颜色下拉COMBOBOX控件(vb.net)

   前不久，有位朋友发帖，寻求颜色选择的COMBOBOX  的制作方法，经过试验，整理了出来，仅供参考。

（注：如有引用，请注明出处和作者）

                                                                   --闵峰（东莞）

 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

查看本文来源