Attribute routing with optional parameters in ASP.NET Web API

Question

I'm trying to use Web API 2 attribute routing to set up a custom API. I've got my route working such that my function gets called, but for some reason I need to pass in my first parameter for everything to work properly. The following are the URLs I want to support:

http://mysite/api/servicename/parameter1
http://mysite/api/servicename/parameter1?parameter2=value2
http://mysite/api/servicename/parameter1?parameter2=value2&parameter3=value3
http://mysite/api/servicename/parameter1?parameter2=value2&parameter3=value3&p4=v4

The last 3 URLs work but the first one says "No action was found on the controller 'controller name' that matches the request."

My controller looks like this:

public class MyServiceController : ApiController
{
    [Route("api/servicename/{parameter1}")]
    [HttpGet]
    public async Task<ReturnType> Get(string parameter1, DateTime? parameter2, string parameter3 = "", string p4 = "")
    {
        // process
    }
}

score 67 · Accepted Answer · edited Dec 29 '15 at 15:49

67

Web API requires to explicitly set optional values even for nullable types...so you can try setting the following and you should see your 1st request succeed

DateTime? parameter2 = null

edited Dec 29 '15 at 15:49

mbomb007

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answered Mar 14 '14 at 06:27

Kiran

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What did your RouteAttribute end up looking like to support the optional parameters (or what does the request URL look like if your route is simply like the original post)? – Colin Feb 26 '15 at 06:03

Attribute routing with optional parameters in ASP.NET Web API

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