使用ModelLocator來管理視圖

之前只是簡單的介紹了一下ModelLocator的用法，在這里要把模型和視圖結合起來，通過模型來來控制視圖。在Silverlight中我們可以看到所有新建立的xaml都是繼承自UserControl，所以在這里更新歡稱視圖為控件。

至此給出一個項目的結構圖出來。這里我是習慣把從網上下載的第三方類庫放在項目中一個Lib的目錄下，如果有源碼的話直接加入解決方案中也是可以的。

所有的用戶控件都是創建在Controls目錄下。這里提到了創建用戶控件，所以就不得不提一下控件的DependencyProperty屬性，他是控件的一個靜態的屬性，主要用來做數據綁定。

為控件創建DependencyProperty屬性

創建了DependencyProperty后能更方便的和ModelLocator進行綁定。處理一些界面上的動畫效果也能更加的靈活。
這里給出一個標準的代碼
?? ? ? ?//?Using?a?DependencyProperty?as?the?backing?store?for?TheName.??
????????//?This?enables?animation,?styling,?binding,?etc
????????public?static?readonly?DependencyProperty?TheNameProperty?=
????????????DependencyProperty.Register("TheName",
????????????????????????????????????????typeof(string),
????????????????????????????????????????typeof(Page),
????????????????????????????????????????new?PropertyMetadata("",
??????????????????????????????????????????new?PropertyChangedCallback(
????????????????????????????????????????????OnTheNameChanged)));

????????static?void?OnTheNameChanged(object?sender,
?????????????????????????????????????DependencyPropertyChangedEventArgs?args)
????????{
????????????//?Get?reference?to?self
????????????Page?source?=?(Page)sender;

????????????//?Add?Handling?Code
????????????string?newValue?=?(string)args.NewValue;
????????} 更多關于創建自定義用戶控件的請查看winter-cn?前輩的《Silverlight 2 Customized Control 開發》?，寫的非常的詳細。（我這里就不再去重復的發明輪子了）

創建一個會變色的控件

這里首先看Demo

學習是一個溫故知新的過程，之前我寫過一篇《動態創建Storyboard》這里就用上他再結合DependencyProperty做一個會變色的控件。

運用DependencyProperty結合Storyboard創建控件
?? ?public?partial?class?BackGorund?:?UserControl
????{


????????public?byte?R
????????{
????????????get?{?return?(byte)GetValue(RProperty);?}
????????????set?{?SetValue(RProperty,?value);?}
????????}

????????//?Using?a?DependencyProperty?as?the?backing?store?for?R.??
????????//?This?enables?animation,?styling,?binding,?etc
????????public?static?readonly?DependencyProperty?RProperty?=
????????????DependencyProperty.Register("R",
????????????????????????????????????????typeof(byte),
????????????????????????????????????????typeof(BackGorund),
????????????????????????????????????????new?PropertyMetadata((byte)0,
????????????????????????????????????????????new?PropertyChangedCallback(OnRChanged)));

????????static?void?OnRChanged(object?sender,?DependencyPropertyChangedEventArgs?args)
????????{
????????????//?Get?reference?to?self
????????????BackGorund?source?=?(BackGorund)sender;

????????????source.changeColor();
????????}



????????public?byte?G
????????{
????????????get?{?return?(byte)GetValue(GProperty);?}
????????????set?{?SetValue(GProperty,?value);?}
????????}

????????//?Using?a?DependencyProperty?as?the?backing?store?for?G.??
????????//?This?enables?animation,?styling,?binding,?etc
????????public?static?readonly?DependencyProperty?GProperty?=
????????????DependencyProperty.Register("G",
????????????????????????????????????????typeof(byte),
????????????????????????????????????????typeof(BackGorund),
????????????????????????????????????????new?PropertyMetadata((byte)0,
????????????????????????????????????????????new?PropertyChangedCallback(OnGChanged)));

????????static?void?OnGChanged(object?sender,?DependencyPropertyChangedEventArgs?args)
????????{
????????????//?Get?reference?to?self
????????????BackGorund?source?=?(BackGorund)sender;

????????????source.changeColor();
????????}



????????public?byte?B
????????{
????????????get?{?return?(byte)GetValue(BProperty);?}
????????????set?{?SetValue(BProperty,?value);?}
????????}

????????//?Using?a?DependencyProperty?as?the?backing?store?for?B.??
????????//?This?enables?animation,?styling,?binding,?etc
????????public?static?readonly?DependencyProperty?BProperty?=
????????????DependencyProperty.Register("B",
????????????????????????????????????????typeof(byte),
????????????????????????????????????????typeof(BackGorund),
????????????????????????????????????????new?PropertyMetadata((byte)0,
????????????????????????????????????????????new?PropertyChangedCallback(OnBChanged)));

????????static?void?OnBChanged(object?sender,?DependencyPropertyChangedEventArgs?args)
????????{
????????????//?Get?reference?to?self
????????????BackGorund?source?=?(BackGorund)sender;

????????????source.changeColor();
????????}



????????public?void?changeColor()
????????{
????????????colorAnim.To?=?Color.FromArgb(255,?R,?G,?B);
????????????storyboard.Begin();
????????}



????????private?ColorAnimation?colorAnim;
????????private?Storyboard?storyboard;

????????public?BackGorund()
????????{
????????????InitializeComponent();

????????????storyboard?=?new?Storyboard();

????????????Brush?br?=?this.LayoutRoot.Background;
????????????colorAnim?=?new?ColorAnimation();
????????????colorAnim.To?=?Color.FromArgb(255,?R,?G,?B);
????????????colorAnim.Duration?=?TimeSpan.FromSeconds(1);
????????????colorAnim.RepeatBehavior?=?new?RepeatBehavior(1);
????????????colorAnim.AutoReverse?=?false;
????????????Storyboard.SetTarget(colorAnim,?br);
????????????Storyboard.SetTargetProperty(colorAnim,?new?PropertyPath("Color"));
????????????storyboard.Children.Add(colorAnim);
????????????Resources.Add("colorsb",?storyboard);

????????????this.Loaded?+=?new?RoutedEventHandler(BackGorund_Loaded);
????????}
????} 創建ModelLocator ?? ?public?class?BackGroundModel?:?ModelLocator
????{
????????

????????private?static?readonly?BackGroundModel?_instance?=?new?BackGroundModel();

????????public?static?BackGroundModel?Instance?{?get?{?return?_instance;?}?}

????????static?BackGroundModel()
????????{

????????}
????????private?BackGroundModel()
????????????:?base()
????????{

????????}

????????private?byte?_R?=?(byte)0;
????????public?byte?R
????????{
????????????get?{?return?_R;?}
????????????set
????????????{
????????????????_R?=?value;
????????????????NotifyPropertyChanged("R");
????????????}
????????}

????????private?byte?_G?=?(byte)0;
????????public?byte?G
????????{
????????????get?{?return?_G;?}
????????????set
????????????{
????????????????_G?=?value;
????????????????NotifyPropertyChanged("G");
????????????}
????????}

????????private?byte?_B?=?(byte)0;
????????public?byte?B
????????{
????????????get?{?return?_B;?}
????????????set
????????????{
????????????????_B?=?value;
????????????????NotifyPropertyChanged("B");
????????????}
????????}

????}

控件Load時綁定屬性，通過模型來控制視圖

?? ? ? ?void?BackGorund_Loaded(object?sender,?RoutedEventArgs?e)
????????{
????????????this.DataContext?=?BackGroundModel.Instance;
????????????Binding?bindR?=?new?Binding("R");
????????????bindR.Mode?=?BindingMode.TwoWay;
????????????this.SetBinding(RProperty,?bindR);
????????????Binding?bindG?=?new?Binding("G");
????????????bindG.Mode?=?BindingMode.TwoWay;
????????????this.SetBinding(GProperty,?bindG);
????????????Binding?bindB?=?new?Binding("B");
????????????bindB.Mode?=?BindingMode.TwoWay;
????????????this.SetBinding(BProperty,?bindB);
????????}

?

提高效率

Shawn Wildermuth?寫了一個Code Snippets能幫我們快速的創建DependencyProperty屬性，具體用法與下載地址請訪問這里?。我自己寫了一個快速創建ModelLocator的Code Snippets，用法都是一樣，點擊這里?下載。 送上視頻 ：） ViewManagerP1.wmv 基于Cairngorm的Silverlight開發 - part2

轉載于:https://www.cnblogs.com/nasa/archive/2009/03/15/Cairngorm-Silverligh-part3.html

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