silverlight combobox数据绑定

silverlight2.0正式版比较之前的beta版本来说又多了几个控件例:ComboBox, ProgressBar, 和 PasswordBox等.以下是个人在运用ComboBox的数据绑定过程中做了个人小结：

 xaml.

<UserControl x:Class="CheckBoxAllDataGrid.ComboBoxTest"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Width="400" Height="300" Loaded="UserControl_Loaded">
    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="30"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="100"/>
            <ColumnDefinition Width="Auto"/>
        </Grid.ColumnDefinitions>
        <ComboBox x:Name="CBox_City" Grid.Row="0" Grid.Column="0" Width="60" HorizontalAlignment="Left"></ComboBox>
        <ComboBox x:Name="CBox_Channel" Grid.Row="0" Grid.Column="1" Width="60" HorizontalAlignment="Left"></ComboBox>
    </Grid>
</UserControl>

 

 cs.

 

using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;

namespace CheckBoxAllDataGrid
{
    public partial class ComboBoxTest : UserControl
    {
        public ComboBoxTest()
        {
            InitializeComponent();
        }
        private void UserControl_Loaded(object sender, RoutedEventArgs e)
        {
            this.CBox_City.SelectionChanged += new SelectionChangedEventHandler(CBox_City_SelectionChanged);
            this.CBox_Channel.SelectionChanged += new SelectionChangedEventHandler(CBox_Channel_SelectionChanged);

            this.CBox_City.ItemsSource = CitySource();
            this.CBox_City.DisplayMemberPath = "name";
            this.CBox_City.UpdateLayout();
            this.CBox_City.SelectedIndex = 0;
        }
        //城市
        void CBox_City_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (this.CBox_City.SelectedItem != null)
            {
                var CitAlly = this.CBox_City.SelectedItem;
                int CityID = ((city)CitAlly).id;

                this.CBox_Channel.ItemsSource = (from a in ChannelSource() where a.cityid == CityID select a);
                this.CBox_Channel.DisplayMemberPath = "channelName";
                this.CBox_City.UpdateLayout();
                this.CBox_Channel.SelectedIndex = 0;
            }
        }
        //频道
        void CBox_Channel_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
                        
        }

        public List<city> CitySource()
        {
            List<city> cityinfo = new List<city>();
            cityinfo.Add(new city { id = 1, name = "北京" });
            cityinfo.Add(new city { id = 2, name = "福建" });
            return cityinfo;
        }

        public List<channel> ChannelSource()
        {
            List<channel> channelinfo = new List<channel>();
            channelinfo.Add(new channel { id = 11, channelName = "海淀区电视台", cityid = 1 });
            channelinfo.Add(new channel { id = 22, channelName = "朝阳区电视台", cityid = 1 });
            channelinfo.Add(new channel { id = 33, channelName = "福州市电视台", cityid = 2 });
            channelinfo.Add(new channel { id = 44, channelName = "厦门市电视台", cityid = 2 });

            return channelinfo;
        }

        public struct city
        {
            public int id { get; set; }
            public string name { get; set; }
        }

        public struct channel
        {
            public int id { get; set; }
            public string channelName { get; set; }
            public int cityid { get; set; }
        }
    }
}

 

注：如果在绑定的时候就给他指定SelectedIndex属性则在绑定后马上触发SelectionChanged事件

     所以在页面如果有两个或两个以上的连动(例:省份与城市 福建省(Cbox_pro) -- (Cbox_city) 福州，厦门)的控件

     且要求默认选定一个省份时绑定时应注意:

    1.在省份的绑定this.CBox_City.SelectedIndex = 0; 城市的绑定应写在省份的SelectionChanged事件里

    2.设置this.CBox_City.UpdateLayout();确保 UIElement 的所有子对象位置都正确地进行了布局更新