How Can I Handle Exceptions from All Filters, Including Authorization Filters, in ASP.NET Core Web APIs?

ASP.NET Core Web API Exception Handling: Understanding the Limitations of Filters

In ASP.NET Core Web API, exception handling is significantly different from traditional ASP.NET Web API. Although exception handling filters can be used, they have certain limitations.

In the provided example, ErrorHandlingFilter cannot catch the exception in AuthorizationFilter. This is because filters are executed sequentially, and each filter is responsible for handling its own exceptions. If an exception is thrown in a previous filter, it will interrupt the execution of subsequent filters.

Handle exceptions for all filters

To handle exceptions for all filters, including application exceptions, you can leverage the IExceptionHandler interface. Here’s how to do it:

using Microsoft.AspNetCore.Diagnostics;

class MyExceptionHandler : IExceptionHandler
{
    public async ValueTask<bool> TryHandleAsync(
        HttpContext context, 
        Exception exception,
        CancellationToken cancellation)
    {
        // 异常响应对象
        var error = new { message = exception.Message };
        await context.Response.WriteAsJsonAsync(error, cancellation);
        return true;
    }
}

Middleware registration:

Register as follows MyExceptionHandler Middleware:

builder.Services.AddExceptionHandler<MyExceptionHandler>();
app.UseExceptionHandler(_ => { });

This middleware will catch and handle all exceptions, including those from filters.

Key points:

• IExceptionHandler The implementation can chain calls in the order of registration.
• Return TryHandleAsync from true if the exception was handled; otherwise, return false to pass the exception to the next handler.

The above is the detailed content of How Can I Handle Exceptions from All Filters, Including Authorization Filters, in ASP.NET Core Web APIs?. For more information, please follow other related articles on the PHP Chinese website!