需要一个 VB.net Combobox 派生类来匹配模式或包含自动完成功能

是的，它可以在 VB.NET 中完成。我的想法过程相同，您可以尝试将您从 C# 发布的链接中的代码转换为 VB.NET，如前面的评论所建议的那样。但是，当我尝试这样做时，生成的 VB 无法编译。在修复了许多构建错误和一些语法错误之后，我向您展示了SuggestComboBox的VB版本及其使用方式。我发布此答案的唯一原因是因为从 C# 到 VB 的转换并不简单，并且源代码发布的许可证允许我这样做。

源

许可证

您需要通过窗体的代码隐藏添加控件，我在源代码中找不到设计器部分（责怪我缺乏 C# 知识）。

Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Drawing
Imports System.Linq
Imports System.Linq.Expressions
Imports System.Windows.Forms
Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        Dim testbox As New AutoCompleteComboBox.SuggestComboBox
        Me.Controls.Add(testbox)
        testbox.DataSource = New List(Of String) From {"Janean Mcgaha", "Tama Gaitan", "Jacque Tinnin", "Elvira Woolfolk", "Fransisca Owens", "Minnie Ardoin", _
        "Renay Bentler", "Joye Boyter", "Jaime Flannery", "Maryland Arai", "Walton Edelstein", "Nereida Storrs", _
        "Theron Zinn", "Katharyn Estrella", "Alline Dubin", "Edra Bhatti", "Willa Jeppson", "Chelsea Revel", _
        "Sonya Lowy", "Danelle Kapoor"}
    End Sub
End Class
Namespace AutoCompleteComboBox
    Public Class SuggestComboBox
        Inherits ComboBox
#Region "fields and properties"
        Private ReadOnly _suggLb As New ListBox() With {.Visible = False, .TabStop = False}
        Private ReadOnly _suggBindingList As New BindingList(Of String)()
        Private _propertySelector As Expression(Of Func(Of ObjectCollection, IEnumerable(Of String)))
        Private _propertySelectorCompiled As Func(Of ObjectCollection, IEnumerable(Of String))
        Private _filterRule As Expression(Of Func(Of String, String, Boolean))
        Private _filterRuleCompiled As Func(Of String, Boolean)
        Private _suggestListOrderRule As Expression(Of Func(Of String, String))
        Private _suggestListOrderRuleCompiled As Func(Of String, String)
        Public Property SuggestBoxHeight() As Integer
            Get
                Return _suggLb.Height
            End Get
            Set(value As Integer)
                If value > 0 Then
                    _suggLb.Height = value
                End If
            End Set
        End Property
        ''' <summary>
        ''' If the item-type of the ComboBox is not string,
        ''' you can set here which property should be used
        ''' </summary>
        Public Property PropertySelector() As Expression(Of Func(Of ObjectCollection, IEnumerable(Of String)))
            Get
                Return _propertySelector
            End Get
            Set(value As Expression(Of Func(Of ObjectCollection, IEnumerable(Of String))))
                If value Is Nothing Then
                    Return
                End If
                _propertySelector = value
                _propertySelectorCompiled = value.Compile()
            End Set
        End Property
        '''<summary>
        ''' Lambda-Expression to determine the suggested items
        ''' (as Expression here because simple lamda (func) is not serializable)
        ''' <para>default: case-insensitive contains search</para>
        ''' <para>1st string: list item</para>
        ''' <para>2nd string: typed text</para>
        '''</summary>
        Public Property FilterRule() As Expression(Of Func(Of String, String, Boolean))
            Get
                Return _filterRule
            End Get
            Set(value As Expression(Of Func(Of String, String, Boolean)))
                If value Is Nothing Then
                    Return
                End If
                _filterRule = value
                _filterRuleCompiled = Function(item) value.Compile()(item, Text)
            End Set
        End Property
        '''<summary>
        ''' Lambda-Expression to order the suggested items
        ''' (as Expression here because simple lamda (func) is not serializable)
        ''' <para>default: alphabetic ordering</para>
        '''</summary>
        Public Property SuggestListOrderRule() As Expression(Of Func(Of String, String))
            Get
                Return _suggestListOrderRule
            End Get
            Set(value As Expression(Of Func(Of String, String)))
                If value Is Nothing Then
                    Return
                End If
                _suggestListOrderRule = value
                _suggestListOrderRuleCompiled = value.Compile()
            End Set
        End Property
#End Region
        ''' <summary>
        ''' ctor
        ''' </summary>
        Public Sub New()
            ' set the standard rules:
            _filterRuleCompiled = Function(s) s.ToLower().Contains(Text.Trim().ToLower())
            _suggestListOrderRuleCompiled = Function(s) s
            _propertySelectorCompiled = Function(collection) collection.Cast(Of String)()
            _suggLb.DataSource = _suggBindingList
            AddHandler _suggLb.Click, AddressOf SuggLbOnClick
            AddHandler ParentChanged, AddressOf OnParentChanged
        End Sub
        ''' <summary>
        ''' the magic happens here ;-)
        ''' </summary>
        ''' <param name="e"></param>
        Protected Overrides Sub OnTextChanged(e As EventArgs)
            MyBase.OnTextChanged(e)
            If Not Focused Then
                Return
            End If
            _suggBindingList.Clear()
            _suggBindingList.RaiseListChangedEvents = False
            _propertySelectorCompiled(Items).Where(_filterRuleCompiled).OrderBy(_suggestListOrderRuleCompiled).ToList().ForEach(AddressOf _suggBindingList.Add)
            _suggBindingList.RaiseListChangedEvents = True
            _suggBindingList.ResetBindings()
            _suggLb.Visible = _suggBindingList.Any()
            If _suggBindingList.Count = 1 AndAlso _suggBindingList.[Single]().Length = Text.Trim().Length Then
                Text = _suggBindingList.[Single]()
                [Select](0, Text.Length)
                _suggLb.Visible = False
            End If
        End Sub
#Region "size and position of suggest box"
        ''' <summary>
        ''' suggest-ListBox is added to parent control
        ''' (in ctor parent isn't already assigned)
        ''' </summary>
        ''' <param name="sender"></param>
        ''' <param name="e"></param>
        Private Overloads Sub OnParentChanged(sender As Object, e As EventArgs)
            Parent.Controls.Add(_suggLb)
            Parent.Controls.SetChildIndex(_suggLb, 0)
            _suggLb.Top = Top + Height - 3
            _suggLb.Left = Left + 3
            _suggLb.Width = Width - 20
            _suggLb.Font = New Font("Segoe UI", 9)
        End Sub
        Protected Overrides Sub OnLocationChanged(e As EventArgs)
            MyBase.OnLocationChanged(e)
            _suggLb.Top = Top + Height - 3
            _suggLb.Left = Left + 3
        End Sub
        Protected Overrides Sub OnSizeChanged(e As EventArgs)
            MyBase.OnSizeChanged(e)
            _suggLb.Width = Width - 20
        End Sub
#End Region
#Region "visibility of suggest box"
        Protected Overrides Sub OnLostFocus(e As EventArgs)
            ' _suggLb can only getting focused by clicking (because TabStop is off)
            ' --> click-eventhandler 'SuggLbOnClick' is called
            If Not _suggLb.Focused Then
                HideSuggBox()
            End If
            MyBase.OnLostFocus(e)
        End Sub
        Private Sub SuggLbOnClick(sender As Object, eventArgs As EventArgs)
            Text = _suggLb.Text
            Focus()
        End Sub
        Private Sub HideSuggBox()
            _suggLb.Visible = False
        End Sub
        Protected Overrides Sub OnDropDown(e As EventArgs)
            HideSuggBox()
            MyBase.OnDropDown(e)
        End Sub
#End Region
#Region "keystroke events"
        ''' <summary>
        ''' if the suggest-ListBox is visible some keystrokes
        ''' should behave in a custom way
        ''' </summary>
        ''' <param name="e"></param>
        Protected Overrides Sub OnPreviewKeyDown(e As PreviewKeyDownEventArgs)
            If Not _suggLb.Visible Then
                MyBase.OnPreviewKeyDown(e)
                Return
            End If
            Select Case e.KeyCode
                Case Keys.Down
                    If _suggLb.SelectedIndex < _suggBindingList.Count - 1 Then
                        _suggLb.SelectedIndex += 1
                    End If
                    Return
                Case Keys.Up
                    If _suggLb.SelectedIndex > 0 Then
                        _suggLb.SelectedIndex -= 1
                    End If
                    Return
                Case Keys.Enter
                    Text = _suggLb.Text
                    [Select](0, Text.Length)
                    _suggLb.Visible = False
                    Return
                Case Keys.Escape
                    HideSuggBox()
                    Return
            End Select
            MyBase.OnPreviewKeyDown(e)
        End Sub
        Private Shared ReadOnly KeysToHandle As List(Of Keys) = New List(Of Keys) From {Keys.Down, Keys.Up, Keys.Enter, Keys.Escape}
        Protected Overrides Function ProcessCmdKey(ByRef msg As Message, keyData As Keys) As Boolean
            ' the keysstrokes of our interest should not be processed be base class:
            If _suggLb.Visible AndAlso KeysToHandle.Contains(keyData) Then
                Return True
            End If
            Return MyBase.ProcessCmdKey(msg, keyData)
        End Function
#End Region
    End Class
End Namespace