相关疑难解决方法(0)

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); …

我在github上使用它实现了SearchView + Recyclerview.GITHUB
我的下一步是将物品放在recyclerview上的选定部分.
然后我看到一些代码让孩子进入recyclerview.
当getChildAt(index)= 0时,代码正在运行.
但是当我把索引= 12或更大时.
该计划崩溃了.

mRecyclerView.setAdapter(mAdapter);
        mRecyclerView.addOnItemTouchListener(
                new RecyclerItemClickListener(getContext(), new RecyclerItemClickListener.OnItemClickListener() {
                    @Override
                    public void onItemClick(View view, int position) {
                        final int valueThisIteration = position;
                        mRecyclerView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                            @Override
                            public void onGlobalLayout() {
                                TextView textViewDrawerTitle = (TextView) mRecyclerView.getChildAt(valueThisIteration).findViewById(R.id.tvText);
                                textViewDrawerTitle.setText("Checked");
                                mRecyclerView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                            }
                        });

                    }
                })
        );

我得到这个错误.

11-04 09:36:02.818 1629-1629/? E/AndroidRuntime: FATAL EXCEPTION: main
11-04 09:36:02.818 1629-1629/? E/AndroidRuntime: Process: com.thesis.juandirection.juandirectionfinale, PID: 1629
11-04 09:36:02.818 1629-1629/? E/AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on …