我怎样才能找到名称或类型的WPF控件？ [英] How can I find WPF controls by name or type?

问题描述

我需要搜索WPF控件层次结构，以查找与给定名称或类型匹配的控件。我怎样才能做到这一点？

解决方案

我将John Myczek和Tri Q的算法结合使用，创建一个findChild算法可以在任何父母上使用。请记住，向下递归搜索树可能是一个漫长的过程。我只在WPF应用程序中进行了特别检查，请对可能发现的任何错误进行评论，我将更正我的代码。

WPF Snoop 是一个有用的工具，可以查看可视化树 - 我强烈建议在测试或使用此算法检查您的工作时使用它。 Tri Q的算法有一个小错误在找到孩子之后，如果childrenCount> 1，我们再次迭代，我们可以覆盖正确找到的孩子。因此，我在代码中添加了一个 if（foundChild！= null）break; 来处理这个情况。

  ///< summary> 
 ///查找可视树中给定项的子项。 
 ///< / summary> 
 ///< param name =parent>被查询的项目的直接父母< / param> 
 ///< typeparam name =T>查询项目的类型< / typeparam> 
 ///< param name =childName> x：小孩的姓名或名称。 < / PARAM> 
 ///< returns>与提交的类型参数相匹配的第一个父项。 
 ///如果找不到匹配的项目，则返回
 ///空的父项。< / returns> 
 public static T FindChild< T>（DependencyObject parent，string childName）
其中T：DependencyObject 
 {
 //确认parent和childName是有效的。 
 if（parent == null）return null; 
 
 T foundChild = null; 
 
 int childrenCount = VisualTreeHelper.GetChildrenCount（parent）; 
 for（int i = 0; i< childrenCount; i ++）
 {
 var child = VisualTreeHelper.GetChild（parent，i）; 
 //如果孩子不是请求孩子类型的孩子
 T childType =孩子为T; 
 if（childType == null）
 {
 //递归地向下钻取树
 foundChild = FindChild< T>（child，childName）; 
 
 //如果找到孩子，请打破，这样我们就不会覆盖找到的孩子。 
 if（foundChild！= null）break; 
 
 else if（！string.IsNullOrEmpty（childName））
 {
 var frameworkElement = child作为FrameworkElement; 
 //如果孩子的名字设置为search 
 if（frameworkElement！= null&& frameworkElement.Name == childName）
 {
 //如果孩子的名字是请求名称
 foundChild =（T）child; 
 break; 
} 
} 
 else 
 {
 //找到子元素。 
 foundChild =（T）child; 
 break; 
} 
} 
 
 return foundChild; 
 
 $ / code> 

像这样调用：



  TextBox foundTextBox = 
 UIHelper.FindChild< TextBox>（Application.Current.MainWindow，myTextBoxName）; 
  

Note Application.Current.MainWindow 可以任何父窗口。


I need to search a WPF control hierarchy for controls that match a given name or type. How can I do this?

解决方案

I combined the template format used by John Myczek and Tri Q's algorithm above to create a findChild Algorithm that can be used on any parent. Keep in mind that recursively searching a tree downwards could be a lengthy process. I've only spot-checked this on a WPF application, please comment on any errors you might find and I'll correct my code.

WPF Snoop is a useful tool in looking at the visual tree - I'd strongly recommend using it while testing or using this algorithm to check your work.

There is a small error in Tri Q's Algorithm. After the child is found, if childrenCount is > 1 and we iterate again we can overwrite the properly found child. Therefore I added a if (foundChild != null) break; into my code to deal with this condition.

/// <summary>
/// Finds a Child of a given item in the visual tree. 
/// </summary>
/// <param name="parent">A direct parent of the queried item.</param>
/// <typeparam name="T">The type of the queried item.</typeparam>
/// <param name="childName">x:Name or Name of child. </param>
/// <returns>The first parent item that matches the submitted type parameter. 
/// If not matching item can be found, 
/// a null parent is being returned.</returns>
public static T FindChild<T>(DependencyObject parent, string childName)
   where T : DependencyObject
{    
  // Confirm parent and childName are valid. 
  if (parent == null) return null;

  T foundChild = null;

  int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
  for (int i = 0; i < childrenCount; i++)
  {
    var child = VisualTreeHelper.GetChild(parent, i);
    // If the child is not of the request child type child
    T childType = child as T;
    if (childType == null)
    {
      // recursively drill down the tree
      foundChild = FindChild<T>(child, childName);

      // If the child is found, break so we do not overwrite the found child. 
      if (foundChild != null) break;
    }
    else if (!string.IsNullOrEmpty(childName))
    {
      var frameworkElement = child as FrameworkElement;
      // If the child's name is set for search
      if (frameworkElement != null && frameworkElement.Name == childName)
      {
        // if the child's name is of the request name
        foundChild = (T)child;
        break;
      }
    }
    else
    {
      // child element found.
      foundChild = (T)child;
      break;
    }
  }

  return foundChild;
}

Call it like this:

TextBox foundTextBox = 
   UIHelper.FindChild<TextBox>(Application.Current.MainWindow, "myTextBoxName");

Note Application.Current.MainWindow can be any parent window.

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