在接口实现的接口属性？ [英] Implementing interface properties in interfaces?

问题描述

我有一个code碱基我想用这两个一个ASP.NET MVC和WPF / MVVM前端。业务对象实现为接口和业务逻辑使用这些接口传递数据。

I have a code base I want to use for both an ASP.NET MVC and a WPF/MVVM front end. The business objects are implement as interfaces and the business logic uses these interfaces for passing data.

说我有实现IEnumerable接口，我在一个属性上。是否有可能有不同版本的界面使用的IEnumerable的不同实现？什么，我试图完成一个例子：

Say I have a property on my interface that implements IEnumerable. Is it possible to have different versions of this interface use different implementations of IEnumerable? An example of what I am trying to accomplish:

class Reporting
{
    public bool RunReport(IReportParams Params);
}

interface IReportParams
{
    IEnumerable<Guid> SelectedItems { get; }
    IEnumerable<StatusEnum> SelectedStatuses { get; }
}

class MvcReportParams : IReportParams
{
    public List<Guid> SelectedItems { get; set; }
    public List<StatusEnum> SelectedStatuses { get; set; }
}

class WpfReportParams : IReportParams
{
    public ObservableCollection<Guid> SelectedItems { get; set; }
    public ObservableCollection<StatusEnum> SelectedStatuses { get; set; }
}

可以这样做？

编辑：我也应该问怎么了，因为当我尝试这一点，我得到的错误与此类似：

I should also have asked "how", because when I try this, I get errors similar to this:

MvcReportParams不实现接口成员'IReportParams.SelectedStatuses。 MvcReportParams.SelectedStatuses无法实现IReportParams.SelectedStatuses'，因为它不具有匹配的返回类型System.Collections.Generic.IEnumerable

'MvcReportParams' does not implement interface member 'IReportParams.SelectedStatuses'. 'MvcReportParams.SelectedStatuses' cannot implement 'IReportParams.SelectedStatuses' because it does not have the matching return type of 'System.Collections.Generic.IEnumerable'

的ObservableCollection和列表两种完全实现IEnumerable，所以这似乎没有道理给我。

ObservableCollection and List both absolutely implement IEnumerable, and so this does not seem to make sense to me.

最后修改

嗯，有人贴出了答案，但他们删除它由于某种原因，所以我不能将它标记为解决方案。下面是我落得这样做：

Well, someone posted the answer, but they deleted it for some reason, so I can't mark it as the solution. Here's what I ended up doing:

interface IReportParams
{
    IEnumerable<Guid> SelectedItems { get; }
    IEnumerable<StatusEnum> SelectedStatuses { get; }
}

class MvcReportParams : IReportParams
{
    // Properties that the modelbinder dims and sets up
    public List<Guid> SelectedItems { get; set; }
    public List<StatusEnum> SelectedStatuses { get; set; }

    // Explicityly implement my interface
    IEnumerable<Guid> IReportParams.SelectedItems
    {
        get { return SelectedItems; }
    }

    IEnumerable<StatusEnum> IReportParams.SelectedStatuses
    {
        get { return SelectedStatuses; }
    }
}

class WpfReportParams : IReportParams
{
    // Properties that my view dims and modifies
    public ObservableCollection<Guid> SelectedItems { get; set; }
    public ObservableCollection<StatusEnum> SelectedStatuses { get; set; }

    // Explicityly implement my interface
    IEnumerable<Guid> IReportParams.SelectedItems
    {
        get { return SelectedItems; }
    }

    IEnumerable<StatusEnum> IReportParams.SelectedStatuses
    {
        get { return SelectedStatuses; }
    }
}

这是样板code多行来写，但我喜欢更明确的反正。

It's more lines of boilerplate code to write, but I like being more explicit anyways.

推荐答案

我可能会用只读属性实现这一点。它更好地初步实践为客户端添加/删除/更新项目现有的集合中，而不是完全取代的集合。

I would probably implement this with read-only properties. It better pratice for the client to add/remove/update items in an existing collection rather than replace the collection altogether.

interface IReportParams
{
    IEnumerable<Guid> SelectedItems { get; }
    IEnumerable<StatusEnum> SelectedStatuses { get; }
}

class MvcReportParams : IReportParams
{
    public MvcReportParams()
    {
        SelectedItems = new Collection<Guid>();
        SelectedStatuses = new Collection<StatusEnum>();
    }

    public IEnumerable<Guid> SelectedItems { get; private set; }
    public IEnumerable<StatusEnum> SelectedStatuses { get; private set; }
}

class WpfReportParams : IReportParams
{
    public WpfReportParams()
    {
        SelectedItems = new ObservableCollection<Guid>();
        SelectedStatuses = new ObservableCollection<StatusEnum>();
    }

    public IEnumerable<Guid> SelectedItems { get; private set; }
    public IEnumerable<StatusEnum> SelectedStatuses { get; private set; }
}

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