绑定到.NET中多个索引的属性？ [英] Binding to multiple indexed properties in .NET?

问题描述

绑定到这个属性是相当简单：

Binding to this property is fairly simple:

public Foo MyFoo {get; set;}

public class Foo
{
    public object this[object key]
}

由于这里在XAML中，你可以这样做：

Because here in XAML you can do:

<Label Content="{Binding MyFoo["key"]}"/>

但是，如果我有第二个索引属性？

But what if I had a second indexed property?

我知道这是不能直接在C＃中，但在VB.NET它。

I know this is not directly possible in C#, but in VB.NET it is.

Default Public Property Item(key As Object) As Object 'equivalent to this[...]'
Public Property Item2(key As Object) As Object 'a second indexed property!'

这些都是一些我已经试过了绑定的：

These are some of the bindings I've tried:

<Label Content="{Binding MyFoo["key"]}"/>
<Label Content="{Binding MyFoo.Item["key"]}"/>
<Label Content="{Binding MyFoo.Item2["key"]}"/>

第一个结合仍然可以工作，但其他两个不会。

The first binding will still work, but the other two won't.

有没有直接的解决办法，还是我需要一个解决办法？

Is there a direct solution to this, or do I need a workaround?

推荐答案

JOBO 的建议后放置VB .NET类集会，并提到它在 C＃的项目，
我发现了，为什么你不能的直接的绑定到多个索引的属性。

After Jobo's suggestion to place the VB.NET class in an assembly, and reference to it in a C# project,
I found out why you can't directly bind to multiple indexed properties.

引擎盖下，是为每个生成的两种方法的额外的索引属性： get_X 和 set_X ，其中 X 是索引属性的名称。

Under the hood, two methods are generated for every extra indexed property: get_X and set_X, where X is the name of the indexed property.

这意味着VB.NET索引的属性，未标记为默认，实际上不存在。这就是为什么在我的问题的XAML绑定说，找不到属性项目或项目2 ...

This means that the VB.NET indexed properties, that are not marked as Default, actually don't exist. This is why the XAML bindings in my question said that it could not find properties Item or Item2...

也许，有多种变通办法问题。你可以，例如，创建一个小的类，它包含一个索引属性，然后在这个类的多个实例的主窗口。

Probably, there are multiple workarounds for this problem. You could, for example, create a small class that contains an indexer property, and then have multiple instances of that class in your MainWindow.

另一种解决方法可以是结合 get_X 的返回值，但我只能想象如何刺激性这样会得到的，因为这样一来，你不会得到的好处 INotifyPropertyChanged的。

Another workaround could be binding to the return value of get_X, but I could only imagine how irritating this would get, since this way you won't get the benefits of INotifyPropertyChanged.

这篇关于绑定到.NET中多个索引的属性？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！