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 }
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