Question

我需要执行大批操作。为了避免阻塞，我需要在执行此批处理时多次开始并提交数据库事务。关于ContentProviderOperation.withYieldAllowed()，我已经阅读了这个article。这完全适合我的情况。

我不明白的是：如果ContentProvider.applyBatch()方法不处理事务，android应该如何提交事务？正如文档（API 23）声明获取事务行为一样，ContentProvider必须覆盖该方法。

/**
 * Override this to handle requests to perform a batch of operations, or the
 * default implementation will iterate over the operations and call
 * {@link ContentProviderOperation#apply} on each of them.
 * If all calls to {@link ContentProviderOperation#apply} succeed
 * then a {@link ContentProviderResult} array with as many
 * elements as there were operations will be returned.  If any of the calls
 * fail, it is up to the implementation how many of the others take effect.
 * This method can be called from multiple threads, as described in
 * <a href="{@docRoot}guide/topics/fundamentals/processes-and-threads.html#Threads">Processes
 * and Threads</a>.
 *
 * @param operations the operations to apply
 * @return the results of the applications
 * @throws OperationApplicationException thrown if any operation fails.
 * @see ContentProviderOperation#apply
 */
public @NonNull ContentProviderResult[] applyBatch(

所以这意味着我必须检查操作是否允许在我的applyBatch()实现中自己产生并提交事务？这没有多大意义，我错过了什么？

Answer 1

请仔细阅读，

每当您使用ContentProviderOperation并且必须插入，更新或删除许多记录时，使用YieldAllowed（）的方法都会派上用场。

嵌套类ContentproviderOperation.Builder的withYieldAllowed（）方法处理此问题。这个方法所做的事情没有在类本身上记录。

Answer 2

按照以下代码

ArrayList（）ops = new

的ArrayList（）;

ops.add（ContentProviderOperation。 newInsert（RawContacts.CONTENT_URI）

   .withValue(RawContacts.ACCOUNT_TYPE, someAccountType)

.withValue（RawContacts.ACCOUNT_NAME，someAccountName） .build（））;

ContentProviderOperation.withYieldAllowed（）它甚至可以工作吗？

2 个答案: