public VerifyImageInfo GenerateImage(string code, int width, int height, Color bgcolor, int textcolor) { VerifyImageInfo verifyimage = new VerifyImageInfo(); verifyimage.ImageFormat = ImageFormat.Jpeg; verifyimage.ContentType = "image/pjpeg"; // 直接指定尺寸, 而不使用外部参数中的建议尺寸 width = 100; height = 32; Bitmap bitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb); Graphics g = Graphics.FromImage(bitmap); g.SmoothingMode = SmoothingMode.HighSpeed; g.Clear(bgcolor); int fixedNumber = textcolor == 2 ? 60 : 0; Pen linePen = new Pen(Color.FromArgb(Next(50) + fixedNumber, Next(50) + fixedNumber, Next(50) + fixedNumber), 1); SolidBrush drawBrush = new SolidBrush(Color.FromArgb(Next(100), Next(100), Next(100))); for (int i = 0; i < 3; i++) { g.DrawArc(linePen, Next(20) - 6, Next(20) - 6, Next(width) + 6, Next(height) + 6, Next(-100, 100), Next(-200, 200)); } Graphics charg = Graphics.FromImage(charbmp); float charx = -18; for (int i = 0; i < code.Length; i++) { m.Reset(); m.RotateAt(Next(50) - 25, new PointF(Next(3) + 7, Next(3) + 7)); charg.Clear(Color.Transparent); charg.Transform = m; //定义前景色为黑色 drawBrush.Color = Color.Black; charx = charx + 18 + Next(5); PointF drawPoint = new PointF(charx, 2.0F); charg.DrawString(code[i].ToString(), fonts[Next(fonts.Length - 1)], drawBrush, new PointF(0, 0)); charg.ResetTransform(); g.DrawImage(charbmp, drawPoint); } drawBrush.Dispose(); g.Dispose(); charg.Dispose(); verifyimage.Image = bitmap; return(verifyimage); }
protected void Page_Load(object sender, EventArgs e) { Context.Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache); string vercode = CreateAuthStr(4, false); Session["vercode"] = vercode; VerifyImage verifyimg = new VerifyImage(); VerifyImageInfo verifyimginfo = verifyimg.GenerateImage(vercode, 120, 30, System.Drawing.Color.White, 2); System.Drawing.Bitmap image = verifyimginfo.Image; System.Web.HttpContext.Current.Response.ContentType = verifyimginfo.ContentType; image.Save(this.Response.OutputStream, verifyimginfo.ImageFormat); }