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  • .NET验证码

    转载的验证码,微改后验证码如下:

    CheckCode.aspx.cs代码如下:

    protected void Page_Load(object sender, EventArgs e)
            {
                this.CreateCheckCodeImage(GenerateCheckCode());
            }
    
            private string GenerateCheckCode()
            {
                int number;
                char code;
                string checkCode = string.Empty;
    
                Random random = new Random();
    
                for (int i = 0; i < 5; i++)
                {
                    number = random.Next();
    
                    if (number % 2 == 0)
                        code = (char)('0' + (char)(number % 10));
                    else
                        code = (char)('A' + (char)(number % 26));
                    checkCode += code.ToString();//获取编码数
                }
                Session["CheckCode"] = checkCode;
                return checkCode;
            }
    
            private void CreateCheckCodeImage(string checkCode)
            {
                if (checkCode == null || checkCode.Trim() == string.Empty)
                    return;
                Bitmap image = new Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
                Graphics g = Graphics.FromImage(image);
    
                try
                {
                    //生成随机生成器
                    Random random = new Random();
    
                    //清空图片背景色
                    g.Clear(Color.White);
    
                    //画图片的背景噪音线
                    for (int i = 0; i < 25; i++)
                    {
                        int x1 = random.Next(image.Width);
                        int x2 = random.Next(image.Width);
                        int y1 = random.Next(image.Height);
                        int y2 = random.Next(image.Height);
    
                        g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                    }
    
                    Font font = new Font("Arial", 12, (FontStyle.Bold | FontStyle.Italic | FontStyle.Underline));
    
                    LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
                    g.DrawString(checkCode, font, brush, 2, 2);
    
                    //画图片的前景噪音点
                    for (int i = 0; i < 100; i++)
                    {
                        int x = random.Next(image.Width);
                        int y = random.Next(image.Height);
    
                        image.SetPixel(x, y, Color.FromArgb(random.Next()));
                    }
    
                    //画图片的边框线
                    g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
    
                    MemoryStream ms = new MemoryStream();
                    image.Save(ms, ImageFormat.Gif);
                    Response.ClearContent();
                    Response.ContentType = "image/Gif";
                    Response.BinaryWrite(ms.ToArray());
                }
                finally
                {
                    g.Dispose();
                    image.Dispose();
                }
            }
    

     调用CheckCode.aspx文件代码如下:

    <td class="tbleft">
         <asp:TextBox ID="txtUserCoder" runat="server"></asp:TextBox>
    
     <img id="CodeImg" src="WebCode.aspx" onclick="document.getElementById('CodeImg').src='WebCode.aspx?tmp='+Math.random()" style="cursor:pointer;"/>
    
    </td>
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  • 原文地址:https://www.cnblogs.com/biye/p/2666098.html
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