VB.net中COMBOBOX控件下拉颜色的变化

 Private Sub filllistboxwithcolors()
        Me.ComboBox1.DrawMode = DrawMode.OwnerDrawFixed
        Me.ComboBox1.DropDownStyle = ComboBoxStyle.DropDownList
        Me.ComboBox1.ItemHeight = 15
        '避免闪烁beginupdate
        Me.ComboBox1.BeginUpdate()
        ComboBox1.Items.Clear()
        Dim pi As Reflection.PropertyInfo
        For Each pi In GetType(Color).GetProperties(Reflection.BindingFlags.Public Or Reflection.BindingFlags.Static)
            Me.ComboBox1.Items.Add(pi.Name)
        Next
        ComboBox1.EndUpdate()

    End Sub

 Private Sub ComboBox1_DrawItem(ByVal sender As Object,ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles ComboBox1.DrawItem
        If e.Index < 0 Then Exit Sub
       
        Dim rect As Rectangle = e.Bounds '每一项的边框
       
        '绘制项如果被选中则显示高亮显示背景,否则用白色
        If e.State And DrawItemState.Selected Then
            e.Graphics.FillRectangle(SystemBrushes.Highlight,rect)
        Else
            e.Graphics.FillRectangle(SystemBrushes.Window,rect)
        End If

        Dim colorname As String = ComboBox1.Items(e.Index)
        Dim b As New SolidBrush(Color.FromName(colorname))

        '缩小选定项区域()
        rect.Inflate(-16,-2)
        '填充颜色(文字对应的颜色)
        e.Graphics.FillRectangle(b,rect)
        '绘制边框()
        e.Graphics.DrawRectangle(Pens.Black,rect)
        Dim b2 As Brush
        '确定显示的文字的颜色()
        If CInt(b.Color.R) + CInt(b.Color.G) + CInt(b.Color.B) > 128 * 3 Then
            b2 = Brushes.Black
        Else
            b2 = Brushes.White

        End If
        e.Graphics.DrawString(colorname,Me.ComboBox1.Font,b2,rect.X,rect.Y)

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object,ByVal e As System.EventArgs) Handles MyBase.Load
        filllistboxwithcolors()
    End Sub

（编辑：李大同）

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