查看完整版本: 颜色下拉COMBOBOX控件(vb.net)

颜色下拉COMBOBOX控件(vb.net)

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（2005/08/06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