Where is HttpContent.ReadAsAsync?

问题

I see in tons of examples on the web using the new HttpClient object (as part of the new Web API) that there should be HttpContent.ReadAsAsync<T> method. However, MSDN doesn\'t mention this method, nor does IntelliSense find it.

Where did it go, and how do I work around it?

回答1:

It looks like it is an extension method (in System.Net.Http.Formatting):

HttpContentExtensions Class

Update:

PM> install-package Microsoft.AspNet.WebApi.Client

According to the System.Net.Http.Formatting NuGet package page, the System.Net.Http.Formatting package is now legacy and can instead be found in the Microsoft.AspNet.WebApi.Client package available on NuGet here.

回答2:

I have the same problem, so I simply get JSON string and deserialize to my class:

HttpResponseMessage response = await client.GetAsync("Products");
//get data as Json string 
string data = await response.Content.ReadAsStringAsync();
//use JavaScriptSerializer from System.Web.Script.Serialization
JavaScriptSerializer JSserializer = new JavaScriptSerializer();
//deserialize to your class
products = JSserializer.Deserialize<List<Product>>(data);

回答3:

If you are already using Newtonsoft.Json and don't want to install Microsoft.AspNet.WebApi.Client:

 var myInstance = JsonConvert.DeserializeObject<MyClass>(
   await response.Content.ReadAsStringAsync());

回答4:

You can write extention method:

public static async Task<Tout> ReadAsAsync<Tout>(this System.Net.Http.HttpContent content) {
    return Newtonsoft.Json.JsonConvert.DeserializeObject<Tout>(await content.ReadAsStringAsync());
}

回答5:

Just right click in your project go Manage NuGet Packages search for Microsoft.AspNet.WebApi.Client install it and you will have access to the extension method.

回答6:

Having hit this one a few times and followed a bunch of suggestions, if you don't find it available after installing the NuGet Microsoft.AspNet.WebApi.Client manually add a reference from the packages folder in the solution to:

\Microsoft.AspNet.WebApi.Client.5.2.6\lib\net45\System.Net.Http.Formatting.dll

And don't get into the trap of adding older references to the System.Net.Http.Formatting.dll NuGet

来源：https://stackoverflow.com/questions/10399324/where-is-httpcontent-readasasync