Question

我试图通过recyclerview显示我的sqlite数据，但它给了我这个错误：

无法从CursorWindow读取第0行第9行。在从中访问数据之前，请确保Cursor已正确初始化。

CursorWindow有6行，9列。

我检查了表格列但我找不到问题！请帮忙!!

我的代码：

public class LinesC {
    private String BackgroundColor;
    private int id;
    private String City_ID;
    private int FirstStationNumber;
    private int Line_ID;
    private int LastSTationNumber;
    private int LineNumber;
    private int Status;
    private String TextColor;
    private String Title;

    public LinesC(String backgroundColor, int id, String city_ID, int firstStationNumber, int line_ID, int lastSTationNumber, int lineNumber, int status, String textColor, String title) {

        BackgroundColor = backgroundColor;
        this.id = id;
        City_ID = city_ID;
        FirstStationNumber = firstStationNumber;
        Line_ID = line_ID;
        LastSTationNumber = lastSTationNumber;
        LineNumber = lineNumber;
        Status = status;
        TextColor = textColor;
        Title = title;
    }


    public String getBackgroundColor() {
        return BackgroundColor;
    }

    public int getId() {
        return id;
    }

    public String getCity_ID() {
        return City_ID;
    }

    public int getFirstStationNumber() {
        return FirstStationNumber;
    }

    public int getLine_ID() {
        return Line_ID;
    }

    public int getLastSTationNumber() {
        return LastSTationNumber;
    }

    public int getLineNumber() {
        return LineNumber;
    }

    public int getStatus() {
        return Status;
    }

    public String getTextColor() {
        return TextColor;
    }

    public String getTitle() {
        return Title;
    }
}

我的适配器：

public class LinesAdapter extends RecyclerView.Adapter <LinesAdapter.RecyclerViewHolder> {
    SharedPreferences shared;
    SharedPreferences.Editor editor;
    ArrayList<LinesC> arrayList = new ArrayList<>();
    Context context;

    public LinesAdapter(ArrayList<LinesC> arrayList, Context context) {
        this.arrayList = arrayList;
        this.context = context;
    }

    public LinesAdapter(ArrayList<LinesC> arrayList) {
        this.arrayList = arrayList;
    }

    @Override
    public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.model_lines,parent,false);
        RecyclerViewHolder recyclerViewHolder = new RecyclerViewHolder(view);
        context = parent.getContext();
        return recyclerViewHolder;
    }


    @Override
    public void onBindViewHolder(final RecyclerViewHolder holder, int position) {
        final LinesC linesC = arrayList.get(position);
     holder.title.setText(String.valueOf(arrayList.get(position).getId()));


    }

    @Override
    public int getItemCount() {
        return arrayList.size();
    }

    public class RecyclerViewHolder extends RecyclerView.ViewHolder
    {
        TextView title;
        LinearLayout linearLayout;
        RecyclerViewHolder(View view)
        {
            super(view);
            linearLayout = (LinearLayout) itemView.findViewById(R.id.click_layout);
            title = (TextView) itemView.findViewById(R.id.title);
        }
    }

}

我的三种DBHelper类方法：

  // Create Table of Lines
    public static final String CREATE_LINES_TABLE = "create table "+ LinesContract.LinesEntry.TABLE_NAME+
            " ("+LinesContract.LinesEntry.BACKGROUND_COLOR+" text,"+LinesContract.LinesEntry.CITY_ID+" int,"+
            LinesContract.LinesEntry.FIRSTSTATIONNUMBER+" int,"+LinesContract.LinesEntry.LINE_ID+" int,"+
            LinesContract.LinesEntry.LASTSTATIONNUMBER+" int,"+LinesContract.LinesEntry.LINENUMBER+" int,"+
            LinesContract.LinesEntry.STATUS+" int,"+ LinesContract.LinesEntry.TEXTCOLOR+" text," +
            LinesContract.LinesEntry.TITLE+" text);";


  public void putLineInformation(String backgroundColor, String city_ID, int firstStationNumber, int line_ID, int lastSTationNumber, int lineNumber, int status, String textColor, String title,SQLiteDatabase sqLiteDatabase)
    {
        ContentValues contentLineValues = new ContentValues();
        contentLineValues.put(LinesContract.LinesEntry.BACKGROUND_COLOR,backgroundColor);
        contentLineValues.put(LinesContract.LinesEntry.CITY_ID,city_ID);
        contentLineValues.put(LinesContract.LinesEntry.FIRSTSTATIONNUMBER,firstStationNumber);
        contentLineValues.put(LinesContract.LinesEntry.LINE_ID,line_ID);
        contentLineValues.put(LinesContract.LinesEntry.LASTSTATIONNUMBER,lastSTationNumber);
        contentLineValues.put(LinesContract.LinesEntry.LINENUMBER,lineNumber);
        contentLineValues.put(LinesContract.LinesEntry.STATUS,status);
        contentLineValues.put(LinesContract.LinesEntry.TEXTCOLOR,textColor);
        contentLineValues.put(LinesContract.LinesEntry.TITLE,title);
        long ll = sqLiteDatabase.insert(LinesContract.LinesEntry.TABLE_NAME,null,contentLineValues);
        Log.d("Database Operations","****** One Row Inserted ******** "+contentLineValues);
    }



public Cursor getLineInformation(SQLiteDatabase sqLiteDatabaseLine)
{
    String [] projectionLine = {LinesContract.LinesEntry.BACKGROUND_COLOR, LinesContract.LinesEntry.CITY_ID, LinesContract.LinesEntry.FIRSTSTATIONNUMBER,
            LinesContract.LinesEntry.LINE_ID, LinesContract.LinesEntry.LASTSTATIONNUMBER,
            LinesContract.LinesEntry.LINENUMBER, LinesContract.LinesEntry.STATUS,
            LinesContract.LinesEntry.TEXTCOLOR, LinesContract.LinesEntry.TITLE
    };
    Cursor lineCursor = sqLiteDatabaseLine.query(LinesContract.LinesEntry.TABLE_NAME,projectionLine,null,null,null,null,null);
    return lineCursor;
}

我的AsyncTask：

 String json_url = "http://192.168.1.3/MetroRun/MRS.svc/GetLines/d5d23f68-e760-4561-b96c-d35cc3928d42/1/0";
            URL url = new URL(json_url);
            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
            InputStream inputStream = httpURLConnection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            StringBuilder stringBuilder = new StringBuilder();
            String line;
            while((line=bufferedReader.readLine())!=null)
            {
                stringBuilder.append(line+"\n");
                Thread.sleep(5000);
            }
            httpURLConnection.disconnect();
            String json_data = stringBuilder.toString().trim();
            JSONArray jsonarray = new JSONArray(json_data);
            DBHelper dbHelper = new DBHelper(ctx);
            SQLiteDatabase sqLiteDatabase = dbHelper.getWritableDatabase();
            int count = 0;
            while(count<jsonarray.length())
            {
                JSONObject o = jsonarray.getJSONObject(count);
                count++;
                dbHelper.putLineInformation(o.getString("BackgroundColor"),o.getString("CityId"),
                        o.getInt("FirstStationNumber"),o.getInt("Id"),o.getInt("LastStationNumber")
                        ,o.getInt("LineNumber"),o.getInt("Status"),o.getString("TextColor"),o.getString("Title"),sqLiteDatabase);
            }
            dbHelper.close();

我的片段：

public class Lines_fragment extends Fragment{
    private RecyclerView recyclerView;
    private RecyclerView.Adapter adapter;
    public Context context;
    ArrayList<LinesC> arrayList = new ArrayList<>();
    public Lines_fragment() {
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v =  inflater.inflate(R.layout.fragment_lines_fragment, container, false);

        recyclerView = (RecyclerView) v.findViewById(R.id.recyclerview);
        recyclerView.setLayoutManager(new LinearLayoutManager(context));
        recyclerView.setHasFixedSize(true);

        adapter = new LinesAdapter(arrayList,getActivity());
        DBHelper dbHelper = new DBHelper(getActivity());
        SQLiteDatabase sqLiteDatabaseLine = dbHelper.getReadableDatabase();
        Cursor cursor = dbHelper.getLineInformation(sqLiteDatabaseLine);
        while(cursor.moveToNext())
        {
            LinesC linesC = new LinesC(cursor.getString(0), cursor.getInt(1), cursor.getString(2), cursor.getInt(3),cursor.getInt(4),cursor.getInt(5),cursor.getInt(6),cursor.getInt(7),cursor.getString(8),cursor.getString(9));
            arrayList.add(linesC);
            adapter = new LinesAdapter(arrayList,getActivity());
        }
        dbHelper.close();
        adapter = new LinesAdapter(arrayList);
        recyclerView.setAdapter(adapter);
        return v;
    }
}

Answer 1

getLineInformation()正在检索9列：

String [] projectionLine = {LinesContract.LinesEntry.BACKGROUND_COLOR, LinesContract.LinesEntry.CITY_ID, LinesContract.LinesEntry.FIRSTSTATIONNUMBER,
        LinesContract.LinesEntry.LINE_ID, LinesContract.LinesEntry.LASTSTATIONNUMBER,
        LinesContract.LinesEntry.LINENUMBER, LinesContract.LinesEntry.STATUS,
        LinesContract.LinesEntry.TEXTCOLOR, LinesContract.LinesEntry.TITLE
};

onCreateView()正在尝试阅读10列：

        LinesC linesC = new LinesC(cursor.getString(0), cursor.getInt(1), cursor.getString(2), cursor.getInt(3),cursor.getInt(4),cursor.getInt(5),cursor.getInt(6),cursor.getInt(7),cursor.getString(8),cursor.getString(9));

您的LinesC逻辑需要与getLineInformation()逻辑同步。

从CursorWindow读取时出错

1 个答案: