例如我们在Web Api项目中有个Controller
public class SomeController : ApiController
{
public HttpResponseMessage Get()
{
// 一些操作
return Request.CreateResponse(HttpStatusCode.OK, someModel);
}
}
  如果你在单元测试中直接调用 SomeController 的Get()方法,那么你将会收到一个Exception提示Request为Null。
  因此我们需要在测试代码中构造一个Request,有两种方法
  1、简单构造法
[TestMethod]
public void UnitTestMethod()
{
// 环境准备部分
YourNameSpace.Controllers.SomeController controller = new SomeController();
// 下面两个语句是构造一个简单的请求报文
controller.Request = new HttpRequestMessage();
controller.Request.SetConfiguration(new HttpConfiguration());
var result = controller.Get();
// 断言
}
  2、可控性更强的构造
[TestMethod]
public void UnitTestMethod()
{
// 环境准备部分
YourNameSpace.Controllers.SomeController controller = new SomeController();
var config = new HttpConfiguration();
var request = new HttpRequestMessage(HttpMethod.Post, "YourUrl");
var route = config.Routes.MapHttpRoute("DefaultApi", "api/{controller}/{id}");
var routeData = new HttpRouteData(route, new HttpRouteValueDictionary { { "controller", "products" } });
controller.ControllerContext = new HttpControllerContext(config, routeData, request);
controller.Request = request;
controller.Request.Properties[HttpPropertyKeys.HttpConfigurationKey] = config;
var result = controller.Get();
// 断言
}
  然后可以运行单元测试查看结果了。