Nullable Dependency Properties and Binding

Author’s Note: If you’re here just for a solution and are not interested in the extraneous bits, click here to jump to the workaround details.

First, some background…

Let’s say you’re building a user control and one of your control’s properties needs to be a three state boolean (true, false, null).

No sweat, we’ll just create a nullable boolean (bool?) dependency property:

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public static readonly DependencyProperty ValueProperty =     DependencyProperty.Register("Value",         typeof(bool?),         typeof(TestControl),         new PropertyMetadata(null));

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