我正在寻找一种方法,通过它们的类型在窗口上找到所有控件,
例如:找到所有的文本框,找到所有实现特定界面的控件等。
我正在寻找一种方法,通过它们的类型在窗口上找到所有控件,
例如:找到所有的文本框,找到所有实现特定界面的控件等。
当前回答
要获得特定类型的所有子元素的列表,您可以使用:
private static IEnumerable<DependencyObject> FindInVisualTreeDown(DependencyObject obj, Type type)
{
if (obj != null)
{
if (obj.GetType() == type)
{
yield return obj;
}
for (var i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
{
foreach (var child in FindInVisualTreeDown(VisualTreeHelper.GetChild(obj, i), type))
{
if (child != null)
{
yield return child;
}
}
}
}
yield break;
}
其他回答
@Bryce,回答得很好。
VB。净版:
Public Shared Iterator Function FindVisualChildren(Of T As DependencyObject)(depObj As DependencyObject) As IEnumerable(Of T)
If depObj IsNot Nothing Then
For i As Integer = 0 To VisualTreeHelper.GetChildrenCount(depObj) - 1
Dim child As DependencyObject = VisualTreeHelper.GetChild(depObj, i)
If child IsNot Nothing AndAlso TypeOf child Is T Then
Yield DirectCast(child, T)
End If
For Each childOfChild As T In FindVisualChildren(Of T)(child)
Yield childOfChild
Next
Next
End If
End Function
用法(这将禁用窗口中的所有文本框):
For Each tb As TextBox In FindVisualChildren(Of TextBox)(Me)
tb.IsEnabled = False
Next
这是最简单的方法:
IEnumerable<myType> collection = control.Children.OfType<myType>();
其中控件是窗口的根元素。
编辑-正如评论中指出的那样。这只是一个层次的深度。查看一个更深入的选项的公认答案。
I wanted to add a comment but I have less than 50 pts so I can only "Answer". Be aware that if you use the "VisualTreeHelper" method to retrieve XAML "TextBlock" objects then it will also grab XAML "Button" objects. If you re-initialize the "TextBlock" object by writing to the Textblock.Text parameter then you will no longer be able to change the Button text using the Button.Content parameter. The Button will permanently show the text written to it from the Textblock.Text write action (from when it was retrieved --
foreach (TextBlock tb in FindVisualChildren<TextBlock>(window))
{
// do something with tb here
tb.Text = ""; //this will overwrite Button.Content and render the
//Button.Content{set} permanently disabled.
}
要解决这个问题,您可以尝试使用XAML“文本框”并添加方法(或事件)来模拟XAMAL按钮。XAML“TextBox”不是通过搜索“TextBlock”收集的。
对于这个和更多的用例,你可以添加流动扩展方法到你的库:
public static List<DependencyObject> FindAllChildren(this DependencyObject dpo, Predicate<DependencyObject> predicate)
{
var results = new List<DependencyObject>();
if (predicate == null)
return results;
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(dpo); i++)
{
var child = VisualTreeHelper.GetChild(dpo, i);
if (predicate(child))
results.Add(child);
var subChildren = child.FindAllChildren(predicate);
results.AddRange(subChildren);
}
return results;
}
举个例子:
var children = dpObject.FindAllChildren(child => child is TextBox);
我的c++ /CLI版本
template < class T, class U >
bool Isinst(U u)
{
return dynamic_cast< T >(u) != nullptr;
}
template <typename T>
T FindVisualChildByType(Windows::UI::Xaml::DependencyObject^ element, Platform::String^ name)
{
if (Isinst<T>(element) && dynamic_cast<Windows::UI::Xaml::FrameworkElement^>(element)->Name == name)
{
return dynamic_cast<T>(element);
}
int childcount = Windows::UI::Xaml::Media::VisualTreeHelper::GetChildrenCount(element);
for (int i = 0; i < childcount; ++i)
{
auto childElement = FindVisualChildByType<T>(Windows::UI::Xaml::Media::VisualTreeHelper::GetChild(element, i), name);
if (childElement != nullptr)
{
return childElement;
}
}
return nullptr;
};