如何使用泛型创建流畅的界面

Evan Larsen 发表于 Dev

埃文·拉森（Evan Larsen）

我想创建一个可以像这样使用的流畅接口：

void Main() {
    ModelStateMappings.MapDomainModel<Book>().MapViewModel<BookViewModel>()
        .Properties(book => book.Author, vm => vm.AuthorsName)
        .Properties(book => book.Price, vm => vm.BookPrice);

    ModelStateMappings.MapDomainModel<Store>().MapViewModel<StoreViewModel>()
        .Properties(store => store.Owner, vm => vm.OwnersName)
        .Properties(store => store.Location, vm => vm.Location);
}

我想结束一个看起来像这样的集合：

static class ModelStateaMappings {
    private static IList<ModelMappings> mappings;
    // other methods in here to get it working
}

class ModelMappings {
    public Type DomainModelType {get;set;}
    public Type ViewModelType {get;set;}
    public IList<PropertyMapping> PropertyMappings {get;set;}
}

class PropertyMapping {
    public Expression<Func<object, object>> DomainProperty {get;set;}
    public Expression<Func<object, object>> ViewModelProperty {get;set;}
}

我无法完成上述工作，但是确实创建了类似的东西，并且以类似的方式工作，但是我并不特别喜欢必须设置流畅的界面。我宁愿像上面一样阅读它。

马辛·侏罗纪

您可以使用以下代码来实现

static class ModelStateMappings
{
    public static DomainModelMapping<TDomainModel> MapDomainModel<TDomainModel>()
    {
        // edit the constructor to pass more information here if needed.
        return new DomainModelMapping<TDomainModel>();
    }
}

public class DomainModelMapping<TDomainModel>
{
    public ViewModelMapping<TDomainModel, TViewModel> MapViewModel<TViewModel>()
    {
        // edit the constructor to pass more information here if needed.
        return new ViewModelMapping<TDomainModel, TViewModel>();
    }
}

public class ViewModelMapping<TDomainModel, TViewModel>
{
    public ViewModelMapping<TDomainModel, TViewModel>
        Properties<TDomainPropertyType, TViewModelPropertyType>(
            Expression<Func<TDomainModel, TDomainPropertyType>> domainExpr,
            Expression<Func<TViewModel, TViewModelPropertyType>> viewModelExpr)
    {
        // map here
        return this;
    }
}