C# 生成印章

1、界面实现及按钮事件

 

///点击按钮事件
 private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                string imageUrl = "C:\\Users\\Administrator\\Desktop\\新建文件夹 (2)";
                string imageFormat = "jpg";
                string outerCircleText = "测试公司";
                string interiorText = "测试部门";
                this.txt_WordsExtract.Text = Resource.Contract.CreatPublicSeal.CreatSeal(outerCircleText, interiorText, imageUrl, imageFormat);
            }
            catch (Exception ex)
            {
                throw;
            }
        }

 

2、生成印章源码

    /// <summary>
    /// 生成电子印章
    /// </summary>
    public class CreatPublicSeal
    {
        //定义字符串的字体样式
        Font Var_Font = new Font("Arial", 12, FontStyle.Bold);
        //记录圆的直径
        private static int tem_Line = 160;
        //设置圆画笔的粗细
        private static int circularity_W = 4;
        //圆线条，设置圆的绘制区域
        private static Rectangle rect = new Rectangle(circularity_W, circularity_W, tem_Line - circularity_W * 2, tem_Line - circularity_W * 2);
        //字体间距
        private static int _letterspace = 4;
        private static Char_Direction _chardirect = Char_Direction.Center;
        private static int _degree = 90;
        //字体圆弧所在圆，比外面圆圈小
        private static int space = 16;
        private static Rectangle NewRect = new Rectangle(new Point(rect.X + space, rect.Y + space), new Size(rect.Width - 2 * space, rect.Height - 2 * space));

        /// <summary>
        /// 创建公司公共印章得到图片存储地址
        /// </summary>
        /// <param name="outerCircleText">最外圈文字</param>
        /// <param name="interiorText">内圈文字</param>
        /// <param name="imageUrl">保存路径</param>
        /// <param name="imageFormat">生成格式</param>
        /// <returns></returns>
        public static string CreatSeal(string outerCircleText, string interiorText, string imageUrl, string imageFormat)
        {
            #region 初始化和设置
            //画图初始化
            Bitmap bMap = new Bitmap(160, 160);
            Graphics g = Graphics.FromImage(bMap);
            //消除绘制图形的锯齿
            g.SmoothingMode = SmoothingMode.AntiAlias;
            //以白色清空panel1控件的背景
            g.Clear(Color.White);
            //设置画笔的颜色
            Pen myPen = new Pen(Color.Red, circularity_W);
            //绘制圆
            g.DrawEllipse(myPen, rect);
            #endregion

            #region 绘制星号
            string star_Str = "★";
            //设置星号的字体样式
            Font star_Font = new Font("Arial", 30, FontStyle.Regular);
            //对指定字符串进行测量
            SizeF star_Size = g.MeasureString(star_Str, star_Font);
            //要指定的位置绘制星号
            PointF star_xy = new PointF(tem_Line / 2 - star_Size.Width / 2, tem_Line / 2 - star_Size.Height / 2);
            g.DrawString(star_Str, star_Font, myPen.Brush, star_xy);
            #endregion

            #region 绘制中间文字
            //绘制中间文字
            int var_len = interiorText.Length;
            //定义中间字体样式
            Font Var_Font = new Font("Arial", 22 - var_len * 2, FontStyle.Bold);
            //对中间字符串进行测量
            SizeF Var_Size = g.MeasureString(interiorText, Var_Font);
            //要指定的位置绘制中间文字
            PointF Var_xy = new PointF(tem_Line / 2 - Var_Size.Width / 2, tem_Line / 2 + star_Size.Height / 2 - Var_Size.Height / 2 + 5);
            g.DrawString(interiorText, Var_Font, myPen.Brush, Var_xy);
            #endregion
            
            #region 绘制外圈文字
            //最外圈文字
            if (!string.IsNullOrWhiteSpace(outerCircleText))
            {
                outerCircleText = outerCircleText + "专用章";
            }
            //获取字符串的长度
            int text_len = outerCircleText.Length;
            //定义最外圈字体样式
            Font text_Font = new Font("Arial", 25 - text_len, FontStyle.Bold);
            Pen myPenbush = new Pen(Color.White, circularity_W);
            float[] fCharWidth = new float[text_len];
            float fTotalWidth = ComputeStringLength(outerCircleText, g, fCharWidth, _letterspace, _chardirect, text_Font);
            double fStartAngle, fSweepAngle;
            fSweepAngle = fTotalWidth * 360 / (NewRect.Width * Math.PI);
            fStartAngle = 270 - fSweepAngle / 2;
            PointF[] pntChars = new PointF[text_len];
            double[] fCharAngle = new double[text_len];
            ComputeCharPos(fCharWidth, pntChars, fCharAngle, fStartAngle);
            for (int i = 0; i < text_len; i++)
            {
                DrawRotatedText(g, outerCircleText[i].ToString(), (float)(fCharAngle[i] + _degree), pntChars[i], text_Font, myPenbush);
            }
            #endregion

            #region 保存
            if (!imageUrl.EndsWith("\\") && !imageUrl.EndsWith("/"))
            {
                imageUrl = imageUrl + "\\";
            }
            if (!imageFormat.StartsWith("."))
            {
                imageFormat = "." + imageFormat;
            }
            string imageName = DateTime.Now.ToString("yyyyMMddHHmmss") + imageFormat;
            string fileName = imageUrl + imageName;
            bMap.Save(fileName);
            #endregion
            return fileName;
        }
        /// <summary>
        /// 计算字符串总长度和每个字符长度
        /// </summary>
        /// <param name="sText"></param>
        /// <param name="g"></param>
        /// <param name="fCharWidth"></param>
        /// <param name="fIntervalWidth"></param>
        /// <returns></returns>
        private static float ComputeStringLength(string sText, Graphics g, float[] fCharWidth, float fIntervalWidth, Char_Direction Direction, Font text_Font)
        {
            // Init字符串格式
            StringFormat sf = new StringFormat();
            sf.Trimming = StringTrimming.None;
            sf.FormatFlags = StringFormatFlags.NoClip | StringFormatFlags.NoWrap | StringFormatFlags.LineLimit;
            // 衡量整个字符串长度
            SizeF size = g.MeasureString(sText, text_Font, (int)text_Font.Style);
            RectangleF rect = new RectangleF(0f, 0f, size.Width, size.Height);
            // 测量每个字符大小
            CharacterRange[] crs = new CharacterRange[sText.Length];
            for (int i = 0; i < sText.Length; i++)
            { crs[i] = new CharacterRange(i, 1); }
            // 复位字符串格式
            sf.FormatFlags = StringFormatFlags.NoClip;
            sf.SetMeasurableCharacterRanges(crs);
            sf.Alignment = StringAlignment.Near;
            // 得到每一个字符大小
            Region[] regs = g.MeasureCharacterRanges(sText, text_Font, rect, sf);
            float fTotalWidth = 0f;
            for (int i = 0; i < regs.Length; i++)
            {
                if (Direction == Char_Direction.Center || Direction == Char_Direction.OutSide)
                { fCharWidth[i] = regs[i].GetBounds(g).Width; }
                else
                { fCharWidth[i] = regs[i].GetBounds(g).Height; }
                fTotalWidth += fCharWidth[i] + fIntervalWidth;
            }
            fTotalWidth -= fIntervalWidth;
            return fTotalWidth;
        }

        /// <summary>
        /// 求出每个字符的所在的点，以及相对于中心的角度
        ///1．  通过字符长度，求出字符所跨的弧度；
        ///2．  根据字符所跨的弧度，以及字符起始位置，算出字符的中心位置所对应的角度；
        ///3．  由于相对中心的角度已知，根据三角公式很容易算出字符所在弧上的点，如下图所示；
        ///4．  根据字符长度以及间隔距离，算出下一个字符的起始角度；
        ///5．  重复1直至整个字符串结束。
        /// </summary>
        /// <param name="CharWidth"></param>
        /// <param name="recChars"></param>
        /// <param name="CharAngle"></param>
        /// <param name="StartAngle"></param>
        private static void ComputeCharPos(float[] CharWidth, PointF[] recChars, double[] CharAngle, double StartAngle)
        {
            double fSweepAngle, fCircleLength;
            fCircleLength = NewRect.Width * Math.PI;
            for (int i = 0; i < CharWidth.Length; i++)
            {
                fSweepAngle = CharWidth[i] * 360 / fCircleLength;
                CharAngle[i] = StartAngle + fSweepAngle / 2;
                if (CharAngle[i] < 270f)
                {
                    recChars[i] = new PointF(
                         NewRect.X + NewRect.Width / 2
                         - (float)(NewRect.Width / 2 *
                         Math.Sin(Math.Abs(CharAngle[i] - 270) * Math.PI / 180)),
                         NewRect.Y + NewRect.Width / 2
                         - (float)(NewRect.Width / 2 * Math.Cos(
                         Math.Abs(CharAngle[i] - 270) * Math.PI / 180)));
                }
                else
                {
                    recChars[i] = new PointF(
                           NewRect.X + NewRect.Width / 2
                           + (float)(NewRect.Width / 2 *
                           Math.Sin(Math.Abs(CharAngle[i] - 270) * Math.PI / 180)),
                           NewRect.Y + NewRect.Width / 2
                           - (float)(NewRect.Width / 2 * Math.Cos(
                           Math.Abs(CharAngle[i] - 270) * Math.PI / 180)));
                }
                fSweepAngle = (CharWidth[i] + _letterspace) * 360 / fCircleLength;
                StartAngle += fSweepAngle;
            }
        }
        /// <summary>
        /// 绘制每个字符
        /// </summary>
        /// <param name="g"></param>
        /// <param name="_text"></param>
        /// <param name="_angle"></param>
        /// <param name="text_Point"></param>
        /// <param name="text_Font"></param>
        /// <param name="myPen"></param>
        private static void DrawRotatedText(Graphics g, string _text, float _angle, PointF text_Point, Font text_Font, Pen myPen)
        {
            StringFormat sf = new StringFormat();
            sf.Alignment = StringAlignment.Center;
            sf.LineAlignment = StringAlignment.Center;
            GraphicsPath gp = new GraphicsPath(System.Drawing.Drawing2D.FillMode.Winding);
            int x = (int)text_Point.X;
            int y = (int)text_Point.Y;
            gp.AddString(_text, text_Font.FontFamily, (int)text_Font.Style, text_Font.Size, new Point(x, y), sf);
            Matrix m = new Matrix();
            m.RotateAt(_angle, new PointF(x, y));
            g.Transform = m;
            g.DrawPath(myPen, gp);
            g.FillPath(new SolidBrush(Color.Red), gp);
        }
        public enum Char_Direction
        {
            Center = 0,
            OutSide = 1,
            ClockWise = 2,
            AntiClockWise = 3,
        }
    }

 

3、具体效果

 

原文地址：C#生成电子印章源码_weixin_30780221的博客-CSDN博客