Using Hashtable as DataContext (for WPF/XAML Binding)

问题

In code I have a Hashtable named MyHashtable. This Hashtable contains an element with key="Value", value=3. I'm currently trying to bind this value to a textbox. This is my XAML code:

<TextBlock Margin="4" Text="{Binding MyHashtable[Value]}" />
<TextBlock Margin="4" DataContext="{Binding MyHashtable}" Text="{Binding [Value]}" />

Q: Why does the second binding not work, while the first binding works just great?

For the second binding I have tried other bindings for the text, such as: Value, this[Value] or even Me[Value], but they all did not work.

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Using Item[Value] gives me an interesting exception: Parameter count mismatch. Does somebody understand this? This is because of differences between C# and VB.NET. See this question.

回答1:

For second option you can just use this:

<TextBlock Margin="4" 
     DataContext="{Binding MyHashtable}" 
     Text="{Binding RelativeSource={x:Static RelativeSource.Self},
            Path=DataContext[Value]}" />

来源：https://stackoverflow.com/questions/14623728/using-hashtable-as-datacontext-for-wpf-xaml-binding