潜移默化学会WPF（企业经验篇）--全新替代掉VisualHelper功能的类，可视树泛型查找，功能强大 

  1   /// <summary>
  2         /// Finds a Child of a given item in the visual tree. 
  3         /// </summary>
  4         /// <param name="parent">A direct parent of the queried item.</param>
  5         /// <typeparam name="T">The type of the queried item.</typeparam>
  6         /// <param name="childName">x:Name or Name of child. </param>
  7         /// <returns>The first parent item that matches the submitted type parameter. 
  8         /// If not matching item can be found, 
  9         /// a null parent is being returned.</returns>
 10         public static T FindChild<T>(DependencyObject parent, string childName)
 11            where T : DependencyObject
 12         {
 13             // Confirm parent and childName are valid. 
 14             if (parent == null) return null;
 15 
 16             T foundChild = null;
 17 
 18             int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
 19             for (int i = 0; i < childrenCount; i++)
 20             {
 21                 var child = VisualTreeHelper.GetChild(parent, i);
 22                 // If the child is not of the request child type child
 23                 T childType = child as T;
 24                 if (childType == null)
 25                 {
 26                     // recursively drill down the tree
 27                     foundChild = FindChild<T>(child, childName);
 28 
 29                     // If the child is found, break so we do not overwrite the found child. 
 30                     if (foundChild != null) break;
 31                 }
 32                 else if (!string.IsNullOrEmpty(childName))
 33                 {
 34                     var frameworkElement = child as FrameworkElement;
 35                     // If the child's name is set for search
 36                     if (frameworkElement != null && frameworkElement.Name == childName)
 37                     {
 38                         // if the child's name is of the request name
 39                         foundChild = (T)child;
 40                         break;
 41                     }
 42                 }
 43                 else
 44                 {
 45                     // child element found.
 46                     foundChild = (T)child;
 47                     break;
 48                 }
 49             }
 50 
 51             return foundChild;
 52         }
 53 
 54         public DependencyObject FindChild(DependencyObject o, Type childType)
 55         {
 56             DependencyObject foundChild = null;
 57             if (o != null)
 58             {
 59                 int childrenCount = VisualTreeHelper.GetChildrenCount(o);
 60                 for (int i = 0; i < childrenCount; i++)
 61                 {
 62                     var child = VisualTreeHelper.GetChild(o, i);
 63                     if (child.GetType() != childType)
 64                     {
 65                         foundChild = FindChild(child, childType);
 66                     }
 67                     else
 68                     {
 69                         foundChild = child;
 70                         break;
 71                     }
 72                 }
 73             }
 74             return foundChild;
 75         }
 76 
 77         public static T FindVisualParent<T>(UIElement element) where T : UIElement
 78         {
 79             UIElement parent = element; while (parent != null)
 80             {
 81                 T correctlyTyped = parent as T; if (correctlyTyped != null)
 82                 {
 83                     return correctlyTyped;
 84                 }
 85                 parent = VisualTreeHelper.GetParent(parent) as UIElement;
 86             } return null;
 87         }
 88 
 89         public static T FindChild<T>(DependencyObject parent) where T : DependencyObject
 90         {
 91             if (parent == null) return null;
 92 
 93             T childElement = null; int childrenCount = VisualTreeHelper.GetChildrenCount(parent); for (int i = 0; i < childrenCount; i++)
 94             {
 95                 var child = VisualTreeHelper.GetChild(parent, i);
 96                 T childType = child as T; if (childType == null)
 97                 {
 98                     childElement = FindChild<T>(child); if (childElement != null) break;
 99                 }
100                 else
101                 {
102                     childElement = (T)child; break;
103                 }
104             } return childElement;
105         }

用法，你懂的

posted @ 2012-04-19 14:01  AYUI框架  阅读(886)  评论(0)  编辑  收藏  举报