Question

我正在尝试获取ListView成员的数据库ID，以便我可以将其传递给新活动，但SimpleCursorAdapter的.getItemId（position）方法返回null，而不是数据库中的_id。我的理解是，它应该返回光标抓住的_id字段，但它对我来说不起作用。会喜欢一些建议

DatabaseHelper helper = new DatabaseHelper(this);
    database = helper.getWritableDatabase();
    Cursor data = database.query("myDb", fields, null, null, null, null, null);
    dataSource = new SimpleCursorAdapter(this, R.layout.row, data, fields, new int[] {R.id.idText, R.id.castName, R.id.castDescription});
    data.moveToFirst();

    final ListView view = getListView();

    view.setHeaderDividersEnabled(true);
    view.addHeaderView(getLayoutInflater().inflate(R.layout.row, null));
    setListAdapter(dataSource);


    database.close();

    view.setOnItemClickListener(new AdapterView.OnItemClickListener() {

          @Override
          public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {


            // Prepare intent
        Intent newActivity = new Intent(getApplicationContext(), ItemIdTester.class);
            newActivity.putExtra("itemId",dataSource.getItemId(position));

            // start activity
            startActivity(newActivity);
          }
        });

Answer 1

由于

添加了标头，适配器返回null

view.setHeaderDividersEnabled(true);
view.addHeaderView(getLayoutInflater().inflate(R.layout.row, null));

我也开始直接从光标获取数据。这是修复问题的完整onItemClickListener

view.setOnItemClickListener(new AdapterView.OnItemClickListener() {

          @Override
          public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {

            Cursor cursor = (Cursor) dataSource.getItem(position-1);

            Long itemId = cursor.getLong(0);  
            // Prepare intent
            Intent newActivity = new Intent(getApplicationContext(), CastrRecorder.class);
            newActivity.putExtra("itemId",itemId.toString());
            // start activity
            startActivity(newActivity);
          }
        });

dataSource.getItemId（position）返回null

1 个答案: