C#自定义签名章实现方法

本文实例讲述了C#自定义签名章实现方法。分享给大家供大家参考。具体实现方法如下：

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;
 }
}
}

希望本文所述对大家的C#程序设计有所帮助。