查询没有记录的内容提供商？

发布于 2024-10-27 13:13:48 字数 1000 浏览 0 评论 0原文

我正在研究一种使用游标查询内容提供者的方法。删除记录后，它会调用 loadfromProvider 方法并刷新数组列表。内容提供程序通常包含记录，但是，当我删除所有记录并且查询自动运行时，它会引发异常。这是我的方法：

private void loadFromProvider() {

    // Clear the existing array list

    EQlist.clear();

      ContentResolver cr = getContentResolver();

      // Return all the saved records
      Cursor c = cr.query(EQProvider.CONTENT_URI, null, null, null, null);

      if (c.moveToFirst()) {
        do { 

          String details = c.getString(EQProvider.DETAILS_COLUMN);
          String linkString = c.getString(EQProvider.LINK_COLUMN);

          EQli q = new EQli(details, linkString);
          addEQToArray(q);
        } while(c.moveToNext());
      }
      c.close();
      }

当我在内容提供程序中没有记录的情况下运行此方法时，它会抛出以下内容：

java.lang.IndexOutOfBoundsException：无效索引 1，大小为 1 在 java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:257)

我认为这是由于光标试图解析空值。我试图找出一种方法，如果光标没有返回任何记录，它会绕过代码的其余部分并且不会发生任何事情。

任何帮助将不胜感激。谢谢

原文

I am working on a method that queries a content provider using a cursor. After I delete a record, it calls the loadfromProvider method and refreshes the arraylist. The content provider normally has records in it however, when I delete all the records and the query runs automatically it throws exceptions. Here is my method:

private void loadFromProvider() {

    // Clear the existing array list

    EQlist.clear();

      ContentResolver cr = getContentResolver();

      // Return all the saved records
      Cursor c = cr.query(EQProvider.CONTENT_URI, null, null, null, null);

      if (c.moveToFirst()) {
        do { 

          String details = c.getString(EQProvider.DETAILS_COLUMN);
          String linkString = c.getString(EQProvider.LINK_COLUMN);

          EQli q = new EQli(details, linkString);
          addEQToArray(q);
        } while(c.moveToNext());
      }
      c.close();
      }

When I run this with no records in the content provider it throws the following:

java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:257)

I think this is due to the cursor trying to parse a null value. I am trying to figure out a way that if the cursor does not come back with any records, it bypasses the rest of the code and does nothing happens.

Any help would be appreciated. Thanks

分享到QQ

分享到微博