C# 实现颜色下拉列表框

代码如下：

class ColorDropDownList : ComboBox { public ColorDropDownList() : base() { this.DropDownStyle = ComboBoxStyle.DropDownList; this.DrawMode = DrawMode.OwnerDrawFixed; fillList(); this.SelectedIndex = 0; this.DrawItem += new DrawItemEventHandler(ColorDropDownList_DrawItem); } private void fillList() { string[] names = Enum.GetNames(typeof(KnownColor)); this.Items.AddRange(names); } private void ColorDropDownList_DrawItem(object sender, DrawItemEventArgs e) { string colorName = (string)this.Items[e.Index]; Color color = Color.FromName(colorName); Rectangle rect = new Rectangle(e.Bounds.X, e.Bounds.Y, e.Bounds.Width / 4, e.Bounds.Height - 2); Brush brush = new SolidBrush(color); e.Graphics.DrawRectangle(new Pen(Color.Black), rect); rect.X += 1; rect.Y += 1; rect.Width -= 1; rect.Height -= 1; e.Graphics.FillRectangle(brush, rect); rect.Offset(rect.Width + 4, 0); e.Graphics.DrawString(colorName, e.Font, Brushes.Black, rect.Location); } }

效果图如下：