当前位置：文江博客话题详情

WPF 如何使用值转换器绑定两个不同但相关类型的可观察集合？

发布于 2024-10-19 12:31:04 字数 146 浏览 1 评论 0原文

我有一个自定义控件，其中包含一个可观察集合（DP），其中包含某种类型的对象。我想将其绑定到另一个可观察集合，该集合在我的虚拟机中保存不同类型的对象。我该怎么做？

我应该做这样的事情吗？

编辑。当然，当集合中的元素在任一侧被修改时，绑定应该起作用。

原文

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

嗼ふ静 2024-10-26 12:31:04

Meleak 的评论是正确的，您应该以某种方式将一个集合转换为另一个集合并同步它们。这是我上次的做法：

View（我在下面将其命名为 MyControl）具有 IEnumerable 类型的属性 Items< br>
DataContext 具有 IEnumerable 类型的属性 Items

class CollectionsConverter : IValueConverter
{
    public object Convert(object value, ...)
    {
        var source = (ObservableCollection<Source>)value;
        var target = new ObservableCollection<Target>(source.Select(/* Convert items somehow /);
        // subscribe to both target's and source's 'CollectionChanged' events
        // and propagate them back and forth to another collection.
        // Propagated events should have converted items of course

        return target;
    }
    ...
}

然后在 XAML 中：

<MyControl Items="{Binding Items, Converter=CollectionsConverter}" />

关于转换每个项目 - 它可以是通用代码，它将动态确定如何转换 Source 到 Target ，反之亦然，或者它应该是一个代码，它知道它将转换哪些确切类型以及如何转换它们。

Meleak's comment is correct, you should somehow transform one collection into another and sync them. Here is how I did it last time:

View (I've named it MyControl below) has property Items of type IEnumerable<Target>
DataContext has property Items of type IEnumerable<Source>

class CollectionsConverter : IValueConverter
{
    public object Convert(object value, ...)
    {
        var source = (ObservableCollection<Source>)value;
        var target = new ObservableCollection<Target>(source.Select(/* Convert items somehow /);
        // subscribe to both target's and source's 'CollectionChanged' events
        // and propagate them back and forth to another collection.
        // Propagated events should have converted items of course

        return target;
    }
    ...
}

Then in XAML:

<MyControl Items="{Binding Items, Converter=CollectionsConverter}" />

Regarding converting each item - it can be either generic code which will dynamically determine how to convert Source to Target and vice versa or it should be a code which will know which exact types it will convert and how to convert them.

回复收藏 0 原文

落叶缤纷 2024-10-26 12:31:04

ValueConverters 不按照您描述的方式工作，您必须手动创建一个新集合。

这并不能直接回答你的问题，但是在ReactiveUI（http://www.reactiveui.net）中，这种情况非常简单：

var derivedColl = someCollection.CreateDerivedCollection(x => new SomeOtherClass(x));

ValueConverters don't work the way you're describing, you have to create a new collection by-hand.

This doesn't answer your question directly, but in ReactiveUI (http://www.reactiveui.net), this scenario is quite easy:

var derivedColl = someCollection.CreateDerivedCollection(x => new SomeOtherClass(x));

回复收藏 0 原文

你在看孤独的风景 2024-10-26 12:31:04

使用实现 IValueConverter 的自定义 Converter 类



    public class ObserverTypeConverter:IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            //return your dependency type from here     
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            //return your view model type from here, this will get fired if your binding is two way
        }
    }

Use your custom Converter class implementing IValueConverter



    public class ObserverTypeConverter:IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            //return your dependency type from here     
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            //return your view model type from here, this will get fired if your binding is two way
        }
    }

回复收藏 0 原文

~没有更多了~