#眉標=Vista開發技術
#副標=Windows Presentation Foundation（3）
#大標=Dependency Property
#作者=文／蔡學鏞


==<box>===========
Window
    Grid
        Button1
            TextBlock1
        Button2
            TextBlock2
==<end>==============





==<box>===========
Object
    DispatcherObject (abstract)
        DependencyObject
            Visual (abstract)
                UIElement
                    FrameworkElement
                        Control
==<end>==============




==程式1		<box>===========
public double FontSize
{
    get
    {
        return fntsize;
    }
    set
    {
        fntsize = value;
        ...
    }
}
==<end>==============





==程式2		<box>===========
public class Control: FrameworkElement
{
    ...
    public static readonly DependencyProperty FontSizeProperty;
    ...
}
==<end>==============





==程式3		<box>===========
FontSizeProperty = DependencyProperty.Register("FontSize", typeof (double),
                                               typeof(Control));
==<end>==============





==程式3  <box>===========
public class Control: FrameworkElement
{
    ...
    public static readonly DependencyProperty FontSizeProperty;
    ...
    static Control()
    {
        FrameworkPropertyMetadata metadata = new FrameworkPropertyMetadata();
        metadata.DefaultValue = 11;
        metadata.AffectsMeasure = true;
        metadata.Inherits = true;
        metadata.IsDataBindingAllowed = true;
        metadata.DefaultUpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
        FontSizeProperty =
        DependencyProperty.Register("FontSize", typeof(double),
        typeof(Control), metadata, ValidateFontSize);
    }
    static bool ValidateFontSize(object obj)
    {
        double dFontSize = (double) obj;
        return dFontSize > 0 && dFontSize <= 35791;
    }
    ...
}
==<end>==============





==程式4		<box>===========
public class Control: FrameworkElement
{
    ...
    public double FontSize
    {
        set
        {
            SetValue(FontSizeProperty, value);
        }
        get
        {
            return (double) GetValue(FontSizeProperty);
        }
    }
    ...
}
==<end>==============




==關於作者<box>===========
蔡學鏞
清華大學資訊工程碩士。曾任軟體公司經理、大學講師。著有「Java夜未眠」，譯有「深入淺出設計模式」等書，專欄包括「台灣微軟MSDN.NET大內高手」。目前的研究領域在Natural Language Processing。
==<end>==============