使用 Mono droid 和 slodge mvvmcross 从堆栈中删除活动 [英] Remove activity from stack using Mono droid and slodge mvvmcross

问题描述

我试图找到一种从堆栈中删除活动的方法 - 我们的应用程序中有一个流程:活动/视图模型 a -> 活动/视图模型 b -> 活动/视图模型 c.在 c 中，用户可以选择日期或返回.如果他回去，他应该回到b.但是，如果他选择了一个日期，他将被转发到活动/视图模型 b 的新实例，而活动/视图模型 b 的旧"实例已过时，应删除.

I am trying to find a way to remove an activity from the stack- We have a flow in our app: activity/viewmodel a -> activity/viewmodel b ->activity/viewmodel c. In c the user have the posibility of choosing a date or go back. If he goes back he should be returned to b. However if he chooses a date he is fowarded to a new instance of activity/viewmodel b and the "old" instance of activity/viewmodel b is obsolete and should be removed.

来自 Stuart Lodge(在类似线程上，仅用于单声道触摸)的建议是使用 RequestRemoveBackStep()，但我不确定如何使用它，而且我找不到示例.

A suggestion from Stuart Lodge (on a similar thread, just for mono touch) was to use RequestRemoveBackStep() but I am not sure how to use it and I cant find an example.

谁能指出我正确的方向?

Can anyone point me in the right direction?

问候

推荐答案

RequestRemoveBackStep() 方法是 IMvxViewDispatcher 接口的成员，在一些平台上实现:

The RequestRemoveBackStep() method is a member of the IMvxViewDispatcher interface and is implemented on some platforms:

public interface IMvxViewDispatcher : IMvxMainThreadDispatcher
{
    bool RequestNavigate(MvxShowViewModelRequest request);
    bool RequestClose(IMvxViewModel whichViewModel);
    bool RequestRemoveBackStep();
}

来自 https://github.com/slodge/MvvmCross/blob/vnext/Cirrious/Cirrious.MvvmCross/Interfaces/Views/IMvxViewDispatcher.cs

但是，始终执行此操作并不完全简单......例如，在 Droid 上，它目前实现为:

However, its not entirely simple to always do this... so on Droid, for example, it is currently implemented as:

    public bool RequestRemoveBackStep()
    {
        // not supported on Android? Not sure how to do this currently...
        return false;
    }

来自 https://github.com/slodge/MvvmCross/blob/vnext/Crillous/Cirrious.MvvmCross.Droid/Views/MvxAndroidViewDispatcher.cs

记录了有关此功能的问题 - 例如https://github.com/slodge/MvvmCross/issues/80 - 但似乎很可能此功能可能会从未来的 Mvx 实现中简单地删除 - 特别是因为对于每个平台上的每个视图都不太容易做到.

There are issues logged about this functionality - e.g. https://github.com/slodge/MvvmCross/issues/80 - but it seems likely that this functionality might simply be dropped from future Mvx implementations - especially as it's not very easy to do for every view on every platform.

如果您现在需要这种类型的功能，那么您需要找到自己的方式来实现此功能...取决于您的具体用例是什么(抱歉 - 您当前用例的详细信息不是从问题中我很清楚).

If you need this type of functionality now, then you'll need to find your own way of implementing this functionality... depending on what your specific use case is (sorry - the details of your current use case aren't clear to me from the question).

有几种可用的技术路线，包括:

There are several technical routes available including:

• 使用 NoHistory 标志
• 使用 RequestClose(oldviewModel) 调用
• 将逻辑添加到您的 Presenter
• 使用 Messenger 请求关闭自己的视图.

• using NoHistory flags
• using RequestClose(oldviewModel) calls
• adding logic to your Presenter
• using a Messenger to request views close themselves.

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