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Asynchronous API for .NET 4.5, Windows Store,

and Windows Phone 8

The AWS SDK for .NET uses the new task-based asynchronous pattern for .NET 4.5, Windows Store,

and Windows Phone 8.You can use the async and await keywords to perform and manage asynchronous

operations for all AWS products without blocking.

To learn more about the task-based asynchronous pattern, see Task-based Asynchronous Pattern (TAP)

on MSDN.

Asynchronous API for .NET 3.5

The AWS SDK for .NET supports asynchronous (async) versions of most of the method calls exposed

by the .NET client classes.The async methods enable you to call AWS services without having your code

block on the response from the service. For example, you could make a request to write data to Amazon

S3 or DynamoDB and then have your code continue to do other work while AWS processes the requests.

Syntax of Async Request Methods

There are two phases to making an asynchronous request to an AWS service.The first is to call the Begin

method for the request. This method initiates the asynchronous operation. Then, after some period of

time, you would call the corresponding End method.This method retrieves the response from the service

and also provides an opportunity to handle exceptions that might have occurred during the operation.

Note

It is not required that you call the End method. Assuming that no errors are encountered, the

asynchronous operation will complete whether or not you call End.

Begin Method Syntax

In addition to taking a request object parameter, such as PutItemRequest, the async Begin methods

take two additional parameters: a callback function, and a state object. Instead of returning a service re-

sponse object, the Begin methods return a result of type IAsyncResult. For the definition of this type,

go to the MSDN documentation.

Synchronous Method

PutItemResponse PutItem(

PutItemRequest putItemRequest

)

Asynchronous Method

IAsyncResult BeginPutItem(

GetSessionTokenRequest getSessionTokenRequest,

AsyncCallback callback,

Object state

)

AsyncCallback callback

The callback function is called when the asynchronous operation completes.When the function is called,

it receives a single parameter of type IAsyncResult. The callback function has the following signature.

Version v2.0.0

AWS SDK for .NET Developer Guide

Asynchronous API for .NET 4.5,Windows Store, and

Windows Phone 8

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Amazon AWS SDK Betriebsanweisung Seite 21