How can I implement error handling in ASP.NET Core Web API?

How can I implement error handling in ASP.NET Core Web API?

You can implement error handling in ASP.NET Core Web API by using middleware, exception filters, or custom error responses.

What is the best practice for returning error responses?

A common practice is to return a standardized error response format, including status code, message, and any additional details.

Can you show me an example of custom middleware for error handling?

Sure! You can create a custom middleware that catches exceptions and formats the response like this:

public class ErrorHandlingMiddleware {
    private readonly RequestDelegate _next;

    public ErrorHandlingMiddleware(RequestDelegate next) {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context) {
        try {
            await _next(context);
        } catch (Exception ex) {
            await HandleExceptionAsync(context, ex);
        }
    }

    private Task HandleExceptionAsync(HttpContext context, Exception ex) {
        context.Response.ContentType = "application/json";
        context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
        return context.Response.WriteAsync(new ErrorResponse {
            Message = "An error occurred while processing your request.",
            Details = ex.Message
        }.ToString());
    }
}

How do I register this middleware in the Startup class?

You can register the middleware in the Configure method of your Startup class like this:

public void Configure(IApplicationBuilder app, IWebHostEnvironment env) {
    app.UseMiddleware<ErrorHandlingMiddleware>();
    // other middleware registrations
}