Man, you're messing with it all.
That is not the purpose of DataContext is object that should be regarded as the source of the information to be used/displayed in the control.
Why don't you just have DependencyProperty of type string in your FolderPicker, bind that property to whatever you want and bind the value of the TextBox.Text inside to FolderPicker.StringProperty?
Bigsby, Lisboa, Portugal
That is not the purpose of DataContext is object that should be regarded as the source of the information to be used/displayed in the control.
Why don't you just have DependencyProperty of type string in your FolderPicker, bind that property to whatever you want and bind the value of the TextBox.Text inside to FolderPicker.StringProperty?
Bigsby, Lisboa, Portugal