[. NET] Using async & await to convert synchronous code to asynchronous programming

convert synchronous code to asynchronous programming using Async & await Step-by- step

"Bo Master" anti-bone Aberdeen "provenance" http://www.cnblogs.com/liqingwen/p/6079707.html

Order

last time, bloggers introduced the basic usage of async & await and the asynchronous control flow and some other things through asynchronous programming with Async & await.

Async solution . Do you know? The new features of Visual Studio 2012 make it easier and more intuitive to program asynchronously.

Introduction

This is explained by a common WPF program:

A text box and a button, the content of the left text box is the result of the right click button.

Add Reference

Plus the using command that the demo will use.

using System.IO; using System.Net; using System.Net.Http; using System.Threading;

First, create a synchronized WPF

1. This is the event of the right click button:

1         /// <summary>2         ///Click events3         /// </summary>4         /// <param name= "Sender" ></param>5         /// <param name= "E" ></param>6         Private voidBtnswitch_click (Objectsender, RoutedEventArgs e)7         {8             //Clear all contents of text box9 tbresult.clear ();Ten  One             //Total Statistics A sumsizes (); -}

2. I include several methods within the Sumsizes method:

①initurlinfoes: Initializes a list of URL information;

②geturlcontents: Get the content of the website;

③displayresults: Displays the results.

(1) Sumsizes method: Total Statistics.

1         /// <summary>2         ///Total Statistics3         /// </summary>4         Private voidsumsizes ()5         {6             //Load URLs7             varURLs =initurlinfoes ();8 9             //Total BytesTen             varTotalCount =0; One             foreach(varUrlinchURLs) A             { -                 //returns a byte array of the contents of a URL -                 varContents =geturlcontents (URL); the  -                 //Show Results - displayresults (URL, contents); -  +                 //Total Updates -TotalCount + =contents. Length; +             } A  atTbresult.text + = $"\ r \ n total: {totalcount}, ok! "; -}

(2) Initurlinfoes method: Initializes a list of URL information.

1         /// <summary>2         ///initializing a list of URL information3         /// </summary>4         /// <returns></returns>5         Privateilist<string>initurlinfoes ()6         {7             varURLs =Newlist<string>()8             {9                 "http://www.cnblogs.com/",Ten                 "http://www.cnblogs.com/liqingwen/", One                 "http://www.cnblogs.com/liqingwen/p/5902587.html", A                 "http://www.cnblogs.com/liqingwen/p/5922573.html" -             }; -  the             returnURLs; -}

(3) Geturlcontents method: Get URL content.

1         /// <summary>2         ///Get URL content3         /// </summary>4         /// <param name= "url" ></param>5         /// <returns></returns>6         Private byte[] Geturlcontents (stringURL)7         {8             //assuming an average download speed delay of 300 milliseconds9Thread.Sleep ( -);Ten  One             using(varms =NewMemoryStream ()) A             { -                 varreq =webrequest.create (URL); -  the                 using(varResponse =req. GetResponse ()) -                 { -                     //reads data from the specified URL -                     using(varrs =Response. GetResponseStream ()) +                     { -                         //reads a byte from the current stream and writes it to another class + Rs. CopyTo (MS); A                     } at                 } -  -                 returnMs. ToArray (); -             } -  -}

(4) DisplayResults method: Show Results

1         /// <summary>2         ///Show Results3         /// </summary>4         /// <param name= "url" ></param>5         /// <param name= "content" ></param>6         Private voidDisplayResults (stringUrlbyte[] content)7         {8             //Content Length9             varbytes =content. Length;Ten  One             //To remove http://prefix A             varReplaceurl = URL. Replace ("/ http",""); -  -             //Show theTbresult.text + = $"\ r \ n {replaceurl}: {bytes}"; -}

Test result diagram

[. NET] Using async & await to convert synchronous code to asynchronous programming