摘要：
http://blog.itpub.net/29251214/viewspace-774395/http://blog.csdn.net/czp_huster/article/details/50184691http://www.cnblogs.com/Lixinhua-GoOn/p/4046042.htmldevtreest控件，它显示三角字符或+字符。解决方案1：在程序中。c
http://blog.itpub.net/29251214/viewspace-774395/
http://blog.csdn.net/czp_huster/article/details/50184691
http://www.cnblogs.com/Lixinhua-GoOn/p/4046042.html
dev treelist控件，显示3角符，或显示+ -符的控制
解决方案1：
在 program.cs中把 下面一句暂时注解，你就会发现所有的 treelist会自动显示 + -号;
如果放出来，就显示3角符
DevExpress.LookAndFeel.UserLookAndFeel.Default.SetSkinStyle("DevExpress Style");
解决方案2：
自己画+-号
private void treeList1_CustomDrawNodeButton(object sender, DevExpress.XtraTreeList.CustomDrawNodeButtonEventArgs e)
{
Brush backBrush = new System.Drawing.Drawing2D.LinearGradientBrush(e.Bounds, Color.White, Color.Black,
em.Drawing.Drawing2D.LinearGradientMode.ForwardDiagonal);
e.Graphics.FillRectangle(backBrush, e.Bounds);
// painting 3D borders
ControlPaint.DrawBorder3D(e.Graphics, e.Bounds, Border3DStyle.Flat);
// determining the character to display
string displayCharacter = e.Expanded ? "-" : "+";
// formatting the output character
StringFormat outCharacterFormat = new StringFormat();
outCharacterFormat.Alignment = StringAlignment.Center;
outCharacterFormat.LineAlignment = StringAlignment.Center;
// painting the character
e.Graphics.DrawString(displayCharacter, new Font("Verdana", 8),
new SolidBrush(Color.White), e.Bounds, outCharacterFormat);
// prohibiting default painting
e.Handled = true;
}