WPF中的TreeView入门

WPF中的TreeView入门

最近在用WPF做开发，项目进展的还算顺利，WPF总体来说还是比较方便的，其中变化最大的主要是Listview和Treeview控件，而且TreeView似乎在WPF是一个备受指责的控件，很多人说他不好用。其实我觉得是开发人员没有掌握好WPF中所传承的MVC思想。在View方面，WPF中的TreeView给了开发人员更大的灵活性，开发人可以非常简单定制每个Node乃至整棵树的外形。同时新的TreeView可以接受各种Collection作为ItemSource，非常灵活。只要简单地了解这些新加入的概念，开发起来就可以得心应手。

首先一个简单的Demo

如果这实现这个Demo呢？我们从MVC三个方面入手：

TreeView的View

在WPF的TreeView，你可以定制每个节点的显示方式，包括为一个节点添加多个图标，这些都只需要在XAML中配置，而不必留下复杂的C#代码。例如：

   1:     <TreeView Name="tvProperties" Width="250" Padding="0" Margin="0" BorderThickness="1">

   2:         <TreeView.ItemTemplate>

   3:             <HierarchicalDataTemplate DataType="{x:Type local:PropertyNodeItem}" ItemsSource="{Binding Path=Children}">

   4:                 <StackPanel Orientation="Horizontal">

   5:                     <Image VerticalAlignment="Center" Source="{Binding Icon}" Width="16" Height="16" Margin="0,0,2,2"></Image>

   6:                     <TextBlock VerticalAlignment="Center" Text="{Binding DisplayName}"></TextBlock>

   7:                     <Image VerticalAlignment="Center" Source="{Binding EditIcon}" Margin="2,0,0,0"></Image>

   8:                     <StackPanel.ToolTip>

   9:                         <TextBlock VerticalAlignment="Center" Text="{Binding Name}" TextWrapping="Wrap" MaxWidth="200" ></TextBlock>

  10:                     </StackPanel.ToolTip>

  11:                 </StackPanel>

  12:             </HierarchicalDataTemplate>

  13:         </TreeView.ItemTemplate>

  14:     </TreeView>

在这里我定义了一个简单的TreeView，每个节点对应的DataType是PropertyNodeItem（稍后，我会给出它的定义），每个节点的内容包括：

• ICON：每个节点的首先会显示一个ICON
• DisplayName：每个节点上的文字（这里的文字仅显示一个大概内容，详细内容会在ToolTip中显示）
• Editable ICON：如果一个节点是可以编辑的，我会在节点后面再显示一个Edit ICON
• ToolTip：当鼠标移动到上面时会显示，宽度200PX，自动换行。

 

TreeView的Model

这里就是刚才说讲到的PropertyNodeItem的定义

   1:     internal class PropertyNodeItem

   2:      {

   3:          public string Icon { get; set; }

   4:          public string EditIcon { get; set; }

   5:          public string DisplayName { get; set; }

   6:          public string Name { get; set; }

   7:                  

   8:          public List<PropertyNodeItem> Children { get; set; }

   9:          public PropertyNodeItem()

  10:          {

  11:              Children = new List<PropertyNodeItem>();

  12:          }      

  13:      }

其中Children里面保存的是子节点。在刚才的View里面，我们把HierarchicalDataTemplate的ItemSource定义为PropertyNodeItem的Children熟悉，这样只要Children不为空，TreeView就会继续渲染Children中的对象，并且递归下去。

 

TreeView的Controller

这里的Controller，我写在xaml.cs里面：

   1:      private void ShowTreeView()

   2:      {

   3:          List<PropertyNodeItem> itemList = new List<PropertyNodeItem>();

   4:          PropertyNodeItem node1 = new PropertyNodeItem()

   5:          {

   6:              DisplayName = "Node No.1",

   7:              Name = "This is the discription of Node1. This is a folder.",

   8:              Icon = FOLDER_ICON,

   9:          };

  10:   

  11:          PropertyNodeItem node1tag1 = new PropertyNodeItem()

  12:          {

  13:              DisplayName = "Tag No.1",

  14:              Name = "This is the discription of Tag 1. This is a tag.",

  15:              Icon = TAG_ICON,

  16:              EditIcon = EDITABLE_ICON

  17:          };

  18:          node1.Children.Add(node1tag1);

  19:   

  20:          PropertyNodeItem node1tag2 = new PropertyNodeItem()

  21:          {

  22:              DisplayName = "Tag No.2",

  23:              Name = "This is the discription of Tag 2. This is a tag.",

  24:              Icon = TAG_ICON,

  25:              EditIcon = EDITABLE_ICON

  26:          };

  27:          node1.Children.Add(node1tag2);

  28:          itemList.Add(node1);

  29:   

  30:          PropertyNodeItem node2 = new PropertyNodeItem()

  31:          {

  32:              DisplayName = "Node No.2",

  33:              Name = "This is the discription of Node 2. This is a folder.",

  34:              Icon = FOLDER_ICON,

  35:          };

  36:   

  37:          PropertyNodeItem node2tag3 = new PropertyNodeItem()

  38:          {

  39:              DisplayName = "Tag No.3",

  40:              Name = "This is the discription of Tag 3. This is a tag.",

  41:              Icon = TAG_ICON,

  42:              EditIcon = EDITABLE_ICON

  43:          };

  44:          node2.Children.Add(node2tag3);

  45:   

  46:          PropertyNodeItem node2tag4 = new PropertyNodeItem()

  47:          {

  48:              DisplayName = "Tag No.4",

  49:              Name = "This is the discription of Tag 4. This is a tag.",

  50:              Icon = TAG_ICON,

  51:              EditIcon = EDITABLE_ICON

  52:          };

  53:          node2.Children.Add(node2tag4);

  54:          itemList.Add(node2);

  55:   

  56:          this.tvProperties.ItemsSource = itemList;

  57:      }

以上的代码非常简单，这里就不详加解释了

标签: WPF, Treeview