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。