（RecyclerView）尝试在空对象引用上调用虚拟方法“void android.widget.TextView.setText（java.lang.CharSequence）”

我在设置文本时遇到空点异常

回收者视图的我的片段

public class Product_Manual_Frag extends Fragment implements View.OnClickListener {

    //Database
    DBHelper db;
    Cursor myCursor = null;
    View rootView;
    // Cursor myCursor = null;
    List<RecyclerModel> data = fill_with_data();


    Pos_Ability_Activity main_Activity;

    public Product_Manual_Frag() {
        // Required empty public constructor
    }

    @Override
    public void onClick(View v) {

    }


    private List<RecyclerModel> fill_with_data() {
        List<RecyclerModel> data=new ArrayList<>();
        data.add(new RecyclerModel("Item1","10,000","2000","$"));
        data.add(new RecyclerModel("Item1","10,000","2000","$"));
        data.add(new RecyclerModel("Item1","10,000","2000","$"));
        data.add(new RecyclerModel("Item1","10,000","2000","$"));
        return data;

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
       rootView = inflater.inflate(R.layout.fragment_poduct_manual, container, false);

        RecyclerView recycler=(RecyclerView)rootView.findViewById(R.id.my_recycler_view);
        RecyclerViewAdapter adapter=new RecyclerViewAdapter(data,getActivity());
        recycler.setLayoutManager(new LinearLayoutManager(getContext()));
        recycler.setAdapter(adapter);



        // Inflate the layout for this fragment
        return rootView;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
    }

    @Override
    public void onDetach() {
        super.onDetach();
    }
}

我的xml片段

    <?xml version="1.0" encoding="utf-8"?>
     <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@drawable/app_bg">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:scrollbars="vertical" />
</RelativeLayout>

我的行

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/relativeLayout1"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">


    <ImageView
        android:id="@+id/imgIcon"
        android:background="@drawable/cashback"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_alignParentLeft="true" />

    <TextView
        android:id="@+id/txtPName"
        android:text="Item name  sample"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@+id/imgIcon" />

    <TextView
        android:id="@+id/txtPOrgPrice"
        android:text="10,000 "
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/txtPName"
        android:layout_toRightOf="@+id/imgIcon" />

    <TextView
        android:id="@+id/lblCurSym"
        android:text="$"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/txtPOrgPrice"
        android:layout_toRightOf="@+id/imgIcon" />

    <TextView
        android:id="@+id/txtPDisPrice"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/txtPOrgPrice"
        android:layout_toRightOf="@+id/lblCurSym"
        android:paddingBottom="2dp"
        android:paddingRight="2dp"
        android:paddingTop="2dp"
        android:text="2,000 "
        android:textColor="#83410e"
        android:textSize="14sp" />

    <CheckBox
        android:id="@+id/chkBox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true" />


</RelativeLayout>

我遗漏了什么吗？请指出我所犯的错误。

检查此布局：R.layout.nav\u drawer\u row txtPname很可能为空。

请尝试以下操作：

@Override
public myViewholder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView= inflater.inflate(R.layout.nav_drawer_row, parent, false);
RecyclerViewAdapter.myViewholder holder = new RecyclerViewAdapter.myViewholder(itemView);
    holder.rl = (RelativeLayout) itemView.findViewById(R.id.relativeLayout1);
    holder .txtPname = (TextView) itemView.findViewById(R.id.txtPName);
    holder .txtorgprice = (TextView) itemView.findViewById(R.id.txtPOrgPrice);
    holder .txtdisprice = (TextView) itemView.findViewById(R.id.txtPDisPrice);
    holder .txtcursym = (TextView) itemView.findViewById(R.id.lblCurSym);
    holder .chkbx = (CheckBox) itemView.findViewById(R.id.chkBox);
return holder;
}
class myViewholder extends RecyclerView.ViewHolder {
RelativeLayout rl;
TextView txtPname, txtorgprice, txtdisprice, txtcursym;
CheckBox chkbx;

public myViewholder(View itemView) {
    super(itemView);
}
}

---

您的适配器中有R.layout.nav\u drawer\u行

此方法如下所示：

@Override
public myViewholder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.nav_drawer_row, parent, false);
    RecyclerViewAdapter.myViewholder holder = new RecyclerViewAdapter.myViewholder(view);
    return holder;
}

改为这样做

@Override
public myViewholder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.my_row_xml, parent, false);
    RecyclerViewAdapter.myViewholder holder = new RecyclerViewAdapter.myViewholder(view);
    return holder;
}

因此，如果将错误的xml引用到viewholder，则必然会得到null pointer EXECOPTION

对recyclerview进行一些研究，您将获得关于如何使用recyclerview的更多想法检查R.layout.nav\u drawer\u行是否是onCreateViewHolder中的正确布局

---

从逻辑上讲，如果TextView的实例为null，则holder中的findViewById调用返回null。一个可能的原因是试图错误地膨胀一个不同的布局，一个没有找到特定id的布局。在设置文本之前，请查看

中的定义，检查是否为null。调试器未命中BindViewHolder方法。请将调试点添加到“holder.txtPname.setTextdata.getposition.Itemname；”它没有击中..应用程序在此之前就已经关闭了。请尝试以下操作：holder.txtPname.setText+data.getposition.Itemname；清理并重建您的项目。为什么要进行检查？你能为你的答案添加一些解释，以便其他人可以从中学习吗？请将所有这些解释添加到答案中，而不是添加到评论部分

@Override
public myViewholder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.nav_drawer_row, parent, false);
    RecyclerViewAdapter.myViewholder holder = new RecyclerViewAdapter.myViewholder(view);
    return holder;
}

@Override
public myViewholder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.my_row_xml, parent, false);
    RecyclerViewAdapter.myViewholder holder = new RecyclerViewAdapter.myViewholder(view);
    return holder;
}