WPF。查找绑定到特定属性的控件

Posted 2023-02-23

【中文标题】WPF。查找绑定到特定属性的控件

【英文标题】：WPF. Find control that binds to specific property

【发布时间】：2011-04-26 22:37:35

【问题描述】：

关于如何实现给定属性名的方法，找到绑定到给定属性的控件（可能来自可视化树）的任何想法？

【参考方案1】：

试试这个。首先，将这个 DependencyObjectHelper 类复制粘贴到您的项目中。它有一个功能，可以让您获取给定对象中的所有 BindingObjects。

public static class DependencyObjectHelper

    public static List<BindingBase> GetBindingObjects(Object element)
    
        List<BindingBase> bindings = new List<BindingBase>();
        List<DependencyProperty> dpList = new List<DependencyProperty>();
        dpList.AddRange(DependencyObjectHelper.GetDependencyProperties(element));
        dpList.AddRange(DependencyObjectHelper.GetAttachedProperties(element));

        foreach (DependencyProperty dp in dpList)
        
            BindingBase b = BindingOperations.GetBindingBase(element as DependencyObject, dp);
            if (b != null)
            
                bindings.Add(b);
            
        

        return bindings;
    

    public static List<DependencyProperty> GetDependencyProperties(Object element)
    
        List<DependencyProperty> properties = new List<DependencyProperty>();
        MarkupObject markupObject = MarkupWriter.GetMarkupObjectFor(element);
        if (markupObject != null)
        
            foreach (MarkupProperty mp in markupObject.Properties)
            
                if (mp.DependencyProperty != null)
                
                    properties.Add(mp.DependencyProperty);
                
            
        

        return properties;
    

    public static List<DependencyProperty> GetAttachedProperties(Object element)
    
        List<DependencyProperty> attachedProperties = new List<DependencyProperty>();
        MarkupObject markupObject = MarkupWriter.GetMarkupObjectFor(element);
        if (markupObject != null)
        
            foreach (MarkupProperty mp in markupObject.Properties)
            
                if (mp.IsAttached)
                
                    attachedProperties.Add(mp.DependencyProperty);
                
            
        

        return attachedProperties;
    

然后，创建这个 GetBindingSourcesRecursive 函数。它递归地收集可视化树中的 DependencyObjects，其中至少有一个以给定属性名称为目标的 Binding 对象。

private void GetBindingSourcesRecursive(string propertyName, DependencyObject root, List<object> sources)

    List<BindingBase> bindings = DependencyObjectHelper.GetBindingObjects(root);
    Predicate<Binding> condition =
        (b) =>
        
            return (b.Path is PropertyPath) 
                && (((PropertyPath)b.Path).Path == propertyName)
                && (!sources.Contains(root));
        ;

    foreach (BindingBase bindingBase in bindings)
    
        if (bindingBase is Binding)
        
            if (condition(bindingBase as Binding))
                sources.Add(root);
        
        else if (bindingBase is MultiBinding)
        
            MultiBinding mb = bindingBase as MultiBinding;
            foreach (Binding b in mb.Bindings)
            
                if (condition(bindingBase as Binding))
                    sources.Add(root);
            
        
        else if (bindingBase is PriorityBinding)
        
            PriorityBinding pb = bindingBase as PriorityBinding;
            foreach (Binding b in pb.Bindings)
            
                if (condition(bindingBase as Binding))
                    sources.Add(root);
            
        
    

    int childrenCount = VisualTreeHelper.GetChildrenCount(root);
    if (childrenCount > 0)
    
        for (int i = 0; i < childrenCount; i++)
        
            DependencyObject child = VisualTreeHelper.GetChild(root, i);
            GetBindingSourcesRecursive(propertyName, child, sources);
        
    

然后，要使用它，只需调用 GetBindingsRecursive 并传入属性名称、根视觉对象（例如窗口）和包含结果的对象列表。

List<object> sources = new List<object>();
GetBindingSourcesRecursive("SomePropertyPath", this, sources);
sources.ForEach((o) => Console.WriteLine(o.ToString()));

希望这会有所帮助。

【参考方案2】：

我根据接受的 ASanch 答案创建了代码。此代码使用 LogicalTreeHelper，使其速度提高 6 倍（在简单窗口上查找具有特定绑定的控件时为 130 毫秒与 20 毫秒）。

另外我修复了 ASanch 代码中的一些错误（查看原始 "else if (bindingBase is MultiBinding)" 或 "else if (bindingBase is PriorityBinding)"）。

public static class DependencyObjectHelper

    /// <summary>
    /// Gets all dependency objects which has binding to specific property
    /// </summary>
    /// <param name="dependencyObject"></param>
    /// <param name="propertyName"></param>
    /// <returns></returns>
    public static IList<DependencyObject> GetDependencyObjectsWithBindingToProperty(DependencyObject dependencyObject, string propertyName)
    
        var list = new List<DependencyObject>();
        GetDependencyObjectsWithBindingToPropertyRecursive(propertyName, dependencyObject, list);

        return list;
    

    /// <summary>
    /// 
    /// </summary>
    /// <param name="propertyName"></param>
    /// <param name="dependencyObject"></param>
    /// <param name="sources"></param>
    /// <remarks>
    /// Based on ASanch answer on http://***.com/questions/3959421/wpf-find-control-that-binds-to-specific-property
    /// </remarks>>
    private static void GetDependencyObjectsWithBindingToPropertyRecursive(string propertyName, DependencyObject dependencyObject, ICollection<DependencyObject> sources)
    
        var dependencyProperties = new List<DependencyProperty>();
        dependencyProperties.AddRange(MarkupWriter.GetMarkupObjectFor(dependencyObject).Properties.Where(x => x.DependencyProperty != null).Select(x => x.DependencyProperty).ToList());
        dependencyProperties.AddRange(
            MarkupWriter.GetMarkupObjectFor(dependencyObject).Properties.Where(x => x.IsAttached && x.DependencyProperty != null).Select(x => x.DependencyProperty).ToList());

        var bindings = dependencyProperties.Select(x => BindingOperations.GetBindingBase(dependencyObject, x)).Where(x => x != null).ToList();

        Predicate<Binding> condition = binding => binding != null && binding.Path.Path == propertyName && !sources.Contains(dependencyObject);

        foreach (var bindingBase in bindings)
        
            if (bindingBase is Binding)
            
                if (condition(bindingBase as Binding))
                    sources.Add(dependencyObject);
            
            else if (bindingBase is MultiBinding)
            
                if (((MultiBinding)bindingBase).Bindings.Any(bindingBase2 => condition(bindingBase2 as Binding)))
                
                    sources.Add(dependencyObject);
                
            
            else if (bindingBase is PriorityBinding)
            
                if (((PriorityBinding)bindingBase).Bindings.Any(bindingBase2 => condition(bindingBase2 as Binding)))
                
                    sources.Add(dependencyObject);
                
            
        

        var children = LogicalTreeHelper.GetChildren(dependencyObject).OfType<DependencyObject>().ToList();
        if (children.Count == 0)
            return;

        foreach(var child in children)
        
            GetDependencyObjectsWithBindingToPropertyRecursive(propertyName, child, sources);
        
    

【讨论】：

这里的所有ToList 调用都是完全没有必要的。

不应该将论点 propertyName 真正称为 bindingPath 或类似的东西吗？只是略读代码，并没有真正运行它，但是按属性名称搜索应该只需要检查dependencyProperties 列表。