如何为webapi配置此路由？

Question

I have a controller to GET a resource(say, Employee), which has two properties (say, CategoryId and DepartmentId). I need to configure the routes to support the following URLs:

~/api/employees/1234 [to get the employee with employeeId=1234]
~/api/employees [to get all the employees]
~/api/employees?departmentid=1 [to get all the employees with departmentId=1]

and the controller code looks like this:

public IEnumerable<Employee> Get()
{
    ....
}

public IEnumerable<Employee> Get(int employeeId, int departmentId = -1, int categoryId = -1)
{
    .....
}

How to configure routes for this controller?

Thanks

Answer 1

for any querystyring parameter, there's nothin to do on the routing side: just have the controller method parmater matching with the qs parameter name(case insensitive.)

If instead your method parameter refers to a uri segment, method paramenter name has to match with route parameter/segment between curly brackets

routes.MapHttpRoute(
    name: "API Default",
    routeTemplate: "/api/{controller}/{employeeId}",
    defaults: new { id = RouteParameter.Optional }
);

that means you need a controller with following method

public class EmployeesController : ApiController
{
public IEnumerable<Employee> Get(int employeeId){...} 
}

keep in mind that, unless you use action, on your controller you can only one method per http verb.
In other word your sample having 2 method for the verb get won't work unless you use explicit action for both of them.

Answer 2

Have you looked at using Attribute routing? We use Attribute routing extensively now, to the point that we have completely got rid of the default /controller/action type routes that we had with MapHttpRoute.

Instead we decorate our controllers as follows. Firstly we create a route prefix for the controller so that we know what the base route is that we require

/// <summary>   A controller for handling products. </summary>
[RoutePrefix("api/purchasing/locations/{locationid}/products")]
public class ProductsController : PurchasingController
{

Then for each action in the controller we decorate it as follows:

    [Route("", Name = "GetAllProducts")]
    public IHttpActionResult GetAllProducts(int locationid, ODataQueryOptions<FourthPurchasingAPI.Models.Product> queryOptions)
    {
        IList<Product> products = this.GetProducts(locationid);

and

    [Route("{productid}", Name = "GetProductById")]
    public IHttpActionResult GetProduct(int locationid, string productid)
    {
        Product product = this.GetProductByID(locationid, productid);

so a call to api/purchasing/locations/1/products/ will resolve to the route named "GetAllProducts" and a call to api/purchasing/locations/1/products/1 will resolve to the route named "GetProductById"

You could then create another GetProduct action in your controller with the same signature, just set the attribute route appropriately, eg

    [Route("/department/{departmentId}", Name = "GetAllProductsForDepartment")]
    public IHttpActionResult GetAllProductsWithDeptId(int locationid, int departmentId)
    {
        IList<Product> products = this.GetProducts(locationid, departmentId);

Now a call to api/purchasing/locations/1/products/department/1234 will resolve to the route named "GetAllProductsForDepartment"

I know that this example is using Web Api 2, but look at this link for Attribute Routing in Web Api. It should be exactly the same instead you will be returning something other than an IHttpActionResult.