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 4 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

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