麻烦看下，代码哪里有问题。

[eaqpi]

multicolumnComboBox的代码，抄的，原来的c的，改了vb，完全没有什么效果啊。

Imports System
Imports System.Windows.Forms
Imports System.Collections
Imports System.Collections.ObjectModel
Imports System.Drawing
Imports System.Globalization

Public Class MultiColumnComboBox
    Inherits System.Windows.Forms.ComboBox
    Private _AutoComplete As Boolean
    Private _AutoDropdown As Boolean
    Private _BackColorEven As Color = Color.White
    Private _BackColorOdd As Color = Color.White
    Private _ColumnNameString As String = ""
    Private _ColumnWidthDefault As Integer = 75
    Private _ColumnWidthString As String = ""
    Private _LinkedColumnIndex As Int32
    Private _LinkedTextBox As System.Windows.Forms.TextBox
    Private _TotalWidth As Int32
    Private _ValueMemberColumnIndex As Int32

    Private _ColumnNames As New Collection(Of String)
    Private _ColumnWidths As New Collection(Of Int32)

    Public Sub MultiColumnComboBox()
        DrawMode = DrawMode.OwnerDrawVariable
        ContextMenu = New ContextMenu()
    End Sub

    Public Event OpenSearchForm As System.EventHandler

    Public Property AutoComplete() As Boolean
        Get
            Return _AutoComplete
        End Get
        Set(ByVal value As Boolean)
            _AutoComplete = value
        End Set
    End Property



    Public Property AutoDropdown As Boolean
        Get
            Return _AutoDropdown
        End Get
        Set(ByVal value As Boolean)
            _AutoDropdown = value
        End Set
    End Property
    Public Property BackColorEven As Color
        Get
            Return _BackColorEven
        End Get
        Set(ByVal value As Color)
            _BackColorEven = value
        End Set
    End Property
    Public Property BackColorOdd As Color
        Get
            Return _BackColorOdd
        End Get
        Set(ByVal value As Color)
            _BackColorOdd = value
        End Set
    End Property
    Public ReadOnly Property ColumnNameCollection As Collection(Of String)
        Get
            Return _ColumnNames
        End Get
    End Property

  
   

[eaqpi]

 Public ReadOnly Property ColumnWidthCollection As Collection(Of Int32)
        Get
            Return _ColumnWidths
        End Get
    End Property
    Public Property ColumnNames As String
        Get
            Return _ColumnNameString
        End Get
        Set(ByVal value As String)
            If Not Convert.ToBoolean(value.Trim().Length) Then
                _ColumnNameString = ""
            ElseIf value IsNot Nothing Then
                Dim delimiterChars() As Char = {",", ";", ":"}
                Dim columnNames = value.Split(delimiterChars)
                If Not DesignMode Then
                    _ColumnNames.Clear()
                End If
                For Each s As String In columnNames
                    If Convert.ToBoolean(s.Trim().Length) Then
                        If Not DesignMode Then
                            _ColumnNames.Add(s.Trim())
                        End If
                    Else
                        Throw New NotSupportedException("Column names can not be blank")
                    End If
                Next
                _ColumnNameString = value
            End If
        End Set
    End Property
    Public Property columnWidthDefault As Int32
        Get
            Return _ColumnWidthDefault
        End Get
        Set(ByVal value As Int32)
            _ColumnWidthDefault = value
        End Set
    End Property
    Public Property ColumnWidths As String
        Get
            Return _ColumnWidthString
        End Get
        Set(ByVal value As String)
            If Not Convert.ToBoolean(value.Trim().Length) Then
                _ColumnWidthString = ""
            ElseIf value IsNot Nothing Then
                Dim delimiterChars() As Char = {",", ";", ":"}
                Dim columnWdiths = value.Split(delimiterChars)
                Dim invalidValue As String = ""
                Dim invalidIndex As Int32 = -1
                Dim idx As Int32 = 1
                Dim intValue As Int32
                For Each s As String In ColumnWidths
                    If Convert.ToBoolean(s.Trim().Length) Then
                        If Not Int32.TryParse(s, intValue) Then
                            invalidIndex = idx
                            invalidValue = s
                        Else
                            idx = idx + 1
                        End If
                    Else
                        idx = idx + 1
                    End If
                Next
                If invalidIndex > -1 Then
                    Dim errMsg As String = "Invalid column width '" + invalidValue + "' located at column " + invalidIndex.ToString()
                    Throw New ArgumentOutOfRangeException(errMsg)
                Else
                    _ColumnWidthString = value
                    If Not DesignMode Then
                        _ColumnWidths.Clear()
                        For Each s As String In columnWdiths
                            If Convert.ToBoolean(s.Trim().Length) Then
                                _ColumnWidths.Add(Convert.ToInt32(s))
                            Else
                                _ColumnWidths.Add(_ColumnWidthDefault)
                            End If
                        Next
                        If DataManager IsNot Nothing Then initializeColumns()
                    End If

                End If
            End If
        End Set
    End Property

    Public Overloads Property DrawMode As DrawMode
        Get
            Return MyBase.DrawMode
        End Get
        Set(ByVal value As DrawMode)
            If value <> DrawMode.OwnerDrawVariable Then
                Throw New NotSupportedException("Needs to be DrawMode.OwnerDrawVariable")
            End If
            MyBase .DrawMode =value 
        End Set
    End Property
    Public Overloads Property DropDownStyle As ComboBoxStyle
        Get
            Return MyBase.DropDownStyle
        End Get
        Set(ByVal value As ComboBoxStyle)
            If value <> ComboBoxStyle.DropDown Then
                Throw New NotSupportedException("ComboBoxStyle.DropDown is the only supported style")
            End If
            MyBase.DropDownStyle = value
        End Set
    End Property
    Public Property LinkedColumnIndex As Integer
        Get
            Return _LinkedColumnIndex
        End Get
        Set(ByVal value As Integer)
            If value < 0 Then
                Throw New ArgumentOutOfRangeException("A column index can not be negative")
            End If
            _LinkedColumnIndex = value
        End Set
    End Property
    Public Overloads Property LinkedTextBox As TextBox
        Get
            Return _LinkedTextBox
        End Get
        Set(ByVal value As TextBox)
            _LinkedTextBox = value
            If _LinkedTextBox IsNot Nothing Then
                _LinkedTextBox.ReadOnly = True
                _LinkedTextBox.TabStop = False
            End If
        End Set
    End Property

    Public ReadOnly Property TotalWidth As Int32
        Get
            Return _TotalWidth
        End Get
    End Property
    Protected Overrides Sub OnDataSourceChanged(ByVal e As System.EventArgs)
        MyBase.OnDataSourceChanged(e)
        initializecolumns()
    End Sub
    

[eaqpi]

Protected Overrides Sub OnDrawItem(ByVal e As System.Windows.Forms.DrawItemEventArgs)
        MyBase.OnDrawItem(e)
        If DesignMode Then Return
        e.DrawBackground()
        Dim boundsRect As Rectangle = e.Bounds
        Dim lastRight As Int32 = 0
        Dim brushForeColor As Color
        If (e.State & DrawItemState.Selected) = 0 Then
            Dim backColor As Color
            backColor = IIf(Convert.ToBoolean(e.Index Mod 2), _BackColorOdd, _BackColorEven)
            Using brushBackColor As SolidBrush = New SolidBrush(backColor)
                e.Graphics.FillRectangle(brushBackColor, e.Bounds)
            End Using
            brushForeColor = Color.Black
        Else
            brushForeColor = Color.White
        End If
        Using linePen As Pen = New Pen(Color.Gray)
            Using Brush As SolidBrush = New SolidBrush(brushForeColor)
                If Not Convert.ToBoolean(_ColumnNames.Count) Then
                    e.Graphics.DrawString(Convert.ToString(Items(e.Index)), Font, Brush, boundsRect)
                Else
                    If RightToLeft.Equals(RightToLeft.Yes) Then
                        Dim rtl As StringFormat = New StringFormat
                        rtl.Alignment = StringAlignment.Near
                        rtl.FormatFlags = StringFormatFlags.DirectionRightToLeft
                        For colIndex As Int32 = _ColumnNames.Count - 1 To 0 Step 1
                            If Convert.ToBoolean(_ColumnWidths(colIndex)) Then
                                Dim item As String = Convert.ToString(FilterItemOnProperty(Items(e.Index), _ColumnNames(colIndex)))
                                boundsRect.X = lastRight
                                boundsRect.Width = _ColumnWidths(colIndex)
                                lastRight = boundsRect.Right
                                e.Graphics.DrawString(item, Font, Brush, boundsRect, rtl)
                                If colIndex > 0 Then
                                    e.Graphics.DrawLine(linePen, boundsRect.Right, boundsRect.Top, boundsRect.Right, boundsRect.Bottom)
                                End If
                            End If
                        Next
                    Else
                        For colindex As Int32 = 0 To _ColumnWidths.Count - 1 Step 1
                            If Convert.ToBoolean(_ColumnWidths(colindex)) Then
                                Dim item As String = Convert.ToString(FilterItemOnProperty(Items(e.Index), _ColumnNames(colindex)))
                                boundsRect.X = lastRight
                                boundsRect.Width = _ColumnWidths(colindex)
                                lastRight = boundsRect.Right
                                e.Graphics.DrawString(item, Font, Brush, boundsRect)
                                If colindex < _ColumnNames.Count - 1 Then
                                    e.Graphics.DrawLine(linePen, boundsRect.Right, boundsRect.Top, boundsRect.Right, boundsRect.Bottom)
                                End If
                            End If
                        Next
                    End If
                End If
            End Using
        End Using
        e.DrawFocusRectangle()
    End Sub

    Protected Overrides Sub OnDropDown(ByVal e As System.EventArgs)
        MyBase.OnDropDown(e)
        If _TotalWidth > 0 Then
            If (Items.Count > MaxDropDownItems) Then
                Me.DropDownWidth = _TotalWidth + SystemInformation.VerticalScrollBarWidth
            Else
                Me.DropDownWidth = _TotalWidth
            End If
        End If
    End Sub
    Protected Overrides Sub OnKeyDown(ByVal e As System.Windows.Forms.KeyEventArgs)
        MyBase.OnKeyDown(e)
        If e.KeyCode = Keys.Delete OrElse e.KeyCode = Keys.Escape Then
            SelectedIndex = -1
            Text = ""
            If _LinkedTextBox IsNot Nothing Then
                _LinkedTextBox.Text = ""
            End If
            'ElseIf e.KeyCode = Keys.F3 Then
            '   If OpenSearchForm IsNot Nothing Then
            'OpenSearchForm(Me, System.EventArgs.Empty)
            'End If
        End If
    End Sub
    Protected Overrides Sub OnKeyPress(ByVal e As System.Windows.Forms.KeyPressEventArgs)
        MyBase.OnKeyPress(e)
        Dim idx As Int32 = -1
        Dim toFind As String
        DroppedDown = _AutoDropdown
        If (Not Char.IsControl(e.KeyChar)) Then
            If _AutoComplete Then
                toFind = Text.Substring(0, SelectionStart) + e.KeyChar
                idx = FindStringExact(toFind)
                If idx = -1 Then
                    idx = FindString(toFind)
                Else
                    DroppedDown = False
                End If
                If idx <> -1 Then
                    SelectedIndex = idx
                    SelectionStart = toFind.Length
                    SelectionLength = Text.Length - SelectionStart
                Else
                    e.KeyChar = ChrW(0)
                End If
            Else
                idx = FindString(e.KeyChar.ToString, SelectedIndex)
                If idx <> -1 Then
                    SelectedIndex = idx
                End If
            End If
            If e.KeyChar = ChrW(Keys.Back) AndAlso _AutoComplete AndAlso Convert.ToBoolean(SelectionStart) Then
                toFind = Text.Substring(0, SelectionStart - 1)
                idx = FindString(toFind)
                If idx <> -1 Then
                    SelectedIndex = idx
                    SelectionStart = toFind.Length
                    SelectionLength = Text.Length - SelectionStart
                End If
            End If
        End If
        e.Handled = True
    End Sub
    Protected Overrides Sub OnSelectedValueChanged(ByVal e As System.EventArgs)
        MyBase.OnSelectedValueChanged(e)
        If _LinkedTextBox IsNot Nothing Then
            If _LinkedColumnIndex < _ColumnNames.Count Then
                _LinkedTextBox.Text = Convert.ToString(FilterItemOnProperty(SelectedItem, _ColumnNames(_LinkedColumnIndex)))
            End If
        End If
    End Sub
    Protected Overrides Sub OnValueMemberChanged(ByVal e As System.EventArgs)
        MyBase.OnValueMemberChanged(e)
        initializevaluemembercolumn()
    End Sub
    Private Sub InitializeColumns()
        If Not Convert.ToBoolean(_ColumnNameString.Length) Then
            Dim propertyDescriptorCollection As System.ComponentModel.PropertyDescriptorCollection = DataManager.GetItemProperties
            _TotalWidth = 0
            _ColumnNames.Clear()
            For colindex As Int32 = 0 To propertyDescriptorCollection.Count - 1 Step 1
                _ColumnNames.Add(propertyDescriptorCollection(colindex).Name)
                If (colindex >= _ColumnWidths.Count) Then
                    _ColumnWidths.Add(_ColumnWidthDefault)
                End If
                _TotalWidth += _ColumnWidths(colindex)
            Next
        Else
            _TotalWidth = 0
            For colIndex As Int32 = 0 To _ColumnNames.Count Step 1
                If colIndex >= _ColumnWidths.Count Then
                    _ColumnWidths.Add(_ColumnWidthDefault)
                End If
                _TotalWidth += _ColumnWidths(colIndex)
            Next
        End If
        If (_LinkedColumnIndex >= _ColumnNames.Count) Then
            _LinkedColumnIndex = 0
        End If
    End Sub

    Private Sub InitializeValueMemberColumn()
        Dim colIndex As Int32 = 0
        For Each columnName As String In _ColumnNames
            If String.Compare(columnName, ValueMember, True, CultureInfo.CurrentUICulture) = 0 Then
                _ValueMemberColumnIndex = colIndex
                Exit For
            End If
            colIndex += 1
        Next
    End Sub
End Class

[eaqpi]

窗体代码

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim p As MultiColumnComboBox
        p = New MultiColumnComboBox
        Me.SuspendLayout()
        '
        'ComboBox1
        '
        p.FormattingEnabled = True
        p.Location = New System.Drawing.Point(32, 40)
        p.Name = "ComboBox1"
        p.Size = New System.Drawing.Size(121, 20)
        p.TabIndex = 0
        '
        'Form1
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 12.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(292, 273)
        Me.Controls.Add(p)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)
        Dim dt As New DataTable("Employees")
        dt.Columns.Add("Employee ID", GetType(String))
        dt.Columns.Add("Name", GetType(String))
        dt.Columns.Add("Designation", GetType(String))
        dt.Rows.Add(New String() {"D1", "Natalia", "Developer"})
        dt.Rows.Add(New String() {"D2", "Jonathan", "Developer"})
        dt.Rows.Add(New String() {"D3", "Jake", "Developer"})
        dt.Rows.Add(New String() {"D4", "Abraham", "Developer"})
        dt.Rows.Add(New String() {"T1", "Mary", "Team Lead"})
        dt.Rows.Add(New String() {"PM1", "Calvin", "Project Manager"})
        dt.Rows.Add(New String() {"T2", "Sarah", "Team Lead"})
        dt.Rows.Add(New String() {"D12", "Monica", "Developer"})
        dt.Rows.Add(New String() {"D13", "Donna", "Developer"})

        p.DataSource = dt
        p.DisplayMember = "Employee ID"
        p.ValueMember = "Name"
    End Sub
End Class

[wind_cloud2011]

好长的代码，

[wind_cloud2011]

这么长，看晕的，想实现什么功能？

[wind_cloud2011]

就是建立一个ComboBox控件，将表的数据Employee ID绑定在控件上

[eaqpi]

就是实现一个表格状的combobox