简单的通用TreeView(WPF)

      工作中要为很多类创建TreeView, 很多时候仅仅是因为要显示字段不同, 就得Ctrl+C、Ctrl+V复制一份几乎相同的代码, 这难免让人生厌, 于是希望像泛型集合的扩展方法那样, 可以在使用的时候灵活指定要显示哪个字段.

       下面的TreeView要实现这样的逻辑: 父项目 被勾选 或者 取消勾选, 那么它的所有子项目全部改成 被勾选 或者 取消勾选; 只有所有的子项目都被勾选时, 父项目才自发的改成被勾选

1. 创建基本的CommonTreeViewItemModel

       /// <summary>
       /// 通用的TreeViewItem模型, 仅包含最基础CheckBox(如果你觉得不好看, 在CommonTreeView.xaml中修改样式), 还包含一个 Tag(包含的对象)
       /// 业务逻辑: 父项目 被勾选 或者 取消勾选, 那么它的所有子项目全部改成 被勾选 或者 取消勾选; 只有所有的子项目都被勾选时, 父项目才自发的改成被勾选
       /// 所有的字段都改为protected, 方便继承修改
       /// </summary>
       public class CommonTreeViewItemModel : INotifyPropertyChanged
       {
   
           #region 属性
   
           public event PropertyChangedEventHandler PropertyChanged;
   
           protected object id;
           /// <summary>
           /// 唯一性Id
           /// </summary>
           public object Id
           {
               get { return id; }
               set { id = value; }
           }
   
           protected string caption;
           /// <summary>
           /// 标题
           /// </summary>
           public string Caption
           {
               get { return caption; }
               set { caption = value; if (PropertyChanged != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs("Caption")); }
           }
   
           protected bool isChecked;
           /// <summary>
           /// 是否被勾选
           /// </summary>
           public bool IsChecked
           {
               get { return isChecked; }
               set
               {
                   isChecked = value;
                   if (PropertyChanged != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs("IsChecked"));
                   SetIsCheckedByParent(value);
                   if (Parent != null) Parent.SetIsCheckedByChild(value);
               }
           }
   
           protected bool isExpanded;
           /// <summary>
           /// 是否被展开
           /// </summary>
           public bool IsExpanded
           {
               get { return isExpanded; }
               set { isExpanded = value; if (PropertyChanged != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs("IsExpanded")); }
           }
   
           protected CommonTreeViewItemModel parent;
           /// <summary>
           /// 父项目
           /// </summary>
           public CommonTreeViewItemModel Parent
           {
               get { return parent; }
               set { parent = value; }
           }
   
           protected List<CommonTreeViewItemModel> children = new List<CommonTreeViewItemModel>();
           /// <summary>
           /// 含有的子项目
           /// </summary>
           public List<CommonTreeViewItemModel> Children
           {
               get { return children; }
               set { children = value; }
           }
   
           /// <summary>
           /// 包含的对象
           /// </summary>
           public object Tag { get; set; }
   
           /// <summary>
           /// 包含对象的类型
           /// </summary>
           public Type TagType { get; set; }
           #endregion
   
           #region 业务逻辑, 如果你需要改成其他逻辑, 要修改的也就是这两行
   
           /// <summary>
           /// 子项目的isChecked改变了, 通知 是否要跟着改变 isChecked
           /// </summary>
           /// <param name="value"></param>
           public virtual void SetIsCheckedByChild(bool value)
           {
               if (this.isChecked == value)
               {
                   return;
               }
   
               bool isAllChildrenChecked = this.Children.All(c => c.IsChecked == true);
               this.isChecked = isAllChildrenChecked;
               if (PropertyChanged != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs("IsChecked"));
               if (Parent != null) Parent.SetIsCheckedByChild(value);
           }
   
           /// <summary>
           /// 自己的isChecked改变了, 所有子项目都要跟着改变
           /// </summary>
           /// <param name="value"></param>
           public virtual void SetIsCheckedByParent(bool value)
           {
               this.isChecked = value;
               if (PropertyChanged != null) PropertyChanged.Invoke(this, new PropertyChangedEventArgs("IsChecked"));
               foreach (var child in Children)
               {
                   child.SetIsCheckedByParent(value);
               }
           }
           #endregion
   
       }

2. 创建通用的 CommonTreeView, 这其中最关键的就是泛型方法SetItemsSourceData<TSource, TId>

       public partial class CommonTreeView : UserControl
       {
           public IList<CommonTreeViewItemModel> ItemsSourceData
           {
               get { return (IList<CommonTreeViewItemModel>)innerTree.ItemsSource; }
           }
   
           public CommonTreeView()
           {
               InitializeComponent();
           }
   
           /// <summary>
           /// 设置数据源, 以及各个字段
           /// </summary>
           /// <typeparam name="TSource">数据源类型</typeparam>
           /// <typeparam name="TId">主键类型</typeparam>
           /// <param name="itemsArray">数据源列表</param>
           /// <param name="captionSelector">指定显示为Caption的属性</param>
           /// <param name="idSelector">指定主键属性</param>
           /// <param name="parentIdSelector">指定父项目主键属性</param>
           public void SetItemsSourceData<TSource, TId>(IEnumerable<TSource> itemsArray, Func<TSource, string> captionSelector, Func<TSource, TId> idSelector, Func<TSource, TId> parentIdSelector)
                   where TId : IEquatable<TId>
           {
               var list = new List<CommonTreeViewItemModel>();
   
               foreach (var item in itemsArray.Where(a => object.Equals(default(TId), parentIdSelector(a))))
               {
                   var tvi = new CommonTreeViewItemModel();
                   tvi.Caption = captionSelector(item).ToString();
                   tvi.Id = idSelector(item);
                   tvi.Tag = item;
                   tvi.TagType = item.GetType();
                   list.Add(tvi);
                   RecursiveAddChildren(tvi, itemsArray, captionSelector, idSelector, parentIdSelector);
               }
   
               innerTree.ItemsSource = list;
               return;
           }
   
           /// <summary>
           /// 递归加载children
           /// </summary>
           /// <typeparam name="TSource"></typeparam>
           /// <typeparam name="TId"></typeparam>
           /// <param name="parent"></param>
           /// <param name="itemsArray"></param>
           /// <param name="captionSelector"></param>
           /// <param name="idSelector"></param>
           /// <param name="parentIdSelector"></param>
           /// <returns></returns>
           private CommonTreeViewItemModel RecursiveAddChildren<TSource, TId>(CommonTreeViewItemModel parent, IEnumerable<TSource> itemsArray, Func<TSource, string> captionSelector, Func<TSource, TId> idSelector, Func<TSource, TId> parentIdSelector)
           {
   
               foreach (var item in itemsArray.Where(a => parent.Id.Equals(parentIdSelector(a))))
               {
                   var tvi = new CommonTreeViewItemModel();
                   tvi.Caption = captionSelector(item);
                   tvi.Id = idSelector(item);
                   tvi.Tag = item;
                   tvi.TagType = item.GetType();
                   tvi.Parent = parent;
                   parent.Children.Add(tvi);
                   RecursiveAddChildren(tvi, itemsArray, captionSelector, idSelector, parentIdSelector);
               }
               return parent;
           }

3. CommonTreeView 对应的xaml

   <UserControl x:Class="WPFCommonTreeView.CommonTreeView"
                xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
                xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
                xmlns:local="clr-namespace:WPFCommonTreeView"
                mc:Ignorable="d"
                d:DesignHeight="300" d:DesignWidth="300">
       <Grid>
           <TreeView Name="innerTree">
               <TreeView.ItemContainerStyle>
                   <Style TargetType="TreeViewItem">
                       <Setter Property="IsExpanded" Value="{Binding IsExpanded, Mode=TwoWay}"></Setter>
                   </Style>
               </TreeView.ItemContainerStyle>
               <TreeView.ItemTemplate>
                   <HierarchicalDataTemplate DataType="{x:Type local:CommonTreeViewItemModel}"  ItemsSource="{Binding Children}">
                       <CheckBox   FontSize="14" FontFamily="微软雅黑" Tag="{Binding Children}" IsChecked="{Binding IsChecked, Mode=TwoWay}" Content="{Binding Caption}" />
                   </HierarchicalDataTemplate>
               </TreeView.ItemTemplate>
           </TreeView>
       </Grid>
   </UserControl>

4. 演示效果

   

 

        实例代码下载

        后记: 说实在的, 这个通用TreeView其实一点也不通用, 简单倒是真的, 主要原因是实际业务中TreeView的层次和逻辑千差万别, 就当自己的一点尝试吧.

       

         转载请注明出处: http://www.cnblogs.com/zhouandke/p/6201064.html