棱镜地区不可处置意见或的ViewModels [英] Prism Regions Not Disposing Views or ViewModels

问题描述

我认为棱镜地区会自动检测并调用的Dispose 的实施的IDisposable 接口的任何意见或视图模型。事实证明我错了。

I assumed that Prism Regions would automatically detect and call Dispose any views or view models that implemented the IDisposable interface. Turns out I was wrong.

然后我考虑实施 IActiveAware ，所以我可以处理我自己我的看法/的ViewModels，但似乎相当的hackish 。我宁愿把它自动完成的。

I then considered implementing IActiveAware so I could dispose my views/viewmodels on my own, but that seems rather hackish. I'd rather have it done automatically.

我如何配置棱镜地区自动配置我的看法和视图模型实现的IDisposable ？

How can I configure Prism Regions to automatically dispose my views and view models that implement IDisposable?

推荐答案

搜索无远弗届的互联网上，并没有找到任何真正的解决方案后，我开发了我自己自 RegionBehavior ，这竟然非常漂亮的工作。

After searching far and wide on the internet, and not finding any real solution, I developed my own custom RegionBehavior, which turned out to work very nicely.

行为监听区域的观点收集的任何变化，并能在任何有删除，它会检查并要求的Dispose 对视图和/或视图模型，只有当他们执行<$ C $ 。C>的IDisposable

The behavior listens to the region's view collection for any changes, and when any are removed, it checks for and calls Dispose on the view and/or view model, only if they implement IDisposable.

class DisposeClosedViewsBehavior : RegionBehavior
{
    protected override void OnAttach()
    {
        Region.Views.CollectionChanged += Views_CollectionChanged;
    }

    private void Views_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (e.Action != NotifyCollectionChangedAction.Remove) return;

        foreach (var removedView in e.OldItems)
        {
            IDisposable disposableView = removedView as IDisposable;
            IDisposable disposableViewModel;

            var iviewView = removedView as IView;
            if (iviewView != null)
            {
                disposableViewModel = iviewView.DataContext as IDisposable;
            }
            else
            {
                var frameworkElementView = removedView as FrameworkElement;
                disposableViewModel = frameworkElementView?.DataContext as IDisposable;
            }

            disposableView?.Dispose();
            disposableViewModel?.Dispose();
        }
    }
}

最后一步是为了堵塞这种行为变成棱镜通过重写引导程序 ConfigureDefaultRegionBehaviors 方法：

protected override IRegionBehaviorFactory ConfigureDefaultRegionBehaviors()
{
    var factory = base.ConfigureDefaultRegionBehaviors();

    factory.AddIfMissing(nameof(DisposeClosedViewsBehavior), typeof(DisposeClosedViewsBehavior));

    return factory;
}

工程就像一个魅力！

Works like a charm!

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