C#自定义签名章实现方法

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Drawing;using System.Drawing.Imaging;using System.Drawing.Drawing2D;namespace WfpApp{ public class DrawCachet {  /// <summary>  /// 自定义椭圆形签名章  /// </summary>  /// <param name="Width">宽度，画出的签名章只有这宽度的一半</param>  /// <param name="Height">高度，画出的签名章只有这高度的一半</param>  /// <param name="test">签名章上名字</param>  /// <param name="IsRotate">签名章是否旋转角度</param>  /// <param name="angle">旋转角度的大小</param>  /// <returns></returns>  public static Bitmap GetDrawCircleCachet(int Width, int Height, string test, bool IsRotate, int angle)  {   //记录圆画笔的粗细    int Circle_Brush = 2;   //画布   Bitmap bitmap = new Bitmap(Width, Height);   //定义字符串的样式    Font var_Font = new Font("Arial", 13, FontStyle.Bold);   //定义一个矩形 ,设置圆的绘制区    Rectangle rect = new Rectangle(10, 10, Width / 2, Height / 2);   //实例化Graphic类    Graphics g = System.Drawing.Graphics.FromImage(bitmap);   //消除绘制图形的锯齿，平滑   g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;   //以白色清空panelCachet画布背景    g.Clear(Color.White);   //设置画笔的颜色   Pen mypen = new Pen(Color.Red, Circle_Brush);   //绘制圆    g.DrawEllipse(mypen, rect);   //设置文字的字体样式    Font star_Font = new Font("Arial", 12, FontStyle.Regular);   //对字符串进行宽度和长度测量    SizeF var_Size = g.MeasureString(test, star_Font);   float CircleZjW = rect.Width + 2 * Circle_Brush;   float CircleZJH = rect.Height + 2 * Circle_Brush;   float x = (CircleZjW - var_Size.Width) / 2F + rect.X;   float y = (CircleZJH - var_Size.Height) / 2F + rect.Y;   //在指定的位置绘制文字   g.DrawString(test, star_Font, mypen.Brush, new PointF(x, y));   if (IsRotate)    bitmap = Rotate(bitmap, angle);   return bitmap;  }  /// <summary>  /// 自定义矩形签名章  /// </summary>  /// <param name="width">宽度，画出的签名章只有这宽度的一半</param>  /// <param name="height">高度，画出的签名章只有这高度的一半</param>  /// <param name="name">签名章上名字</param>  /// <param name="IsRotate">签名章是否旋转角度</param>  /// <param name="angle">旋转角度的大小</param>  /// <returns></returns>  public static Bitmap GetDrawRectangle(int width, int height, string name, bool IsRotate, int angle)  {   //记录圆画笔的粗细    int Circle_Brush = 2;   //画布   Bitmap bitmap = new Bitmap(width, height);   //定义字符串的样式    Font var_Font = new Font("Arial", 13, FontStyle.Bold);   //定义一个矩形 ,设置圆的绘制区    Rectangle rect = new Rectangle(10, 10, width / 2, height / 2);   //实例化Graphic类    Graphics g = System.Drawing.Graphics.FromImage(bitmap);   //消除绘制图形的锯齿，平滑   g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;   //以白色清空panelCachet画布背景    g.Clear(Color.White);   //设置画笔的颜色   Pen mypen = new Pen(Color.Red, Circle_Brush);   //绘制圆    g.DrawRectangle(mypen, rect);   //设置文字的字体样式    Font star_Font = new Font("Arial", 12, FontStyle.Regular);   //对字符串进行宽度和长度测量    SizeF var_Size = g.MeasureString(name, star_Font);   float CircleZjW = rect.Width + 2 * Circle_Brush;   float CircleZJH = rect.Height + 2 * Circle_Brush;   float x = (CircleZjW - var_Size.Width) / 2F + rect.X;   float y = (CircleZJH - var_Size.Height) / 2F + rect.Y;   //在指定的位置绘制文字   g.DrawString(name, star_Font, mypen.Brush, new PointF(x, y));   if (IsRotate)    bitmap = Rotate(bitmap, angle);   return bitmap;  }  /// <summary>  /// 签名章旋转  /// </summary>  /// <param name="b">Bitmap图章</param>  /// <param name="angle">旋转度</param>  /// <returns></returns>  static Bitmap Rotate(Bitmap b, int angle)  {   angle = angle % 360;   //弧度转换   double radian = angle * Math.PI / 180.0;   double cos = Math.Cos(radian);   double sin = Math.Sin(radian);   //原图的宽和高   int w = b.Width;   int h = b.Height;   int W = (int)(Math.Max(Math.Abs(w * cos - h * sin), Math.Abs(w * cos + h * sin)));   int H = (int)(Math.Max(Math.Abs(w * sin - h * cos), Math.Abs(w * sin + h * cos)));   //目标位图   Bitmap dsImage = new Bitmap(W, H);   System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(dsImage);   g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;   g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;   //计算偏移量   Point Offset = new Point((W - w) / 2, (H - h) / 2);   //构造图像显示区域：让图像的中心与窗口的中心点一致   Rectangle rect = new Rectangle(Offset.X, Offset.Y, w, h);   Point center = new Point(rect.X + rect.Width / 2, rect.Y + rect.Height / 2);   g.TranslateTransform(center.X, center.Y);   g.RotateTransform(360 - angle);   //恢复图像在水平和垂直方向的平移   g.TranslateTransform(-center.X, -center.Y);   g.DrawImage(b, rect);   //重至绘图的所有变换   g.ResetTransform();   g.Save();   g.Dispose();   //dsImage.Save("yuancd.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);   return dsImage;  } }}