ASP.NET Core API，Mediatr 发送方法引发无法解析类型服务的异常

Question

我有一个 ASP.NET Core API，我正在尝试将 FluentValidation 与 Mediatr 一起使用。当前，当控制器方法尝试在它生成的 mediatr 实例上调用 Send 时：抛出的异常：Microsoft.Extensions.DependencyInjection.dll 中的“System.InvalidOperationException”：“尝试激活‘GetApplicationQueryValidator’时无法解析‘GetApplicationQuery’类型的服务。”查询、验证器和响应类如下所示：public class GetApplicationQuery : IRequest<Response>{    private string _name;    public GetApplicationQuery(string name)    {        _name = name;    }    public string Name { get { return _name; } }}public class GetApplicationQueryHandler : IRequestHandler<GetApplicationQuery, Response>{    public GetApplicationQueryHandler() { }    public async Task<Response> Handle(GetApplicationQuery request, CancellationToken cancellationToken)    {        return new Response("yadda yadda");                }}public class GetApplicationQueryValidator : AbstractValidator<GetApplicationQuery>{    public GetApplicationQueryValidator(GetApplicationQuery request)    {           RuleFor(m => m.Name).MinimumLength(30).WithMessage("Name must be greater than 30 characters, long");    }}public class Response{    private readonly IList<string> _messages = new List<string>();    public IEnumerable<string> Errors { get; }    public object Result { get; }    public Response() => Errors = new ReadOnlyCollection<string>(_messages);    public Response(object result) : this() => Result = result;    public Response AddError(string message)    {        _messages.Add(message);        return this;    }}我在 Startup 类中的配置如下所示：public void ConfigureServices(IServiceCollection services){    AddMediatr(services);    services.AddMvc().AddFluentValidation(fv =>         {            fv.RegisterValidatorsFromAssemblyContaining<Startup>();            fv.RunDefaultMvcValidationAfterFluentValidationExecutes = false;        }).SetCompatibilityVersion(CompatibilityVersion.Version_2_2);           }

Answer 1

GetApplicationQueryValidator正在GetApplicationQuery作为构造函数依赖项，但集合不知道它是否能够注入它。

也没有看到它是如何在该验证器中使用的。我建议GetApplicationQuery从构造函数中删除，因为它看起来并不需要。

public class GetApplicationQueryValidator : AbstractValidator<GetApplicationQuery> {

    public GetApplicationQueryValidator() { 

        RuleFor(m => m.Name).MinimumLength(30).WithMessage("Name must be greater than 30 characters, long");

    }

}