Help me plz with generics

I'm trying to make an interface with methods and I don't understand how to set input and output parameter for interfaces

i have a class with method

public TeachersDto[] MapToDto(Teachers[] entities, Dictionary<string, ParameterData> data)

public Teachers[] MapDto(TeachersDto dto, Dictionary<string, ParameterData> Data)

i try

public interface ITeachersMapper<RInput, Dictionary<string, RInput2>, TOutput>
{
    TDto[] MapToDto(TEntity[] entities, Dictionary<string, TInput> data);

    TEntity[] MapDto(TDto[] dtos, Dictionary<string, TInput> data);

}

How write input and output generic parameter for interface?

CodePudding user response：

It's unclear how you are trying to use this interface since your interface doesn't match with your implementation that you give in the question, but I think this is what you are looking for.

Keep in mind that generic parameters can be called whatever you want, but T is just convention, so name your generic parameters something to make it obvious what they represent.

Also, you can't have a mixture of a specific type like Dictionary with a generic type. You can have a generic type with type constraints using where, but most likely you just want a generic type to define the ParameterData and don't need any of the Dictionary stuff in the generic specification.

I changed your classes to be just Teacher and TeacherDto since classes usually take a singular form.

    public interface IEntityMapper<TEntity, TParameterData, TDto>
    {
        TDto[] MapToDto(TEntity[] entities, Dictionary<string, TParameterData> data);
        TEntity[] MapDto(TDto[] dtos, Dictionary<string, TParameterData> data);
    }
    
    public class TeacherMapper : ITeacherMapper<Teacher, ParameterData, TeacherDto>
    {
        public TeacherDto[] MapToDto(Teacher[] entities, Dictionary<string, ParameterData> data)
        {
            //..mapping to DTO here
        }
        public Teacher[] MapDto(TeacherDto[] dto, Dictionary<string, ParameterData> Data)
        {
            //..mapping to domain here
        }
    }