一个自定义的Combox

如何在windows标准的combox中加入自定义的item

 

Public Class ComboPatternClass ComboPattern
    Inherits System.Windows.Forms.ComboBox

Component Designer generated code#Region " Component Designer generated code "

    Public Sub New()Sub New(ByVal Container As System.ComponentModel.IContainer)
        MyClass.New()

        'Required for Windows.Forms Class Composition Designer support
        Container.Add(Me)
    End Sub

    Public Sub New()Sub New()
        MyBase.New()

        'This call is required by the Component Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Component overrides dispose to clean up the component list.
    Protected Overloads Overrides Sub Dispose()Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Required by the Component Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Component Designer
    'It can be modified using the Component Designer.
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()Sub InitializeComponent()
        components = New System.ComponentModel.Container
    End Sub

#End Region

    'get or set current pattern style
    Private _patternstyle As System.Drawing.Drawing2D.HatchStyle
    Public Property PatternStyle()Property PatternStyle() As System.Drawing.Drawing2D.HatchStyle
        Get
            Return _patternstyle
        End Get
        Set(ByVal Value As System.Drawing.Drawing2D.HatchStyle)
            _patternstyle = Value
        End Set
    End Property


    Protected Overrides Sub OnDrawItem()Sub OnDrawItem(ByVal e As System.Windows.Forms.DrawItemEventArgs)
        MyBase.OnDrawItem(e)
        Me.DrawMode = DrawMode.OwnerDrawFixed

        If (e.State And DrawItemState.Selected) = DrawItemState.Selected Then
            Dim selectBrush As New SolidBrush(Me.BackColor)
            e.Graphics.FillRectangle(selectBrush, e.Bounds)
            Dim selectPen As New Pen(Color.Gray)
            selectPen.DashStyle = Drawing2D.DashStyle.Dash
            e.Graphics.DrawRectangle(selectPen, e.Bounds)
        Else
            Dim selectBrush As New SolidBrush(Me.BackColor)
            e.Graphics.FillRectangle(selectBrush, e.Bounds)
            Dim selectPen As New Pen(Me.BackColor)
            e.Graphics.DrawRectangle(selectPen, e.Bounds)
        End If
        ' e.DrawBackground()
        e.DrawFocusRectangle()

        Dim myBrush As System.Drawing.Drawing2D.HatchBrush

        Select Case e.Index
            Case 0
                'no pattern
            Case 1
                'BackwardDiagonal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.BackwardDiagonal, Color.Black, Me.BackColor)
            Case 2
                'Cross
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.Cross, Color.Black, Me.BackColor)

            Case 3
                'DarkDownwardDiagonal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DarkDownwardDiagonal, Color.Black, Me.BackColor)

            Case 4
                'DarkHorizontal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DarkHorizontal, Color.Black, Me.BackColor)

            Case 5
                'DarkUpwardDiagonal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DarkUpwardDiagonal, Color.Black, Me.BackColor)
            Case 6
                'DarkVertical
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DarkVertical, Color.Black, Me.BackColor)
            Case 7
                'DashedDownwardDiagonal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DashedDownwardDiagonal, Color.Black, Me.BackColor)

            Case 8
                'DashedHorizontal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DashedHorizontal, Color.Black, Me.BackColor)

            Case 9
                'DashedUpwardDiagonal
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DashedUpwardDiagonal, Color.Black, Me.BackColor)
            Case 10
                'DashedVertical
                myBrush = New System.Drawing.Drawing2D.HatchBrush(Drawing2D.HatchStyle.DashedVertical, Color.Black, Me.BackColor)

        End Select

        'e.Graphics.DrawRectangle(myPen, New Rectangle(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height))
        If e.Index = 0 Then
            Dim myBrush1 As New SolidBrush(Color.Black)
            e.Graphics.DrawString(Me.Items(e.Index), e.Font, myBrush1, New RectangleF(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height))
        Else
            'e.Graphics.DrawLine(myPen, e.Bounds.X, e.Bounds.Y + CInt(e.Bounds.Height / 2), e.Bounds.X + e.Bounds.Width, e.Bounds.Y + CInt(e.Bounds.Height / 2))
            e.Graphics.FillRectangle(myBrush, e.Bounds)

        End If


    End Sub


    Private Sub ComboPattern_SelectedIndexChanged()Sub ComboPattern_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.SelectedIndexChanged
        If (Me.DropDownStyle <> ComboBoxStyle.DropDownList) Then
            Me.DropDownStyle = ComboBoxStyle.DropDownList
        End If

        Dim currentPattern As System.Drawing.Drawing2D.HatchStyle

        Select Case Me.SelectedIndex
            Case 0
                'no pattern, use ZigZag to instead of
                currentPattern = Drawing2D.HatchStyle.ZigZag

            Case 1
                'BackwardDiagonal
                currentPattern = Drawing2D.HatchStyle.BackwardDiagonal
            Case 2
                'Cross
                currentPattern = Drawing2D.HatchStyle.Cross

            Case 3
                'DarkDownwardDiagonal
                currentPattern = Drawing2D.HatchStyle.DarkDownwardDiagonal

            Case 4
                'DarkHorizontal
                currentPattern = Drawing2D.HatchStyle.DarkHorizontal

            Case 5
                'DarkUpwardDiagonal
                currentPattern = Drawing2D.HatchStyle.DarkUpwardDiagonal

            Case 6
                'DarkVertical
                currentPattern = Drawing2D.HatchStyle.DarkVertical

            Case 7
                'DashedDownwardDiagonal
                currentPattern = Drawing2D.HatchStyle.DashedDownwardDiagonal


            Case 8
                'DashedHorizontal
                currentPattern = Drawing2D.HatchStyle.DarkHorizontal

            Case 9
                'DashedUpwardDiagonal
                currentPattern = Drawing2D.HatchStyle.DashedUpwardDiagonal

            Case 10
                'DashedVertical
                currentPattern = Drawing2D.HatchStyle.DashedVertical
        End Select
        Me.PatternStyle = currentPattern
    End Sub




End Class

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