WPF 应用Visual tree递归查找通用类的控件

最近的一个项目用基类的Template来包装窗体，新建的窗体里的一个按钮需要调用程序里的另外一个窗体，显示时需要把这个窗体加到mainWindow里的DocumentContainer（syncfusion的类库）里去，但在template里却不能直接得到主窗口的DocumentContainer，试了很多方法例如template里传值但太过复杂，google了一下，终于在stack overflow网站里找到了答案，他是用visual tree查找child控件，而我是查找parent控件，思路都是一样。方程是用generic写的，也就是你可以得到任意类型的控件。

 

 

程序如下： 

 

 

    ''' <summary>

    ''' Finds a Child of a given item in the visual tree.

    ''' </summary>

    ''' <typeparam name="T">The type of the queried item.</typeparam>

    ''' <param name="root">A direct root of the queried item.</param>

    ''' <param name="parentName">name of parent control want to search</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>

    ''' <remarks></remarks>

    ''' <writtenby name="" date="2011/02/05"></writtenby>

    Private Shared Function FindParent(Of T As DependencyObject)(ByVal root As DependencyObject, ByVal parentName As String) As DependencyObject

 

        Dim foundParent As T = Nothing

 

        If root Is Nothing Then

            Return foundParent

        Else

 

            Dim parent = VisualTreeHelper.GetParent(root)

            Dim frameworkElement As FrameworkElement = parent

 

            If frameworkElement IsNot Nothing AndAlso frameworkElement.Name = parentName Then

                foundParent = parent

 

            Else

                'recursively drill up the tree

                foundParent = FindParent(Of T)(parent, parentName)

            End If

        End If

 

        Return foundParent

 

    End Function

调用方法：

 

 

Dim objDependency As DependencyObject = CType(Me, DependencyObject)

 

 

Dim objDocumentContainer = FindParent(Of DependencyObject)(objDependency, "objDocumentContainer")

另外附图是visual tree的示意图，功能很强大，用的好的话帮助很大。