Blazor FluentValidation 如何将依赖项注入 AbstractValidator

Question

I am using FluentValidator for a current Blazor-Server Project.

Now i need to inject my database service class for validate duplication and stuff like that.

 public class StockValidator : AbstractValidator<LagertypModel>
{
    private StockOverviewService _stockservice;

    public StockValidator(StockOverviewService stockservice)
    {
        _stockservice = stockservice;
        RuleFor(LagertypModel => LagertypModel.Lagertyp).NotEmpty().MaximumLength(4).Must(Lagertyp => {
            return _stockservice.validateStockTypeCU(Lagertyp).Result;
        });


    }
}

But when i do that i get the error that StockValidator needs to have a parameterless contructor.

How can i inject my dependency now?

Answer 1

Where you instantiate your StockValidator class make sure you pass your service into it like so:

Program.cs

builder.Services.AddSingleton<StockOverviewService>();

StockOverviewService.cs

private StockValidator_validator;
public StockOverviewService(LiveConnectionString connectionString)
        {
            _connectionString = connectionString;
            _validator = new StockValidator(this);
        }

StockValidator.cs

public class StockValidator : AbstractValidator<LagertypModel>
{
    private StockOverviewService _stockservice;

    public StockValidator(StockOverviewService stockservice)
    {
        _stockservice = stockservice;
        RuleFor(LagertypModel => LagertypModel.Lagertyp).NotEmpty().MaximumLength(4).Must(Lagertyp => {
            return _stockservice.validateStockTypeCU(Lagertyp).Result;
        });


    }
}

Assuming your StockOverviewService uses async methods for accessing a DB/Api, I don't recommend this approach because you're making the code run synchronously here:

return _stockservice.validateStockTypeCU(Lagertyp).Result;

but it will work.