c# - Wpf 按标签和类型查找所有控件

Question

我正在尝试按类型和标记名称检索所有元素。我已经找到了一些例子:

How can I find WPF controls by name or type?

https://stackoverflow.com/a/978352/7444801

我尝试修改其中一些示例，但它们从未给我想要的结果。

所需方法的示例:

public static Collection<T> FindAll<T>(DependencyObject parent, string childName)
where T : DependencyObject
{ 
//code that gives me the collection 
}

示例所需的标记对象:

<Ellipse  Tag="tagname" Fill="Blue"  Width="25" Height="25" />
<Ellipse  Tag="tagname" Fill="Blue"  Width="25" Height="25" />
<Ellipse  Tag="tagname" Fill="Blue"  Width="25" Height="25" />

我试过的方法:

public static Collection<T> FindAll<T>(DependencyObject parent, string childName)
where T : DependencyObject
    {
        Collection<T> result=null;

        Boolean b = true;
        int c = 0;
        while (b)
        {
            T obj = FindChild<T>(parent, childName, c,-1);
            if (obj == null) b = false;
            else
            {
                if(result == null) result = new Collection<T>();
                result.Add(obj);
            }
            c++;
        }
        return result;
    }`
      `     /**
      * Param c = count of desired object
     * Param indchild= keeps cound (give negative for calling function)
     * */
    public static T FindChild<T>(DependencyObject parent, string childName,int c, int indchild)
where T : DependencyObject
    {
        // Confirm parent and childName are valid. 
        if (parent == null) return null;

        T foundChild = null;

        int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
       if(indchild<=-1)indchild = 0;


        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,c,indchild);

                // 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.Tag!=null && ((String)frameworkElement.Tag).Equals(childName))
                {
                    // if the child's name is of the request name

                    if (c == indchild) { 
                    foundChild = (T)child;
                    break;
                   }
                    indchild++;
                }
            }
        }

        return foundChild;
    }

Answer 1

您可以使用以下 FindVisualChildren 方法:

Find all controls in WPF Window by type

...并简单地过滤结果:

string tagName = "tagname";
IEnumerable<Ellipse> elements = FindVisualChildren<Ellipse>(this).Where(x => x.Tag != null && x.Tag.ToString() == tagName);