title: optional parameters in web api 2 asp.net core not working
body: <p>I have a function like below </p>
  
  <pre><code>public CaseController{
  
  [HttpGet(GetAll/{parameter1:maxlength(50)?}/{parameter2:maxlength(50)?}/{parameter3:maxlength(50)?})
  public IEnumerable&lt;CaseDomainModel&gt; GetAll(string parameter1 = null,string parameter2 = null,string parameter3 = null)
  {
     // Code Goes here 
  }
  }
  </code></pre>
  
  <p>The api call generated goes like this </p>
  
  <p>api/case/GetAll/value1
  or 
  api/case/GetAll//value2
  or 
  or 
  api/case/GetAll///value3</p>
  
  <p>which ever value is passed from the front end to this particular api method the value is getting passed to parameter1. </p>
  
  <p>I searched SO and tried to follow <a href="https://stackoverflow.com/questions/22778640/optional-parameters-in-web-api-attribute-routing">Optional Parameters in Web Api Attribute Routing</a> but unable to find a resolution. </p>
  
  <p>My project is Angular 2 front end + webapi2 with asp.net core as a service layer. </p>
  
  <p>Could you please let me know how to make webapi2 understand my optional parameters</p>