How do I read Text property of silverlight toolkit NumericUpDown control?

I want to read value entered in the NumericUpDown control. How do i read it?

XAML Layout is follows

  <StackPanel Style="{StaticResource StackPanelStyle_LableValue}">
                            <TextBlock Style="{StaticResource TextBlockStyle}" 
                                       Text="{Binding Path=ViewItem.A开发者_运维问答ddition, Source={StaticResource LocalizedStrings }}" />
                            <inputToolkit:NumericUpDown Style="{StaticResource NumericUpdownStyle_Addition}"
                                                        Value="{Binding Items.RightSpecGlass.Addition, Mode=TwoWay}" 
                                                        TabIndex="8" />
                        </StackPanel>

You can use

numericUpDown.Value; // To get decimal value of control

or

numericUpDown.Text; // To get value as string of control

Well, Since you have bind your view context, I think there is no reason to avoid get NumericUpDown's value except :

1- Maybe you forgot to initialize those classes or properties Items and/or RightSpecGlass

2- Your class doesn't implement INotifyPropertyChanged to raise when any control's value change in view. Addition property has to raise property change event in its setter.

    public event PropertyChangedEventHandler PropertyChanged;
    public virtual void RaisePropertyChanged(string propertyName)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }
    private int _addition;
    public Int32 Addition
    {
        get { return _addition; }
        set
        {
            _addition= value;
            RaisePropertyChanged("Addition");
        }
    }

hope this help.