Winform ComboBox独立绘制下拉选项的字体颜色

众所周知，cbo1.ForeColor会同时改变cbo1.Text和下拉选项字体颜色。

独立绘制下拉选项字体颜色，ForeColor 只对 cbo1.Text 颜色有效的办法，示例：

private void cb7_DrawItem(object sender, DrawItemEventArgs e){    DrawCboItems(sender, e);}private void cb7_SelectedIndexChanged(object sender, EventArgs e){    SetCboTextColor(sender);}private void SetCboTextColor(object sender){    ComboBox cbx = sender as ComboBox;    if (cbx.Text == "+")        cbx.ForeColor = Color.Red;    else        cbx.ForeColor = Color.Black;}private void DrawCboItems(object sender, DrawItemEventArgs e){    ComboBox cbo = sender as ComboBox;    //初始化字体和背景色    Pen fColor = new Pen(Color.Black);    Pen bColor = new Pen(Color.White);    switch (e.Index)    {　　　　 //下拉选项的索引    　　case 1:    　　{        　　fColor = new Pen(Color.Red);        　　break;    　　}    }    e.Graphics.FillRectangle(bColor.Brush, e.Bounds);    e.Graphics.DrawString((string)cbo.Items[e.Index], this.Font, fColor.Brush, e.Bounds);}