SliverLight使用ObservableCollection和INotifyPropertyChanged绑定数据

      ObservableCollection是动态的数据集合，当该集合增加、删除或者集合被刷新时，INotifyPropertyChanged会给客户端提供PropertyChanged的通知。

      在silverlight中，创建数据源集合可以使用ObservableCollection类，ObservableCollection实现了INotifyPropertyChanged、INotifyCollectionChanged，可以触发PropertyChanged事件。

      INotifyPropertyChanged的作用就是向客户端发出某一个属性值发生更改的通知。

      下面将创建一个简单的slverlight应用程序，用DataGrid来呈现Name和Score，另外有一Chart来呈现同样的数据，两者的数据源都是相同的ObservableCollection对象。最后创建一timer来随机地为ObservableCollection增加一行或者为某人更改Score。

      下面定义一个数据实体对象。

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.ComponentModel;

namespace SLObservableCollection
{
    public class User : INotifyPropertyChanged
    {
        #region Property
        private string name;
        public string Name
        {
            get { return name; }
            set
            {
                if (value != name)
                {
                    name = value;
                    onPropertyChanged(this, "Name");
                }
            }
        }


        private long score;
        public long Score
        {
            get { return score; }
            set
            {
                if (score != value)
                {
                    score = value;
                    onPropertyChanged(this, "Score");
                }
            }
        }
        #endregion

        #region INotifyPropertyChanged Members
        public event PropertyChangedEventHandler PropertyChanged;
        private void onPropertyChanged(object sender, string propertyName)
        {
            if (this.PropertyChanged != null)
            {
                PropertyChanged(sender, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion
    }
}

定义数据集合：

        ObservableCollection<User> GetUserCollection()
        {
            ObservableCollection<User> rVal = new ObservableCollection<User>();
            rVal.Add(new User { Name = "Tom", Score = 2 });
            rVal.Add(new User { Name = "ruth", Score = 3 });
            rVal.Add(new User { Name = "sunfishlu", Score = 4 });
            rVal.Add(new User { Name = "walle", Score = 5 });
            rVal.Add(new User { Name = "john", Score = 6 });

            return rVal;
        }

XAML布局和绑定：

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="300" />
        </Grid.RowDefinitions>
        <sdk:DataGrid x:Name="dataGrid" Grid.Row="0">
        </sdk:DataGrid>

        <charting:Chart x:Name="chartControl" Grid.Row="1" Title="Live Chart">
            <charting:Chart.Series>
                <charting:ColumnSeries DependentValueBinding="{Binding Score}"
                                       IndependentValueBinding="{Binding Name}" />
            </charting:Chart.Series>
        </charting:Chart>
    </Grid>

最后我们在构造器中绑定数据到datagrid和chart：

        public MainPage()
        {
            InitializeComponent();

            users = GetUserCollection();
            this.dataGrid.ItemsSource = users;
            ((DynamicSingleSeriesWithAxes)this.chartControl.Series[0]).ItemsSource = users;
            timer = new Timer(timerFired, null, 10000, 2000);
        }

效果图如下：

 

代码下载