在同一项目中使用Web API 2和Forms应用程序进行错误处理-如何设置以同时处理两者？

Question

I have a project that contains both a Web API 2 service and aspx forms . But I am trying to set up error handling so I can send users to a 404 error page if they try putting in fake page in the url. Of course the Web API also needs to send 400 status message back to the users who call the web service so I am trying to keep the functionality of both in place. The main problem is I am not sure how to best set up the web.config as it not working. In my project I have both an error.aspx and error404.aspx pages.

With this in the web.config file:

<customErrors mode="RemoteOnly" defaultRedirect="~/error.aspx" redirectMode="ResponseRewrite">
  <error statusCode="404" redirect="~/error404.aspx"/>
</customErrors>

<!-- setting existingResponse="PassThrough" needed, otherwise web api 400 error messages will not return -->
    <httpErrors existingResponse="PassThrough" errorMode="Custom">
  <remove statusCode="404" subStatusCode="-1"/>
  <error statusCode="404" prefixLanguageFilePath="" path="/myApp/error404.aspx" responseMode="ExecuteURL"/>
</httpErrors>

My app will return something like the following when I put in a fake page: http://myServer/myApp/fake.aspx

Server Error in '/myApp' Application. Runtime Error Description: An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page for the first exception. The request has been terminated.

However, I can get the 404 page to show up if I change in the web.config: <httpErrors existingResponse="Replace" But making this changes causes the web API 400 status code messages not to show up when I send something like the following from my controller's get function: Return BadRequest("Your parameter is invalid") but these status messages are very important for the consumer of the service.

Any ideas how I can set up the project so I can get both errors to show up? Setting <httpErrors existingResponse="Auto" allows the Web API errors to be sent back, but not the error404.aspx for bad forms requests.

One thing I was wondering, if the Global.asax file might help as shown here or is such a process as this even possible?

Answer 1

In fact no error pages should be setup in the web.config file at instead.

I followed the technique outlined in this post: Custom error pages for non-existant directory/file Web API (not controllers)