我需要在WPF控件层次结构中搜索与给定名称或类型匹配的控件。我该怎么做呢?
当前回答
对代码的扩展。
增加了重载,以按类型、按类型和标准(谓词)查找一个子元素,查找符合标准的所有类型的子元素 FindChildren方法除了是DependencyObject的扩展方法外,还是一个迭代器 FindChildren还遍历逻辑子树。请参阅博客中链接的Josh Smith的文章。
来源: https://code.google.com/p/gishu-util/source/browse/#git%2FWPF%2FUtilities
解释性博客文章: http://madcoderspeak.blogspot.com/2010/04/wpf-find-child-control-of-specific-type.html
其他回答
下面是我的代码,通过类型来查找控件,同时控制我们进入层次结构的深度 (maxDepth == 0表示无限深)。
public static class FrameworkElementExtension
{
public static object[] FindControls(
this FrameworkElement f, Type childType, int maxDepth)
{
return RecursiveFindControls(f, childType, 1, maxDepth);
}
private static object[] RecursiveFindControls(
object o, Type childType, int depth, int maxDepth = 0)
{
List<object> list = new List<object>();
var attrs = o.GetType()
.GetCustomAttributes(typeof(ContentPropertyAttribute), true);
if (attrs != null && attrs.Length > 0)
{
string childrenProperty = (attrs[0] as ContentPropertyAttribute).Name;
foreach (var c in (IEnumerable)o.GetType()
.GetProperty(childrenProperty).GetValue(o, null))
{
if (c.GetType().FullName == childType.FullName)
list.Add(c);
if (maxDepth == 0 || depth < maxDepth)
list.AddRange(RecursiveFindControls(
c, childType, depth + 1, maxDepth));
}
}
return list.ToArray();
}
}
exciton80……我有一个问题,你的代码不递归通过用户控件。它击中了网格根并抛出了一个错误。我相信这能解决我的问题:
public static object[] FindControls(this FrameworkElement f, Type childType, int maxDepth)
{
return RecursiveFindControls(f, childType, 1, maxDepth);
}
private static object[] RecursiveFindControls(object o, Type childType, int depth, int maxDepth = 0)
{
List<object> list = new List<object>();
var attrs = o.GetType().GetCustomAttributes(typeof(ContentPropertyAttribute), true);
if (attrs != null && attrs.Length > 0)
{
string childrenProperty = (attrs[0] as ContentPropertyAttribute).Name;
if (String.Equals(childrenProperty, "Content") || String.Equals(childrenProperty, "Children"))
{
var collection = o.GetType().GetProperty(childrenProperty).GetValue(o, null);
if (collection is System.Windows.Controls.UIElementCollection) // snelson 6/6/11
{
foreach (var c in (IEnumerable)collection)
{
if (c.GetType().FullName == childType.FullName)
list.Add(c);
if (maxDepth == 0 || depth < maxDepth)
list.AddRange(RecursiveFindControls(
c, childType, depth + 1, maxDepth));
}
}
else if (collection != null && collection.GetType().BaseType.Name == "Panel") // snelson 6/6/11; added because was skipping control (e.g., System.Windows.Controls.Grid)
{
if (maxDepth == 0 || depth < maxDepth)
list.AddRange(RecursiveFindControls(
collection, childType, depth + 1, maxDepth));
}
}
}
return list.ToArray();
}
这将消除一些元素-您应该像这样扩展它,以支持更广泛的控件数组。简单的讨论,请看这里
/// <summary>
/// Helper methods for UI-related tasks.
/// </summary>
public static class UIHelper
{
/// <summary>
/// Finds a parent of a given item on the visual tree.
/// </summary>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="child">A direct or indirect child of the
/// queried item.</param>
/// <returns>The first parent item that matches the submitted
/// type parameter. If not matching item can be found, a null
/// reference is being returned.</returns>
public static T TryFindParent<T>(DependencyObject child)
where T : DependencyObject
{
//get parent item
DependencyObject parentObject = GetParentObject(child);
//we've reached the end of the tree
if (parentObject == null) return null;
//check if the parent matches the type we're looking for
T parent = parentObject as T;
if (parent != null)
{
return parent;
}
else
{
//use recursion to proceed with next level
return TryFindParent<T>(parentObject);
}
}
/// <summary>
/// This method is an alternative to WPF's
/// <see cref="VisualTreeHelper.GetParent"/> method, which also
/// supports content elements. Do note, that for content element,
/// this method falls back to the logical tree of the element!
/// </summary>
/// <param name="child">The item to be processed.</param>
/// <returns>The submitted item's parent, if available. Otherwise
/// null.</returns>
public static DependencyObject GetParentObject(DependencyObject child)
{
if (child == null) return null;
ContentElement contentElement = child as ContentElement;
if (contentElement != null)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if (parent != null) return parent;
FrameworkContentElement fce = contentElement as FrameworkContentElement;
return fce != null ? fce.Parent : null;
}
//if it's not a ContentElement, rely on VisualTreeHelper
return VisualTreeHelper.GetParent(child);
}
}
对代码的扩展。
增加了重载,以按类型、按类型和标准(谓词)查找一个子元素,查找符合标准的所有类型的子元素 FindChildren方法除了是DependencyObject的扩展方法外,还是一个迭代器 FindChildren还遍历逻辑子树。请参阅博客中链接的Josh Smith的文章。
来源: https://code.google.com/p/gishu-util/source/browse/#git%2FWPF%2FUtilities
解释性博客文章: http://madcoderspeak.blogspot.com/2010/04/wpf-find-child-control-of-specific-type.html
您还可以使用FrameworkElement.FindName(string)按名称查找元素。
考虑到:
<UserControl ...>
<TextBlock x:Name="myTextBlock" />
</UserControl>
在代码隐藏文件中,你可以这样写:
var myTextBlock = (TextBlock)this.FindName("myTextBlock");
当然,因为它是使用x:Name定义的,所以您可以只引用生成的字段,但是您可能希望动态而不是静态地查找它。
这种方法也可用于模板,其中命名项出现多次(每次使用模板一次)。
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