.ClassCastException: android.view.ViewRootImpl cannot …