如何让中间件有条件地转发请求 C#，使用 yarp

Question

我正在 Startup.cs 文件中注册一个中间件。 在中间件中，我根据条件转发请求。 但是，如果不满足条件，我希望处理默认执行流程（不转发请求，但继续执行预期流程）。 但是，如果我在不满足条件时不执行任何操作，则不会返回任何内容。 这是代码

    app.UseEndpoints(endpoints =>
    {
        endpoints.Map("path/{**catch-all}", async httpContext =>
        {
            if (conditionIsMet)
            {
                var error = await forwarder.SendAsync(httpContext, endpoint), httpClient, requestOptions, transformer);

                // Check if the proxy operation was successful
                if (error != ForwarderError.None)
                {
                    var errorFeature = httpContext.Features.Get<IForwarderErrorFeature>();
                    var exception = errorFeature.Exception;
                }
            }
            else
            {
                //how do i have the default controller that is mapped to this endpoint handle the request?
            }
        });
    });

Answer 1

使用中间件来做到这一点：

app.Use(async (httpContext, next) =>
{
    if (httpContext.Request.Path.StartsWithSegments("path") && conditionIsMet)
    {
        var error = await forwarder.SendAsync(httpContext, endpoint, httpClient, requestOptions, transformer);

        // Check if the proxy operation was successful
        if (error != ForwarderError.None)
        {
            var errorFeature = httpContext.Features.Get<IForwarderErrorFeature>();
            var exception = errorFeature.Exception;
        }

        return;
    }
    return next(httpContext);
});

app.UseEndpoints(endpoints =>
{
    endpoints.MapControllers();
});