Binding property from a property

Question

how can I do a bind if the property to show is a property from a property, like this case:

Xaml:

<TextBox Text="{Binding log.Message}"/> ????

In the class defined as Datacontext, I declare a log variable:

public Log log = new Log();

the Log class:

public class Log : INotifyPropertyChanged { public static string Message{ get { return message; } } ....

This is pretty much how it should be done. Are you sure you have bound the datacontext correctly in the first place? — Ivan Crojach Karačić
– Ivan Crojach Karačić, Commented Oct 2, 2013 at 12:36
The static in your property can't work. See my answer to deal with different situations, if the static is intended, you don't need to care about the current DataContext. — dowhilefor
– dowhilefor, Commented Oct 2, 2013 at 12:39

dowhilefor · Accepted Answer · 2013-10-02 12:38:24Z

Your question is a bit unclear to me, but i give it a shot:

If the DataContext is an instance of the Log class, and the property is non static. Than the proper binding would be

<TextBox Text="{Binding Message}"/>

From there you can easily nest your bindings. For example if Log would have an instance of a class

public class Log { public MessageHandler Message {get;set;} }

which would have a property LocalizedMessage, it would simply be

<TextBox Text="{Binding Message.LocalizedMessage}"/>

If you want to bind to a static property, which your Message property currently is:

<TextBox Text="{Binding Source={x:Static MyNs:Log.Message}, Path=.}"/>

Also worth mentioning, that for first scenario (non-static property) to work, log should be a property, not a field. Which is probably the reason why OP is having problems in the first place.
You a right. I think he confused the name of his variable as a requirement to put into the binding. Which of course is not necessary.

Community · Accepted Answer · 2017-05-23 12:29:32Z

You can't bind static properties to XAML. Only .Net 4.5 enables that, and even that with some work. see: WPF 4.5 – Part 9 : binding to static properties. You can find the way there.

If you can't use .Net 4.5, check out this SO thread for another workaround.

Programmer · Accepted Answer · 2013-10-02 12:43:17Z

The problem with what you wrote is that Message is a static property, so you're not suppose to get it from the log object, but from the Log class:

<Window.Resources> <local:Log x:Key="logClass"/> </Window.Resources>

<TextBox Text="{Binding Source={StaticResource logClass}, Path=Message}"/

3 Answers 3