Android 按光标在列表视图中显示数据

我写了一个程序，可以通过游标在listview中显示存储在数据库中的数据。但在运行时，它会强制关闭。我读logcat，但我不明白这是什么错误。我给出了代码和logcat。请帮助我

当前购物车代码：

public class current_cart extends ListActivity {

    private ListView mainListView = null;
    CustomSqlCursorAdapter adapter = null;
    private SqlHelper dbHelper = null;
    private Cursor currentCursor = null;

    private ListView listView = null;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.current_cart);

        if (this.dbHelper == null) {
            this.dbHelper = new SqlHelper(this);

        }

        listView = getListView();
        listView.setItemsCanFocus(false);
        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
        //listView.setClickable(true);

        Button btnClear = (Button) findViewById(R.id.btnClear);
        btnClear.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                Toast.makeText(getApplicationContext(),
                        " You clicked Clear button", Toast.LENGTH_SHORT).show();
              //  ClearDBSelections();
            }
        });

        new SelectDataTask().execute();

        this.mainListView = getListView();

        mainListView.setCacheColorHint(0);

    }

    @Override
    protected void onRestart() {
        super.onRestart();
        new SelectDataTask().execute();
    }

    @Override
    protected void onPause() {

        super.onPause();
        this.dbHelper.close();
    }

  //  protected void ClearDBSelections() {

      //  this.adapter.ClearSelections();

  //  }

    private class SelectDataTask extends AsyncTask<Void, Void, String> {

        protected String doInBackground(Void... params) {

            try {

                current_cart.this.dbHelper.createDatabase(dbHelper.dbSqlite);
                current_cart.this.dbHelper.openDataBase();

                current_cart.this.currentCursor = current_cart.this.dbHelper
                        .getCursor();

            } 
            catch (SQLException sqle) 
            {

                throw sqle;

            }
            return null;
        }

        // can use UI thread here
        protected void onPostExecute(final String result) {

            startManagingCursor(current_cart.this.currentCursor);
            int[] listFields = new int[] { R.id.txtTitle,R.id.txtprice };
            String[] dbColumns = new String[] { SqlHelper.COLUMN_TITLE,SqlHelper.COLUMN_NAME_DESC };

            current_cart.this.adapter = new CustomSqlCursorAdapter(
                    current_cart.this, R.layout.single_item,
                    current_cart.this.currentCursor, dbColumns, listFields,
                    current_cart.this.dbHelper);
            setListAdapter(current_cart.this.adapter);

        }
    }

}

SqlHelper代码：

    public class SqlHelper extends SQLiteOpenHelper {
        private static final String DATABASE_PATH = "/data/data/com.example.bb/databases/";

        public static final String DATABASE_NAME = "ll";

        public static final String TABLE_NAME = "w";
        public static final int ToDoItems_VERSION = 1;

       // public static final String COLUMN_ID = "_id";             
        public static final String COLUMN_TITLE = "Good_Name";         
       public static final String COLUMN_NAME_DESC = "Good_UnitPrice";


        public SQLiteDatabase dbSqlite;
        private Context mContext;

        public SqlHelper(Context context) {
            super(context, DATABASE_NAME, null, 1);
            mContext = context;
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            createDB(db);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w("SqlHelper", "Upgrading database from version " + oldVersion
                    + " to " + newVersion + ", which will destroy all old data");

            db.execSQL("DROP TABLE IF EXISTS w;");

            createDB(db);
        }

        public void createDatabase(SQLiteDatabase db) {
            createDB(db);
        }

        private void createDB(SQLiteDatabase db) {
            if (db == null) {
                db = mContext.openOrCreateDatabase(DATABASE_NAME, 0, null);
            }

            db.execSQL("CREATE TABLE IF NOT EXISTS w (Cart_ID INTEGER, Good_Name VARCHAR(50),Good_UnitPrice INTEGER (10),Quantity INTEGER);");
            db.setVersion(ToDoItems_VERSION);


        }

        public void openDataBase() throws SQLException {
            String myPath = DATABASE_PATH + DATABASE_NAME;

            dbSqlite = SQLiteDatabase.openDatabase(myPath, null,
                    SQLiteDatabase.OPEN_READWRITE);
        }

        @Override
        public synchronized void close() {
            if (dbSqlite != null)
                dbSqlite.close();

            super.close();
        }

        public Cursor getCursor() {
            SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();

            queryBuilder.setTables(TABLE_NAME);

            String[] asColumnsToReturn = new String[] {COLUMN_TITLE,COLUMN_NAME_DESC};

            Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
                    null, null, null, null);

            return mCursor;
        }

       // public void clearSelections() {
         //   ContentValues values = new ContentValues();
          //  values.put(COLUMN_SELECTED, 0);
          //  this.dbSqlite.update(SqlHelper.TABLE_NAME, values, null, null);
       // }
    }

我的日志：

12-19 14:36:02.999: E/AndroidRuntime(436): FATAL EXCEPTION: main
12-19 14:36:02.999: E/AndroidRuntime(436): java.lang.IllegalArgumentException: column '_id' does not exist
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:297)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.CursorAdapter.init(CursorAdapter.java:169)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.CursorAdapter.<init>(CursorAdapter.java:117)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.ResourceCursorAdapter.<init>(ResourceCursorAdapter.java:52)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.SimpleCursorAdapter.<init>(SimpleCursorAdapter.java:78)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.example.nfc.CustomSqlCursorAdapter.<init>(CustomSqlCursorAdapter.java:28)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.example.nfc.current_cart$SelectDataTask.onPostExecute(current_cart.java:110)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.example.nfc.current_cart$SelectDataTask.onPostExecute(current_cart.java:1)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.AsyncTask.finish(AsyncTask.java:590)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.AsyncTask.access$600(AsyncTask.java:149)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:603)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.Handler.dispatchMessage(Handler.java:99)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.Looper.loop(Looper.java:126)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.app.ActivityThread.main(ActivityThread.java:3997)
12-19 14:36:02.999: E/AndroidRuntime(436):  at java.lang.reflect.Method.invokeNative(Native Method)
12-19 14:36:02.999: E/AndroidRuntime(436):  at java.lang.reflect.Method.invoke(Method.java:491)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
12-19 14:36:02.999: E/AndroidRuntime(436):  at dalvik.system.NativeStart.main(Native Method)

12-1914:36:02.999:E/AndroidRuntime（436）：致命异常：main
12-19 14:36:02.999:E/AndroidRuntime（436）：java.lang.IllegalArgumentException:列“\u id”不存在
12-1914:36:02.999:E/AndroidRuntime（436）：位于android.database.AbstractCursor.getColumnIndexOrThrow（AbstractCursor.java:297）
12-1914:36:02.999:E/AndroidRuntime（436）：位于android.widget.CursorAdapter.init（CursorAdapter.java:169）
12-1914:36:02.999:E/AndroidRuntime（436）：在android.widget.CursorAdapter.（CursorAdapter.java:117）
12-1914:36:02.999:E/AndroidRuntime（436）：在android.widget.ResourceCursorAdapter.（ResourceCursorAdapter.java:52）
12-1914:36:02.999:E/AndroidRuntime（436）：在android.widget.SimpleCursorAdapter。（SimpleCursorAdapter.java:78）
12-1914:36:02.999:E/AndroidRuntime（436）：在com.example.nfc.CustomSqlCursorAdapter。（CustomSqlCursorAdapter.java:28）
12-19 14:36:02.999:E/AndroidRuntime（436）：在com.example.nfc.current\u cart$SelectDataTask.onPostExecute（current\u cart.java:110）
12-19 14:36:02.999:E/AndroidRuntime（436）：在com.example.nfc.current\u cart$SelectDataTask.onPostExecute（current\u cart.java:1）
12-1914:36:02.999:E/AndroidRuntime（436）：在android.os.AsyncTask.finish（AsyncTask.java:590）
12-19 14:36:02.999:E/AndroidRuntime（436）：在android.os.AsyncTask.access$600（AsyncTask.java:149）
12-19 14:36:02.999:E/AndroidRuntime（436）：位于android.os.AsyncTask$InternalHandler.handleMessage（AsyncTask.java:603）
12-1914:36:02.999:E/AndroidRuntime（436）：在android.os.Handler.dispatchMessage（Handler.java:99）上
12-1914:36:02.999:E/AndroidRuntime（436）：在android.os.Looper.loop（Looper.java:126）上
12-1914:36:02.999:E/AndroidRuntime（436）：位于android.app.ActivityThread.main（ActivityThread.java:3997）
12-19 14:36:02.999:E/AndroidRuntime（436）：位于java.lang.reflect.Method.Invokenactive（本机方法）
12-1914:36:02.999:E/AndroidRuntime（436）：位于java.lang.reflect.Method.invoke（Method.java:491）
12-19 14:36:02.999:E/AndroidRuntime（436）：在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run（ZygoteInit.java:841）
12-1914:36:02.999:E/AndroidRuntime（436）：在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:599）
12-1914:36:02.999:E/AndroidRuntime（436）：在dalvik.system.NativeStart.main（本机方法）

光标适配器要求您给它的光标包含

\u id

列，如文档中所述：

游标必须包含名为“\u id”的列，否则此类将无法工作

---

您需要将这样一列添加到表中。所有提到id的方法（onItemSelected、getItemId等）中都使用

id

。

游标适配器要求您提供的游标包含

\u id

列，如文档中所述：

游标必须包含名为“\u id”的列，否则此类将无法工作

您需要将这样一列添加到表中。所有提到id的方法中都使用了

id

（onItemSelected，getItemId，…）

您应该在SimpleCrsorAdapter的列选择列表中包含列“\u id”

您应该在SimpleCrsorAdapter的列选择列表中包含列“\u id”

12-19 14:36:02.999: E/AndroidRuntime(436): FATAL EXCEPTION: main
12-19 14:36:02.999: E/AndroidRuntime(436): java.lang.IllegalArgumentException: column '_id' does not exist
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:297)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.CursorAdapter.init(CursorAdapter.java:169)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.CursorAdapter.<init>(CursorAdapter.java:117)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.ResourceCursorAdapter.<init>(ResourceCursorAdapter.java:52)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.widget.SimpleCursorAdapter.<init>(SimpleCursorAdapter.java:78)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.example.nfc.CustomSqlCursorAdapter.<init>(CustomSqlCursorAdapter.java:28)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.example.nfc.current_cart$SelectDataTask.onPostExecute(current_cart.java:110)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.example.nfc.current_cart$SelectDataTask.onPostExecute(current_cart.java:1)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.AsyncTask.finish(AsyncTask.java:590)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.AsyncTask.access$600(AsyncTask.java:149)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:603)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.Handler.dispatchMessage(Handler.java:99)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.os.Looper.loop(Looper.java:126)
12-19 14:36:02.999: E/AndroidRuntime(436):  at android.app.ActivityThread.main(ActivityThread.java:3997)
12-19 14:36:02.999: E/AndroidRuntime(436):  at java.lang.reflect.Method.invokeNative(Native Method)
12-19 14:36:02.999: E/AndroidRuntime(436):  at java.lang.reflect.Method.invoke(Method.java:491)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
12-19 14:36:02.999: E/AndroidRuntime(436):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
12-19 14:36:02.999: E/AndroidRuntime(436):  at dalvik.system.NativeStart.main(Native Method)