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我正在尝试制作一个基于文本框控件的自定义控件。此文本框控件还包含一个按钮、列表框和弹出窗口。我尝试在类的 OnApplyTemplate 函数中为按钮的鼠标按下事件添加一个事件处理程序。当我逐步调试时，会调用 OnApplyTemplate 并添加事件处理程序代码。

我的问题是，当我单击按钮时，不会调用事件处理程序子 DropDownButton_MouseDown。

这是我的课：

Imports System.Windows.Controls.Primitives

<TemplatePart(Name:="PART_ControlBorder", Type:=GetType(Border))> _
<TemplatePart(Name:="PART_DropDownButton", Type:=GetType(Button))> _
<TemplatePart(Name:="PART_Popup", Type:=GetType(Popup))> _
<TemplatePart(Name:="PART_ListBox", Type:=GetType(ListBox))> _

Public Class AutoCompleteTextBox
    Inherits TextBox

#Region "DECLARATIONS"
    Private Mainborder As Border
    Private popup As Popup
    Private listBox As ListBox
    Private dropDownButton As Button

#End Region

#Region "METHODS"
    Private Sub PopupOpen()
        If popup IsNot Nothing And popup.IsOpen = False Then
            popup.IsOpen = True
        Else
            Return
        End If
    End Sub

    Private Sub DropDownButton_MouseDown(sender As Object, e As System.EventArgs)
        PopupOpen()
    End Sub
#End Region

#Region "APPLY TEMPLATE"
    Public Overrides Sub OnApplyTemplate()
        MyBase.OnApplyTemplate()

        If Me.Template IsNot Nothing Then
            Dim button__1 As Button = TryCast(Me.Template.FindName("PART_DropDownButton", Me), Button)
            If button__1 IsNot dropDownButton Then
                'First unhook existing handler
                If dropDownButton IsNot Nothing Then
                    RemoveHandler dropDownButton.MouseDown, AddressOf DropDownButton_MouseDown
                End If
                dropDownButton = button__1
                If dropDownButton IsNot Nothing Then
                    AddHandler dropDownButton.MouseDown, AddressOf DropDownButton_MouseDown
                End If
            End If
        End If
    End Sub
#End Region

#Region "CONSTRUCTOR"
    Sub New()
        DefaultStyleKeyProperty.OverrideMetadata(GetType(AutoCompleteTextBox), New FrameworkPropertyMetadata(GetType(AutoCompleteTextBox)))
    End Sub

#End Region

End Class

我在 Visual Studio 2012 中使用 wpf .net 4.5。这是我的名为 AutoCompleteTextBox 的自定义控件的 xaml，该控件在解决方案中的另一个项目中定义：

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:krisis="clr-namespace:Krisis.Controls;assembly=Krisis.Controls"
    Title="MainWindow" Height="350" Width="525">
    <Grid>
        <krisis:AutoCompleteTextBox SearchText="Bob" Width="200" MinHeight="35" FontSize="18" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>
</Window>

有人可以帮我连接这个事件处理程序，以便当我单击按钮时调用子 DropDownButton_MouseDown。

提前致谢

4

1 回答 1

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所以我将 OnApplyTemplate 更改为以下内容，现在它可以工作了：

Public Overrides Sub OnApplyTemplate()
    MyBase.OnApplyTemplate()

    '' if template is not nothing then initialize controls and wire up the event handlers
    If Me.Template IsNot Nothing Then

        InitializePopup()
        InitializeBorder()

        ''reset the handler for DropDownButton
        If DropDownButton IsNot Nothing Then
            RemoveHandler DropDownButton.Click, AddressOf DropDownButton_Click
        End If
        InitializeButton()
        If DropDownButton IsNot Nothing Then
            AddHandler DropDownButton.Click, AddressOf DropDownButton_Click
        End If

        ''reset handlers for listbox
        If ResultsListBox IsNot Nothing Then
            RemoveHandler ResultsListBox.PreviewMouseDown, AddressOf ResultListBox_PreviewMouseDown
            RemoveHandler ResultsListBox.KeyDown, AddressOf ResultListBox_KeyDown
        End If
        InitializeListbox()
        If ResultsListBox IsNot Nothing Then
            AddHandler ResultsListBox.PreviewMouseDown, AddressOf ResultListBox_PreviewMouseDown
            AddHandler ResultsListBox.KeyDown, AddressOf ResultListBox_KeyDown
        End If
    End If
End Sub

这是我写的上面使用的 INitializeControl sub 的示例：

Private Sub InitializeButton()
    If dropDownButton Is Nothing Then
        dropDownButton = TryCast(Me.Template.FindName("PART_DropDownButton", Me), Button)
    End If
End Sub
于 2013-04-17T01:49:49.683 回答