There is one thing that most client projects have in common – they request data, in some form, from a server. When developing for Windows Phone I prefer to do these requests using HttpWebRequest instead of WebClient (why – explained here by Andreas).
But this is not a post about Windows Phone, it’s about the HttpClient that is now included in .NET Framework 4.5. Even more specifically – this post is about why HttpClient is awesome and why you’ll love it.
GET according to HttpClient
This is how you do a GET.
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public async Task<JsonObject> GetAsync(string uri) { var httpClient = new HttpClient(); var response = await httpClient.GetAsync(uri); //will throw an exception if not successful response.EnsureSuccessStatusCode(); string content = await response.Content.ReadAsStringAsync(); return await Task.Run(() => JsonObject.Parse(content)); } |
That’s it folks. Thanks to the new language features of C# and HttpClient we can easily do a web request asynchronously. In this example we also do a asynchronous parse of the result using into a JsonObject.
But we actually can make it even simpler.
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public async Task<JsonObject> GetAsync(string uri) { var httpClient = new HttpClient(); var content = await httpClient.GetStringAsync(uri); return await Task.Run(() => JsonObject.Parse(content)); } |
Three lines to do an asynchronous HTTP GET and parsing (not counting the try/catch you need to wrap this method with).
POST according to HttpClient
This is how you do a POST with some string data.
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public async Task<JsonObject> PostAsync(string uri, string data) { var httpClient = new HttpClient(); response = await httpClient.PostAsync(uri, new StringContent(data)); response.EnsureSuccessStatusCode(); string content = await response.Content.ReadAsStringAsync(); return await Task.Run(() => JsonObject.Parse(content)); } |
As you can see it is very similar to GET. What you also notice is that it is extremely simple to add POST data (at least if you compare it to the trusty old HttpWebRequest).
Summary
HttpClient is actually available as a NuGet package that you can download today. But a lot of the simplicity of using HttpClient comes from the new language features of C# 5. Combine these two and you got a very simple way of requesting and posting data. If you want to read more details about HttpClient I recommend this post by Darrel Miller.
HttpClient – Learn it, Live it, Love it.
Vincent D'Souza
22 Mar 2013Great article Peter. But I have question for you. You mention about the JsonObject in you example. But I cannot find this anywhere even though I have installed JSon.Net. When I googled for it, I found this MSDN article http://msdn.microsoft.com/en-us/library/system.json.jsonobject%28v=vs.110%29.aspx which says it is part of System but even though I use Framework 4.5 I cannot find it within System namespace.
So, would you mind mentioning this in your article on how to find this JsonObject please? That would definitely help a lot of people like me who go crazy on where to find this class in what namespace and/or what are the requirements to enjoy this functionality.
Thanks,
Vincent
xcode
22 Mar 2013Vincent – Use JObject instead supported as part of Newtonsoft.Json
t@rn
10 May 2013Vincent – from the document http://msdn.microsoft.com/en-us/library/cc626400(v=vs.95).aspx It’s a part of Silverlight framework
Mike S
16 May 2013Vincent, perhaps try System.Json as namespace. See: http://msdn.microsoft.com/en-us/library/system.json.jsonobject(v=vs.110).aspx
Conde
6 Jun 2013hi
can you please complete the verbs put and delete and aggregate a simple of use. Please !!
thank!!
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Mike
24 Sep 2013Hi, if I try to use JsonObject as the return type I get errors… it only works for me if I use this code:
public static class Helper
{
public static async Task GetAsync(string uri)
{
var httpClient = new HttpClient();
var content = await httpClient.GetStringAsync(uri);
return await Task.Run(() => JsonValue.Parse(content));
}
}
Is this the same thing or is JsonValue different from JsonObject?
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qwe
13 Nov 2013It’s actually JObject, not JsonObject
Chris Marisic
5 May 2014return await Task.Run(() = JsonObject.Parse(content));
You shouldn’t do this. You should only use async await for IO bound operations. Since JsonObject.Parse is CPU bound you’re actually making it take longer and chew up more threads than needed.
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Nuri
4 Nov 2015hi Jayway :)
Code nice but some encoding issue on your code. > < etc.
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hannah
15 Mar 2017Thanks for the great article!
Just wanted to let you know that your are appearing as < and > in Chrome 56.0.2924.87
Giuz
20 Apr 2017httpClient, response and content are all disposable, and must be disposed of. Much better if you put them in 3 using statements. Calling Disose() is not oprional
Peter von Lochow Sucks That Homo Dick
27 Apr 2017well talk about a worthless shit crapola post rofl
Peter von Lochow rofl sounds like something that comes out a cows ahole
Hey Peter von Lochow rofl how long you been sticking that unit inch dick of yous up the goats ahole
Paul W Smietan
21 Nov 2018Nice examples – you may want to clean up the encoding in your source :-)