WebC# (CSharp) replace.meadString – 1 examples found. These are the top rated real world C# (CSharp) examples of replace.meadString extracted from open . WebApr 16,  · Download file using HttpClient wrapper asynchronously. # httpclient # dotnet # http # csharp. HttpClient is a simple and robust wrapper to send and receive HTTP . WebThe server-side app is an replace.me Core web project, which includes a Web API controller for uploading and downloading files. The client-side app is a Console project, which .
 
 

 

Upload/Download Files using HttpClient – PureSourceCode – {dialog-heading}

 

Downloading files programmatically is a common task that most programming languages expose different APIs for. I believe it is useful to have examples to refer to for how to accomplish this in your language of choice, both synchronously and asynchronously.

This article covers how to download files with C using the classes and methods that are conveniently built into the. NET Framework. Note that you can also work with the HttpRequestMessage class directly for low-level access to HTTP requests, but I find that this approach is rarely required, especially not for simpler operations like downloading files.

Since the very first versions of the. This includes methods to download files, strings, and arbitrary binary data using byte arrays. The WebClient class also includes methods for uploading resources to web servers. First of all, make sure you have the appropriate using statement in place, as follows.

This is needed in order to use the WebClient class without requiring a fully qualified namespace. The WebClient class itself is really easy to use. The very simplest example of downloading a file is as follows. The DownloadFile method accepts a URL to download a file from and a local file path to download the file to. All of the above happens synchronously i. Unfortunately, the DownloadFile method does not provide a way of reporting progress, as it is a synchronous method.

However, there is a built-in way of asynchronously downloading a file and reporting progress with the WebClient class, as demonstrated in the example below. The above code is very similar to the synchronous example. The DownloadProgressChanged event is fired periodically as the download progresses and provides access to some useful properties such as BytesReceived and ProgressPercentage. As expected, the DownloadFileCompleted event is fired whenever the file download has completed.

As it stands, the above code will continue past the DownloadFileAsync method call while the download is in progress, since it is an asynchronous method call.

In order to download the file asynchronously using the DownloadFileAsync method and wait until the download has completed before continuing program execution, we need to dip into the world of reset events. The AutoResetEvent in the above code allows us to wait at the point where the WaitOne method is called.

When the DownloadFileCompleted event is fired, the Set method on the AutoResetEvent sends a signal that allows the code to proceed to the next statement. Note that the use of AutoResetEvent as shown above, is a neat little trick that can be applied to any other asynchronous methods you want to call and subsequently wait for completion. Although the above example works, there is a cleaner way to achieve the same result, providing you are targeting. NET Framework 4. NET Core 2. NET Standard 2.

By using the await keyword when calling the DownloadFileTaskAsync method, the code will wait until the file download has completed, while at the same time carrying out the download asynchronously and firing the progress events. Note that whatever method you use the above code within needs to be marked with the async keyword. Before attempting to use the HttpClient class, make sure you have the appropriate using statement in place, as follows. Note that even though HttpClient implements IDisposable it is recommended that you create one instance of HttpClient and reuse this throughout your program to avoid problems such as socket exhaustion.

As you can see from the above example, the code required to download a file using HttpClient is a little lower level compared to using WebClient , since we need to work with streams directly.

Nonetheless, the code is still straightforward to follow along with. Note that as per the previous example, whatever method you use the above code within needs to be marked with the async keyword. For any new development work, it is recommended that you use HttpClient. It has a number of advantages over WebClient , including more configuration options and it facilitates easier mocking and testing. However, it does have some disadvantages, such as the lack of built-in progress reporting.

In this article, I have covered the two main ways of downloading files using C and the. WebClient makes it really easy to download files, with its high-level API and it is available regardless of what. NET version you are targeting. Use HttpClient whenever you need more control and as the recommended option for new development. Yes, add me to your mailing list. This site uses Akismet to reduce spam. Learn how your comment data is processed.

Home Blog About Contact. How to download files using C 0 May 20, The options When using C there are two main options that. NET provides us with. WebClient Since the very first versions of the. Synchronous example First of all, make sure you have the appropriate using statement in place, as follows. Net; This is needed in order to use the WebClient class without requiring a fully qualified namespace.

Asynchronous example What if we want to download a file asynchronously and report progress? WriteLine “Download file completed. Additionally, two event handlers are wired up before the file download commences.

Asynchronous wait example In order to download the file asynchronously using the DownloadFileAsync method and wait until the download has completed before continuing program execution, we need to dip into the world of reset events. The example below demonstrates how to accomplish this. Async await example Although the above example works, there is a cleaner way to achieve the same result, providing you are targeting.

The example below demonstrates this approach. HttpClient Since. HttpClient offers lots of different methods and is very powerful. Summary In this article, I have covered the two main ways of downloading files using C and the. I hope you enjoyed this post!

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