Silverlight中根据绑定内容动态生成模板

     最近在做Silverlight项目时，需要根据绑定的内容动态生成不同的模板。如是在网上找了下，发现这个不错，如是把例子总结了下。代码和注释如下。

(1)ObservableObject.cs类

//具有<a href="/tag/tongzhi/" target="_blank" class="keywords">通知</a><a href="/tag/gongneng/" target="_blank" class="keywords">功能</a>的ObservableObject的类 //其实可以将NotifyPropertyChanged写在City中，但这样以类的形式写更具有扩展性 public class ObservableObject : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; protected void NotifyPropertyChanged(object sender,String propertyName) { if (PropertyChanged != null) PropertyChanged(sender,new PropertyChangedEventArgs(propertyName)); } }

(2)City.cs类

//实体City public class City : ObservableObject { private string _Name; private string _Country; //城市<a href="/tag/mingcheng/" target="_blank" class="keywords">名称</a> public string Name { get { return _Name; } set { if (_Name != value) { _Name = value; NotifyPropertyChanged(this,"Name"); } } } //国家<a href="/tag/mingcheng/" target="_blank" class="keywords">名称</a> public string Country { get { return _Country; } set { if (_Country != value) { _Country = value; NotifyPropertyChanged(this,"Country"); } } } }

（3）DataTemplateSelector.cs类

public abstract class DataTemplateSelector : ContentControl { public virtual DataTemplate SelectTemplate(object item,DependencyObject container) { return null; } //重写OnContentChanged<a href="/tag/fangfa/" target="_blank" class="keywords">方法</a> protected override void OnContentChanged(object oldContent,object newContent) { base.OnContentChanged(oldContent,newContent); ContentTemplate = SelectTemplate(newContent,this); } }

（4）CountryTemplateSelector.cs类

public class CountryTemplateSelector : DataTemplateSelector { //定义Brazil,Usa,England三个不同国家模板 public DataTemplate BrazilTemplate { get; set; } public DataTemplate UsaTemplate { get; set; } public DataTemplate EnglandTemplate { get; set; } //由城市实体-->实体所在国家-->所在国家的模板 public override DataTemplate SelectTemplate( object item,DependencyObject container) { City itemAux = item as City; if (itemAux != null) { if (itemAux.Country == "Brazil") return BrazilTemplate; if (itemAux.Country == "USA") return UsaTemplate; if (itemAux.Country == "England") return EnglandTemplate; } return base.SelectTemplate(item,container); } }

（5）Mainviewmodel.cs类

//Cites<a href="/tag/shuxing/" target="_blank" class="keywords">属性</a> public ObservableCollection<City> Cities { get; set; } //数据集 public Main<a href="/tag/viewmode/" target="_blank" class="keywords">viewmode</a>l() { Cities = new ObservableCollection<City>(); Cities.Add(new City { Country = "Brazil",Name = "São Paulo" }); Cities.Add(new City { Country = "Brazil",Name = "Curitiba" }); Cities.Add(new City { Country = "Brazil",Name = "Rio de Janeiro" }); Cities.Add(new City { Country = "Brazil",Name = "Salvador" }); Cities.Add(new City { Country = "Brazil",Name = "Recife" }); Cities.Add(new City { Country = "USA",Name = "San Francisco" }); Cities.Add(new City { Country = "USA",Name = "Los Angeles" }); Cities.Add(new City { Country = "USA",Name = "New York" }); Cities.Add(new City { Country = "USA",Name = "Chicago" }); Cities.Add(new City { Country = "USA",Name = "Houston" }); Cities.Add(new City { Country = "England",Name = "London" }); } }

（6）MainPage.xaml

<UserControl x:Class="DataTemplateSelector.MainPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:DataTemplateSelector" mc:Ig<a href="/tag/nor/" target="_blank" class="keywords">nor</a>able="d" d:DesignHeight="300" d:DesignWidth="400"> <Grid x:Name="LayoutRoot" Background="White"> <List<a href="/tag/Box/" target="_blank" class="keywords">Box</a> ItemsSource="{Binding Cities}" HorizontalContentAlignment="Stretch" x:Name="LB"> <List<a href="/tag/Box/" target="_blank" class="keywords">Box</a>.ItemTemplate> <DataTemplate> <local:CountryTemplateSelector Content="{Binding}"> <local:CountryTemplateSelector.BrazilTemplate> <DataTemplate> <Grid Background="Green"> <TextBlock Text="{Binding Name}"/> </Grid> </DataTemplate> </local:CountryTemplateSelector.BrazilTemplate> <local:CountryTemplateSelector.UsaTemplate> <DataTemplate> <Grid Background="Blue"> <TextBlock Text="{Binding Name}"/> </Grid> </DataTemplate> </local:CountryTemplateSelector.UsaTemplate> <local:CountryTemplateSelector.EnglandTemplate> <DataTemplate> <Grid Background="Red"> <TextBlock Text="{Binding Name}"/> </Grid> </DataTemplate> </local:CountryTemplateSelector.EnglandTemplate> </local:CountryTemplateSelector> </DataTemplate> </List<a href="/tag/Box/" target="_blank" class="keywords">Box</a>.ItemTemplate> </List<a href="/tag/Box/" target="_blank" class="keywords">Box</a>> </Grid> </UserControl>

(7)MainPage.cs

public partial class MainPage : UserControl { public MainPage() { InitializeComponent(); this.Loaded += new RoutedEventHandler(MainPage_Loaded); } //根据MainPage.xaml中List<a href="/tag/Box/" target="_blank" class="keywords">Box</a>已设置好的三个国家的模板，绑定之后所属三个不同城市的名字都会 //<a href="/tag/jiashang/" target="_blank" class="keywords">加上</a>不同国家的颜色了Brazil（Green）,Usa(Blue),England(Red) void MainPage_Loaded(object sender,RoutedEventArgs e) { LB.ItemsSource = new Main<a href="/tag/viewmode/" target="_blank" class="keywords">viewmode</a>l().Cities; } //总结：根据绑定的数据类容，动态选择不同的模板确实很有用，例如：我们要复用<a href="/tag/yige/" target="_blank" class="keywords">一个</a>控件，而控件<a href="/tag/neirong/" target="_blank" class="keywords">内容</a>可能完全不一样，使用这种<a href="/tag/fangfa/" target="_blank" class="keywords">方法</a>可以达到更具你要加载的<a href="/tag/neirong/" target="_blank" class="keywords">内容</a>来创建控件。 }

源码下载页面：http://download.csdn.net/source/2684599