Model /ObservableCollection/ICollectionView
在上一篇讲了《[Silverlight入门系列]使用MVVM模式(1)：MVVM核心概念 》，今天讲一下集合Model。所谓集合Model就是给ItemsControl，如DataGrid，Combobox等绑定的集合数据模型。另外，通过定制ItemsControl的数据模板（DataTemplate），还可以控制集合对象中每一项的显示。实现很简单，但数据源集合对象必须继承IEnumerable接口，为了让目标属性与数据源集合的更新（不但包括元素的修改，还包括元素的增加和删除）保持同步，数据源集合还必须实现INotifyPropertyChanged接口和INotifyCollectionChanged接口。
ObservableCollection
在Silverlight中创建数据源集合可以使用内建的ObservableCollection类，因为ObservableCollection类既实现了INotifyPropertyChanged接口，又实现了INotifyCollectionChanged接口。使用ObservableCollection类不但可以实现Add、Remove、Clear和Insert操作，还可以触发PropertyChanged事件。
1 using
System.Collections.ObjectModel;
2 using
System.Collections;
3
4 public class MyModelCollection : ObservableCollection<MyModel>
5
{
6 public
MyModelCollection()
7
{
8
}
9
10 public
MyModelCollection(IEnumerable MyModels)
11
{
12 foreach (MyModel h in
MyModels)
13 this
.Add(h);
14
}
15
16 public void
AddRange(IEnumerable MyModels)
17
{
18 foreach (MyModel h in
MyModels)
19 this
.Add(h);
20
}
21
}
22
23 public class
MyModel
24
{
25 public int ModelID { get; set
; }
26 public string ModelName { get; set
; }
27
}
28
29 public class
MyViewModel
30
{
31 public MyModelCollection MyModelDataCollection { get; set
; }
32 public
MyViewModel(MyModelCollection modelCollection)
33
{
34 MyModelDataCollection =
modelCollection;
35
}
36 }
集合Model绑定到ItemControl也很简单：
1 private
MyViewModel viewModel;
2
3 public
MainPage()
4
{
5
InitializeComponent();
6
7 MyModel m1 = new MyModel() { ModelID = 1, ModelName = "abc"
};
8 MyModel m2 = new MyModel() { ModelID = 2, ModelName = "def"
};
9
10 viewModel = new MyViewModel(new MyModelCollection(new List<MyModel>
() { m1, m2 }));
11
12 this.DataContext =
viewModel;
13
14 this.dataGrid1.ItemsSource =
viewModel.MyModelDataCollection;
15 this.dataGrid1.AutoGenerateColumns = true
;
16
17 this.comboBox1.ItemsSource =
viewModel.MyModelDataCollection;
18 this.comboBox1.DisplayMemberPath = "ModelName"
;
19 this.comboBox1.SelectedValuePath = "ModelID"
;
20
21 this.comboBox1.SelectionChanged += new
SelectionChangedEventHandler(comboBox1_SelectionChanged);
22
}
23
24 void comboBox1_SelectionChanged(object
sender, SelectionChangedEventArgs e)
25
{
26 this.textBlock1.Text = "Selected value: " + this
.comboBox1.SelectedValue;
27 }
ICollectionView / PagedCollectionView
虽然上述的ObservableCollection很好用而且继承了INotifyPropertyChanged接口，有些时候我们需要对集合进行排序、过滤、分页等操作，这个时候就需要用ICollectionView接口，同样继承了INotifyPropertyChanged接口。ICollectionView接口在Silverlight下有个子类：PagedCollectionView，在WPF下有个子类：ListCollectionView.
PagedCollectionView例子:
C#:
1 public class
MyViewModel : INotifyPropertyChanged
2
{
3 public ICollectionView Customers { get; private set
; }
4
5 public MyViewModel( ObservableCollection<Customer>
customers )
6
{
7 //
Initialize the CollectionView for the underlying model
8 // and track the current selection.
9 Customers = new
PagedCollectionView( customers );
10 Customers.CurrentChanged +=
11 new
EventHandler( SelectedItemChanged );
12
}
13
14 private void SelectedItemChanged( object
sender, EventArgs e )
15
{
16 Customer current = Customers.CurrentItem as
Customer;
17
...
18
}
19 }
XAML:
1 <ListBox ItemsSource="{Binding Path=Customers}">
2 <ListBox.ItemTemplate>
3 <DataTemplate>
4 <StackPanel>
5 <TextBlock Text="{Binding Path=Name}"/>
6 StackPanel>
7 DataTemplate>
8 ListBox.ItemTemplate>
9 ListBox>
引用地址：
http://www.cnblogs.com/Mainz/archive/2011/05/04/2036680.html