为自定义控件添加PropertyGrid项

protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
{
    Pen pen = new Pen(drawLineColor);
    pen.Width = 2;
    // 绘制一条水平分割线  
    e.Graphics.DrawLine(pen, new Point(5, 5), new Point(this.Width - 5, 5));
    ////绘制panel的背景图像  
    //if (BackgroundImage != null) e.Graphics.DrawImage(this.BackgroundImage, new Point(0, 0));  
}
// 存储颜色值的内部变量    
private Color drawLineColor = Color.Red;
[Description("修改此值，可修改分割线的颜色"), Category("自定义属性")]
// 控件的自定义属性值 
public Color DrawLineColor
{
    get
    {
        return drawLineColor;
    }
    set
    {
        drawLineColor = value;
        // 此处修改，为自定义属性变动时，执行的操作  
        // 此处当颜色值属性变动时，使用新的颜色，使自定义控件重绘 
        this.Invalidate();
    }
}

来源：https://www.cnblogs.com/jizhiqiliao/p/11584002.html