Silverlight Telerik控件学习：带CheckBox复选框的树形TreeView控件

在web开发中，带checkbox的tree是一个很有用的东东，比如权限选择、分类管理，如果不用sl，单纯用js+css实现是很复杂的，有了SL之后，就变得很轻松了

解决方案一：

利用Silvelright ToolKit(微软的开源项目)，项目地址http://silverlight.codeplex.com/

在线演示地址:http://silverlight.net/content/samples/sl4/toolkitcontrolsamples/run/default.html

解决方案二：

telerik公司的Rad for Silverlight商业控件(收费控件)

在线演示地址 http://demos.telerik.com/silverlight/

不管用哪一种方案，代码都是差不多的，为了实现数据绑定，先创建一个silverlight类库项目BusinessObject，定义数据项实体:

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Markup;

namespace BusinessObject
{
    /// <summary>
    /// 地区数据项
    /// </summary>
    [ContentProperty("Children")]//指示Children属性是 XAML 的Content内容属性
    public class PlaceItem : INotifyPropertyChanged
    {
        /// <summary>
        /// 构造函数
        /// </summary>
        public PlaceItem()
        {
            Children = new Collection<PlaceItem>();
            IsSelected = true;
        }

        /// <summary>
        /// 地区名称
        /// </summary>
        public string Name { get; set; }

        /// <summary>
        /// 地区描述
        /// </summary>
        public string Description { get; set; }

        /// <summary>
        /// 得到下级元素容器
        /// </summary>
        public Collection<PlaceItem> Children { get; private set; }

        /// <summary>
        /// 是否有子项
        /// </summary>
        public bool HasChild
        {
            get
            {
                return Children.Count > 0;
            }
        }

        /// <summary>
        /// 是否选中
        /// </summary>
        private bool? _isSelected;

        /// <summary>
        /// 该特性是否想要被安装
        /// </summary>
        public bool? IsSelected
        {
            get
            {
                return _isSelected;
            }
            set
            {
                if (value != _isSelected)
                {
                    _isSelected = value;
                    OnPropertyChanged("IsSelected");
                }
            }
        }

  
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        /// 属性改变时触发事件
        /// </summary>
        /// <param name="propertyName">Property that changed.</param>
        private void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (null != handler)
            {
                handler.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}

然后再定义一个 演示数据集合类:

using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Markup;

namespace BusinessObject
{
    /// <summary>
    /// 地区数据项
    /// </summary>
    [ContentProperty("Children")]//指示Children属性是 XAML 的Content内容属性
    public class PlaceItem : INotifyPropertyChanged
    {
        /// <summary>
        /// 构造函数
        /// </summary>
        public PlaceItem()
        {
            Children = new Collection<PlaceItem>();
            IsSelected = true;
        }

        /// <summary>
        /// 地区名称
        /// </summary>
        public string Name { get; set; }

        /// <summary>
        /// 地区描述
        /// </summary>
        public string Description { get; set; }

        /// <summary>
        /// 得到下级元素容器
        /// </summary>
        public Collection<PlaceItem> Children { get; private set; }

        /// <summary>
        /// 是否有子项
        /// </summary>
        public bool HasChild
        {
            get
            {
                return Children.Count > 0;
            }
        }

        /// <summary>
        /// 是否选中
        /// </summary>
        private bool? _isSelected;

        /// <summary>
        /// 该特性是否想要被安装
        /// </summary>
        public bool? IsSelected
        {
            get
            {
                return _isSelected;
            }
            set
            {
                if (value != _isSelected)
                {
                    _isSelected = value;
                    OnPropertyChanged("IsSelected");
                }
            }
        }

  
        public event PropertyChangedEventHandler PropertyChanged;

        /// <summary>
        /// 属性改变时触发事件
        /// </summary>
        /// <param name="propertyName">Property that changed.</param>
        private void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (null != handler)
            {
                handler.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }
}

好了，开始干正事儿了:

toolkit中的treeview用法

xaml部分

<UserControl x:Class="ToolKit.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"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400" 
    xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
    xmlns:toolkit="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Toolkit" 
    xmlns:local="clr-namespace:BusinessObject;assembly=BusinessObject"
    xmlns:common="clr-namespace:System.Windows;assembly=System.Windows.Controls">

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.Resources>
            <!--定义数据源-->
            <local:SampleData x:Key="SampleDataSource"></local:SampleData>
            
            <!--定义模板-->
            <common:HierarchicalDataTemplate x:Key="NodeTemplate"  ItemsSource="{Binding Children}">
                <StackPanel Orientation="Horizontal" ToolTipService.ToolTip="{Binding Description}">
                    <CheckBox
                        IsTabStop="False"                        
                        IsThreeState="{Binding HasChild}"
                        IsChecked="{Binding IsSelected, Mode=TwoWay}"
                        Click="ItemCheckbox_Click"
                        />
                    <ContentPresenter Content="{Binding Name}" />
                </StackPanel>
            </common:HierarchicalDataTemplate>
        </Grid.Resources>


        <sdk:TreeView  Name="treeView1" ItemTemplate="{StaticResource NodeTemplate}"
                ItemsSource="{Binding Source={StaticResource SampleDataSource}, Path=SamplePlaceItemCollection}" Margin="10" BorderThickness="0">
            <sdk:TreeView.ItemContainerStyle>
                <Style TargetType="sdk:TreeViewItem">
                    <!--默认全展开-->
                    <Setter Property="IsExpanded" Value="True"/> 
                </Style>
            </sdk:TreeView.ItemContainerStyle>
        </sdk:TreeView>
    </Grid>
</UserControl>

后端cs部分：

using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using BusinessObject;


namespace ToolKit
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            this.Loaded += new RoutedEventHandler(MainPage_Loaded);

            
        }

        void MainPage_Loaded(object sender, RoutedEventArgs e)
        {
            this.treeView1.ItemsSource = SampleData.SamplePlaceItemCollection;
            this.treeView1.ExpandAll();
            //var obj = this.treeView1.Items[1];
        }

        /// <summary>
        /// 点击节点时，选中子节点，同时设置父节点状态
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ItemCheckbox_Click(object sender, RoutedEventArgs e)
        {
            TreeViewItem item = GetParentTreeViewItem((DependencyObject)sender);
            if (item != null)
            {
                PlaceItem feature = item.DataContext as PlaceItem;
                if (feature != null)
                {
                    UpdateChildrenCheckedState(feature);
                    UpdateParentCheckedState(item);
                }
            }
        }


        /// <summary>
        /// 取得节点的父节点
        /// </summary>
        /// <param name="item"></param>
        /// <returns></returns>
        private static TreeViewItem GetParentTreeViewItem(DependencyObject item)
        {
            if (item != null)
            {
                DependencyObject parent = VisualTreeHelper.GetParent(item);
                TreeViewItem parentTreeViewItem = parent as TreeViewItem;
                return (parentTreeViewItem != null) ? parentTreeViewItem : GetParentTreeViewItem(parent);
            }
            return null;
        }


        /// <summary>
        /// 更新父节点的选中状态
        /// </summary>
        /// <param name="item"></param>
        private static void UpdateParentCheckedState(TreeViewItem item)
        {
            //取得父节点
            TreeViewItem parent = GetParentTreeViewItem(item);
            if (parent != null)
            {
                PlaceItem parentItem = parent.DataContext as PlaceItem;
                if (parentItem != null)
                {                   
                    bool? childrenCheckedState = parentItem.Children.First<PlaceItem>().IsSelected;
                    for (int i = 1; i < parentItem.Children.Count(); i++)
                    {
                        if (childrenCheckedState != parentItem.Children[i].IsSelected)
                        {
                            childrenCheckedState = null;
                            break;
                        }
                    }
                   
                    parentItem.IsSelected = childrenCheckedState;

                    //递归处理上级父节点
                    UpdateParentCheckedState(parent);
                }
            }
        }

        /// <summary>
        /// 更新子节点选中状态
        /// </summary>
        /// <param name="feature"></param>
        private static void UpdateChildrenCheckedState(PlaceItem feature)
        {
            if (feature.IsSelected.HasValue)
            {
                foreach (PlaceItem childFeature in feature.Children)
                {
                    childFeature.IsSelected = feature.IsSelected;
                    if (childFeature.Children.Count() > 0)
                    {
                        UpdateChildrenCheckedState(childFeature);
                    }
                }
            }
        }
    }
}

可以看到了，为了处理实现全选等功能，后端还是要写一些代码处理

telerik的treeview用法:

<UserControl x:Class="Telerik.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"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400" 
    xmlns:common="clr-namespace:BusinessObject;assembly=BusinessObject"
    xmlns:telerik="http://schemas.telerik.com/2008/xaml/presentation">

    <Grid x:Name="LayoutRoot" Background="White">
        
        <Grid.Resources>
            <common:SampleData x:Key="SampleDataSource"></common:SampleData>

            <!--数据节点模板-->
            <DataTemplate x:Key="NodeTemplate">
                <TextBlock Text="{Binding Name}" />
            </DataTemplate>

            <!--子节点模板-->
            <telerik:HierarchicalDataTemplate x:Key="ChildTemplate" ItemTemplate="{StaticResource NodeTemplate}"
          ItemsSource="{Binding Children}">
                <TextBlock Text="{Binding Name}" />
            </telerik:HierarchicalDataTemplate>

            <!--父节点模板-->
            <telerik:HierarchicalDataTemplate x:Key="ParentTemplate" ItemTemplate="{StaticResource ChildTemplate}"
          ItemsSource="{Binding Children}">
                <TextBlock Text="{Binding Name}" />
            </telerik:HierarchicalDataTemplate>
            
        </Grid.Resources>


        <telerik:RadTreeView
      ItemsSource="{Binding Source={StaticResource SampleDataSource}, Path=SamplePlaceItemCollection}"
      ItemTemplate="{StaticResource ParentTemplate}" SelectionMode="Extended" IsLineEnabled="True" ItemsOptionListType="CheckList"  IsOptionElementsEnabled="True"
				IsRootLinesEnabled="True" IsTriStateMode="True" Margin="10">
            <telerik:RadTreeView.ItemContainerStyle>
                <Style TargetType="telerik:RadTreeViewItem">
                    <!--默认全展开-->
                    <Setter Property="IsExpanded" Value="True"/>
                </Style>
            </telerik:RadTreeView.ItemContainerStyle>
        </telerik:RadTreeView>


       
    </Grid>
</UserControl>

后端代码：木有！--商业控件，就是靠谱，很多功能已经帮开发者实现了.

效果：

在线演示地址:http://img.24city.com/jimmy/sl4/controls/treeview.html

示例源代码下载：http://files.cnblogs.com/yjmyzz/TreeView_Silverlight.7z