withValueBackReference简介

iyangxin

ContentProviderOperation.Builder的withValueBackReference函数定义如下：

ContentProviderOperation.Builder	withValueBackReference(String key, int previousResult)Add a ContentValues back reference. 第一个参数key对应于数据库中的列名，第二个参数previousResult代表着：回引数据库批量操作中的第previousResult个数据库操作的返回值。 总的来说就是说把批量数据库操作中的第previousResult个数据库操作的返回值作为列名为key的记录的值
ContentProviderOperation.Builder	withValueBackReferences(ContentValues backReferences)Add a ContentValues of back references. 同上，只是把2个参数封装成一个参数。

示例1：
来源http://developer.android.com/reference/android/provider/ContactsContract.RawContacts.html

[Java] 纯文本查看 复制代码

ArrayList<ContentProviderOperation> ops =
          new ArrayList<ContentProviderOperation>();
 ...
 int rawContactInsertIndex = ops.size();
 ops.add(ContentProviderOperation.newInsert(RawContacts.CONTENT_URI)
          .withValue(RawContacts.ACCOUNT_TYPE, accountType)
          .withValue(RawContacts.ACCOUNT_NAME, accountName)
          .build());

 ops.add(ContentProviderOperation.newInsert(Data.CONTENT_URI)
          .withValueBackReference(Data.RAW_CONTACT_ID, rawContactInsertIndex)
          .withValue(Data.MIMETYPE, StructuredName.CONTENT_ITEM_TYPE)
          .withValue(StructuredName.DISPLAY_NAME, "Mike Sullivan")
          .build());

 getContentResolver().applyBatch(ContactsContract.AUTHORITY, ops);

Note the use of withValueBackReference(String, int) to refer to the as-yet-unknown index value of the raw contact inserted in the first operation.

结束！