用处及效果

准备工作

没什么可准备的，直接往下看吧

开始

添加一个类UCPanelQuote继承 Panel

添加2个属性

/// <summary>
        /// The border color
        /// </summary>
        private Color borderColor = LineColors.Light;

        /// <summary>
        /// Gets or sets the color of the border.
        /// </summary>
        /// <value>The color of the border.</value>
        [Description("边框颜色"), Category("自定义")]
        public Color BorderColor
        {
            get { return borderColor; }
            set
            {
                borderColor = value;
                this.Invalidate();
            }
        }

        /// <summary>
        /// The left color
        /// </summary>
        private Color leftColor = StatusColors.Danger;

        /// <summary>
        /// Gets or sets the color of the left.
        /// </summary>
        /// <value>The color of the left.</value>
        [Description("左侧颜色"), Category("自定义")]
        public Color LeftColor
        {
            get { return leftColor; }
            set
            {
                leftColor = value;
                this.Invalidate();
            }
        }

为了画边框和左边的颜色，设置一下Padding

public UCPanelQuote() : base()
{
    Padding = new Padding(5, 1, 1, 1);
}

重绘

protected override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);
            e.Graphics.SetGDIHigh();

            e.Graphics.DrawLines(new Pen(borderColor), new Point[] 
            { 
                new Point(e.ClipRectangle.Left,e.ClipRectangle.Top),
                new Point(e.ClipRectangle.Right-1,e.ClipRectangle.Top),
                new Point(e.ClipRectangle.Right-1,e.ClipRectangle.Bottom-1),
                new Point(e.ClipRectangle.Left,e.ClipRectangle.Bottom-1),
                new Point(e.ClipRectangle.Left,e.ClipRectangle.Top)
            });

            e.Graphics.FillRectangle(new SolidBrush(leftColor), new Rectangle(0, 0, 5, this.Height));
        }