How to binding and change VM property value when DataTrigger?

Question

Hi all,
Please see the below code. The current work is when mouse over myButton then set textbox value as 3. Then binding this value to ViewModel property, at this time, the new value of ViewModel property also be 3.
The textbox just like a bridge. Can I remove this bridge and change the VM property directly when <setter..... in myTrigger style? thanks.
<Style x:Key="myTrigger" TargetType="TextBox">
<Style.Triggers>
<DataTrigger Binding="{Binding IsMouseOver, ElementName=myButton}" Value="True">
<Setter Property="Text" Value="3"></Setter>
</DataTrigger>
</Style.Triggers>
</Style>

Answer 1

This definitely works:
<Button Height="50" Width="100">
<Button.Triggers>
<EventTrigger RoutedEvent="Button.MouseEnter">
<BeginStoryboard>
<Storyboard
Storyboard.Target="{Binding}"
Storyboard.TargetProperty="MyNum">
<DoubleAnimation To="3.0" />
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
Viewmodel:
public class MainWindowViewModel : DependencyObject
public double MyNum
get { return (double)GetValue(MyNumProperty); }
set
SetValue(MyNumProperty, value);
// Using a DependencyProperty as the backing store for MyNum. This enables animation, styling, binding, etc...
public static readonly DependencyProperty MyNumProperty =
DependencyProperty.Register("MyNum", typeof(double), typeof(MainWindowViewModel), new PropertyMetadata(callBack));
static void callBack(DependencyObject d, DependencyPropertyChangedEventArgs e)
Console.WriteLine(e.NewValue.ToString());
Hope that helps.
Recent Technet articles:
Property List Editing ;  
Dynamic XAML