图片掩码+水印

  //图片验证码
        private void button3_Click(object sender, EventArgs e)
        {
            //定义一个数值的字符串
            string sourceCode = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz";
            string code = "";
            //随机数获取
            Random random = new Random();
            for (int i = 0; i < 6; i++)
            {
                int flag = random.Next(0, 61);
                code += sourceCode.Substring(flag, 1);
            }
            //定义一个画板
            Bitmap bitmap = new Bitmap(160, 50);//设置的是高和宽  
            //定义画布
            Graphics graphics = Graphics.FromImage(bitmap);
            //在画布上设置背景颜色
            graphics.FillRectangle(new SolidBrush(Color.Red), 0, 0, 160, 50);
            //设置字体
            Font font = new Font(new FontFamily("微软雅黑"), 15.0f);

            //画干扰线
            for (int i = 0; i < 6; i++)
            {
                Pen pen = new Pen(new SolidBrush(Color.Yellow), 1);
                Point point = new Point(random.Next(0, 160), random.Next(2, 80));
                Point point1 = new Point(random.Next(0, 160), random.Next(2, 90));
                graphics.DrawLine(pen, point, point1);
            }
            //画图
            graphics.DrawString(code, font, new SolidBrush(Color.Green), new PointF(10, 10));
            //保存图片
            using (FileStream fs = new FileStream(@"E:code.png", FileMode.Create, FileAccess.ReadWrite))
            {
                bitmap.Save(fs, ImageFormat.Png);
            }
        }
        //spire进行水印的添加
        private void button4_Click(object sender, EventArgs e)
        {
            Spire.Doc.Document document = new Spire.Doc.Document(@"E:1.八维学院2.教学8.专高41.教学大纲9.C#高级特性大纲（最新版本）-New.docx");
            Spire.Doc.TextWatermark text = new Spire.Doc.TextWatermark("仅限内部使用");
            document.Watermark = text;
            text.FontName = "微软雅黑";//设置字体
            text.FontSize = 20.0f;//设置文字大小
            text.Color = Color.Green;//设置颜色
         
            document.SaveToFile(@"E:1.八维学院2.教学8.专高41.教学大纲9.C#高级特性大纲（最新版本）-New2.docx");
        }