关于光标的使用真的很困惑。
我有一项工作正常的活动，代码如下：
public class AreaActivity extends ListActivity {
private TextView secondaryTitle;
private Button newArea;
private static final int ACTIVITY_CREATE=0;
private RMDbAdapter rmDbHelper;
private AlertDialog clickOptionsDialog;
private long inspectionId;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_area);
rmDbHelper = new RMDbAdapter(this);
rmDbHelper.open();
Intent i = getIntent();
inspectionId = i.getLongExtra("Intent_InspectionID", -1);
setUpViews();
setLongClick();
// Get a Cursor for the list items
Cursor listCursor = rmDbHelper.fetchAllAreasForInspection(inspectionId);
startManagingCursor(listCursor);
// set the custom list adapter
setListAdapter(new MyListAdapter(this, listCursor));
}
private void setUpViews() {
secondaryTitle = (TextView)findViewById(R.id.secondary_title);
final Cursor cursor = (Cursor) rmDbHelper.fetchInspection(inspectionId);
String inspectionRef = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex(
RMDbAdapter.INSPECTION_REF)), "Reference unknown");
String companyName = RMUtilities.notEmpty(cursor.getString(cursor.getColumnIndex(
RMDbAdapter.INSPECTION_COMPANY)), "company unknown");
cursor.close();
final String secondaryTitleText = inspectionRef + ", " + companyName;
secondaryTitle.setText(secondaryTitleText);
newArea = (Button)findViewById(R.id.new_area);
newArea.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
createArea();
}
});
}
光标从数据库中获取信息，然后检查它是否为空（使用本网站上向我推荐的单独类中的代码）并将文本设置在TextView.
但是，当我在下一个活动中使用这个确切的代码来做同样的事情时，我得到了错误：
CursorIndexOutOfBoundsException: 请求索引 0，大小为 0..
代码是一样的，所以我猜这是复制游标或不使用的问题，moveToFirst但我所做的似乎没有解决问题。