2.C#Panel扩展控件

1.解决方案下添加新建项目新建类库

2. 在项目下添加新建项选择新建组件类

3.先引用，然后导入两个命名空间

4.因为是扩展控件，把继承自Component改成继承自Panel

 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;

 using System.Linq;
 using System.Security.Principal;
 using System.Text;
 using System.Windows.Forms;
 using System.Drawing.Drawing2D;
 using System.Drawing.Text;
 using System.Drawing;
 namespace FJZControl
 {
     public partial class FJZPanel : Panel
     {
         public FJZPanel()
         {
             InitializeComponent();
         }

         public FJZPanel(IContainer container)
         {
             container.Add(this);

             InitializeComponent();
         }
         #region 属性
         private Color headBackColor = Color.LimeGreen;
         [Category("我的自定义Panel控件属性")]
         [Description("标题的背景颜色")]
         public Color HeadBackColor
         {
             get
             {
                 return headBackColor;
             }

             set
             {
                 headBackColor = value;

                 this.Invalidate();
             }
         }

         private Color headForeColor = Color.Black;
         [Category("我的自定义Panel控件属性")]
         [Description("标题的背景颜色")]
         public Color HeadForeColor
         {
             get
             {
                 return headForeColor;
             }

             set
             {
                 headForeColor = value;

                 this.Invalidate();
             }
         }

         private int headHeight = ;
         [Category("我的自定义Panel控件属性")]
         [Description("标题的高度")]
         public int HeadHeight
         {
             get
             {
                 return headHeight;
             }

             set
             {
                 headHeight = value;
                 this.Invalidate();
             }
         }

         private string headText = "标题名称";
         [Category("我的自定义Panel控件属性")]
         [Description("标题的名称")]
         public string HeadText
         {
             get { return headText; }
             set
             {
                 this.headText = value;
                 this.Invalidate();
             }

         }

         private float linearScale=0.4f;
         [Category("我的自定义Panel控件属性")]
         [Description("渐变程度")]
         public float LinearScale
         {
             get
             {
                 return linearScale;
             }

             set
             {
                 linearScale = value;
                 this.Invalidate();
             }
         }
         #endregion

         #region 字段
         Graphics g;
         Pen p;
         SolidBrush sb;
         #endregion
         #region 方法
         protected override void OnPaint(PaintEventArgs e)
         {
             base.OnPaint(e);
             //自定义绘制过程

             //获取这个画布
              g = e.Graphics;

             //设置画布
             SetGrahics();

             //第一步:画标题框
             using (LinearGradientBrush brush = new LinearGradientBrush(new PointF(, ), new PointF(, this.headHeight), GetStartLinearColor(this.headBackColor), this.headBackColor))
             {
                 g.FillRectangle(brush, new RectangleF(, , this.Width, this.headHeight));
             }
             //第二步:标题
             StringFormat sf = new StringFormat();
             sf.Alignment = StringAlignment.Center;
             sf.LineAlignment = StringAlignment.Center;
             using(SolidBrush sb=new SolidBrush(this.headForeColor))
             {
                 g.DrawString(this.headText, this.Font, sb,new RectangleF( ,,this.Width, this.headHeight), sf);
             }
             //第三步:画边框
             using(Pen p=new Pen(this.headBackColor))
             {
                 g.DrawRectangle(p, , , this.Width-, this.Height-);
                 g.DrawLine(p, , this.HeadHeight, this.Width - , this.headHeight - );
             }
         }
         //设置画布属性
         private void SetGrahics()
         {
             g.SmoothingMode = SmoothingMode.AntiAlias;
             g.SmoothingMode = SmoothingMode.HighQuality;

             g.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;
             g.TextRenderingHint = TextRenderingHint.AntiAlias;

         }

         //获取
         private Color GetStartLinearColor(Color EndLinearColor)
         {
             return Color.FromArgb((int)(EndLinearColor.R + ( - EndLinearColor.R) * this.linearScale), (int)(EndLinearColor.G + ( - EndLinearColor.G) * this.linearScale), (int)(EndLinearColor.B + ( - EndLinearColor.B) * this.linearScale));
         }
         #endregion
     }
 }

效果如下：