Need a complete sample to handle unhandled exceptions using "ExceptionHandler" in ASP.NET Web Api?

asp.net-web-api, c#, exception

Solution

In your WebApi config your need to add the line:

config.Services.Replace(typeof (IExceptionHandler), new OopsExceptionHandler());

Also make sure you have created the base ExceptionHandler class that implements IExceptionHandler:

public class ExceptionHandler : IExceptionHandler
{
    public virtual Task HandleAsync(ExceptionHandlerContext context, 
                                    CancellationToken cancellationToken)
    {
        if (!ShouldHandle(context))
        {
            return Task.FromResult(0);
        }

        return HandleAsyncCore(context, cancellationToken);
    }

    public virtual Task HandleAsyncCore(ExceptionHandlerContext context, 
                                       CancellationToken cancellationToken)
    {
        HandleCore(context);
        return Task.FromResult(0);
    }

    public virtual void HandleCore(ExceptionHandlerContext context)
    {
    }

    public virtual bool ShouldHandle(ExceptionHandlerContext context)
    {
        return context.CatchBlock.IsTopLevel;
    }
}

Note that this will only deal with exceptions that are not handled elsewhere (e.g. by Exception filters).

Problem

I had checked this link http://www.asp.net/web-api/overview/web-api-routing-and-actions/web-api-global-error-handling. In this link they mentioned like this ``` class OopsExceptionHandler : ExceptionHandler { public override void HandleCore(ExceptionHandlerContext context) { context.Result = new TextPlainErrorResult { Request = context.ExceptionContext.Request, Content = "Oops! Sorry! Something went wrong." + "Please contact support@contoso.com so we can try to fix it." }; } private class TextPlainErrorResult : IHttpActionResult { public HttpRequestMessage Request { get; set; } public string Content { get; set; } public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken) { HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.InternalServerError); response.Content = new StringContent(Content); response.RequestMessage = Request; return Task.FromResult(response); } } } ``` I don't know how to call this class in my Web API actions. So can any one give me the complete sample using this `ExceptionHandler`.

Original source