Silverlight自定义控件系列 – TreeView (4) 缩进

接下来是缩进，没有缩进的Tree怎么看都不顺眼。

首先，定义节点深度Depth(注：回叫方法暂没有代码，以后要用到)：

1: /// <summary>

2: /// Using a DependencyProperty as the backing store for Depth. This enables animation, styling, binding, etc...

3: /// </summary>

4: public static readonly DependencyProperty DepthProperty =

5:  DependencyProperty.Register("Depth", typeof(int), typeof(FancyTreeViewItem),

6:  new PropertyMetadata(0, new PropertyChangedCallback(FancyTreeViewItem.OnDepthPropertyChanged))

7: );

8:

1: /// <summary>

2: /// Gets or sets the node depth level in tree

3: /// </summary>

4: public int Depth

5: {

6:  get { return (int)GetValue(DepthProperty); }

7:  set { SetValue(DepthProperty, value); }

8:}

9:

1: /// <summary>

2: /// Call back when Depth property has been changed

3: /// </summary>

4: /// <param name="o">The target object</param>

5: /// <param name="e">>The property changed event arrguments</param>

6: private static void OnDepthPropertyChanged(DependencyObject o, DependencyPropertyChangedEventArgs e)

7: {

8: 

9: }

10:

接下来就是写出计算节点在树中深度值的方法：

1: /// <summary>

2: /// For getting the item depth level

3: /// </summary>

4: /// <returns>The result depth level</returns>

5: private int GetDepthLevel()

6: {

7:  int depthLevel = 0;

8: FrameworkElement element = this;

9:

10:while (element.Parent != null)

11: {

12:  var parent = element.Parent as FancyTreeViewItem;

13:

14:  if (parent != null)

15: {

16: depthLevel++;

17:  ////depthLevel = parent.GetDepthLevel() + 1;

18: }

19:

20: element = element.Parent as FrameworkElement;

21: }

22:

23:  return depthLevel;

24: }

25:

绑定样式的时候把缩进量放进去，在public override void OnApplyTemplate()中添加：

1: if (this.Indent != null)

2: {

3:  this.Indent.Width = this.GetDepthLevel() * 20;

4: }

5:

最后把Boder的边框颜色去掉，运行看效果：





图4.1 带缩进的效果图