Web api 2 completes successfully but returns server error 500 - asp.net-web-api2

Question

I have created a controller using web api 2 in c#.
My controller method is a post and successfully completes, returning a 201
But when the client receives the response, a 500 internal server error is returned.
Can anyone advise why this is happening?
I thought that once a controller was returning a value, the request was complete, this is obviously not the case.
[HttpPost]
[Route("PostProperty/{agentId}")]
public async Task<IActionResult> PostProperty(int agentId, [FromBody]CreatePropertyRequestDto value)
{
string result = await _mediator.Send(new NewPropertyRequest() { NewProperty = value, AgentId = agentId });
var c = CreatedAtRoute("getproperties", new { agentId, propertyIds = result }, result);
return c;
}
If I look in the output window I can see a 500 is being thrown, but I still don't know where or why. Please help
Application Insights Telemetry (unconfigured): {
"name": "Microsoft.ApplicationInsights.Dev.Request",
"time": "2018-08-13T20:51:39.9717971Z",
"tags": {
"ai.operation.name": "POST Properties/PostProperty [agentId]",
"ai.cloud.roleInstance": "DESKTOP-DM70VVS",
"ai.location.ip": "127.0.0.1",
"ai.application.ver": "1.0.0.0",
"ai.operation.id": "4d86444a-4e214be6ea456695",
"ai.internal.nodeName": "DESKTOP-DM70VVS",
"ai.internal.sdkVersion": "aspnet5c:2.1.1"
},
"data": {
"baseType": "RequestData",
"baseData": {
"ver": 2,
"id": "|4d86444a-4e214be6ea456695.",
"name": "POST Properties/PostProperty [agentId]",
"duration": "00:00:02.7187869",
"success": false,
"responseCode": "500",
"url": "http://localhost:63103/api/properties/PostProperty/1",
"properties": {
"httpMethod": "POST",
"AspNetCoreEnvironment": "Development",
"DeveloperMode": "true"
}
}
}
}
EDIT:
If I return an OK(result) a 200 is returned. So I can now confirm CreatedAtRoute() is the culprit. I have enabled app.UseDeveloperExceptionPage(); in Startup.cs and the showed me a helpful message
InvalidOperationException: No route matches the supplied values.
Reading this thread I can see the I must match the parameters of the action I am saying the item was created at.
updated post action
[HttpPost]
[Route("PostProperty/{agentId}")]
public async Task<IActionResult> PostProperty(int agentId, [FromBody]CreatePropertyRequestDto value)
{
string result = await _mediator.Send(new NewPropertyRequest() { NewProperty = value, AgentId = agentId });
return CreatedAtRoute($"GetProperty", new { agentId = agentId, propertyId = result });
}
action the above is referencing
[HttpGet]
[Route("GetProperty/{agentId}/{propertyId}")]
public async Task<IActionResult> GetProperty(int agentId, string propertyId)
{
if (agentId <= 0 || propertyId == null)
{
return BadRequest("agentId or propertyId was invalid. agentId must be a valid id and propertyId cannot be null");
}
IEnumerable<PropertyDto> properties = await GetPropertiesRequest(agentId, new List<string>(){ propertyId });
PropertyDto property = properties.FirstOrDefault();
if (property == null)
{
return NotFound();
}
return Ok(property);
}
even with the update to my post action I still get
InvalidOperationException: No route matches the supplied values.
below also returns the same exception
CreatedAtRoute(routeName: "GetProperty", routeValues: new { agentId = agentId, propertyId = result }, value: result);

Answer 1

I resolved my Issue by using CreatedAtAction(). In this scenario it is more suited that CreatedAtRoute as it is in the same controller. For a more detailed explanation of the differences read this thread
CreatedAtAction($"GetProperty", new { agentId = agentId, propertyId = result }, result);