62,046
社区成员
发帖
与我相关
我的任务
分享
protected void Page_Load(object sender, EventArgs e)
{
CreateCheckCodeImage(GenerateCheckCode());
}
private string GenerateCheckCode() //绘制4个随机数或字母
{
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();
}
Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
return checkCode;
}
private void CreateCheckCodeImage(string checkCode)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
System.Drawing.Bitmap image = new System.Drawing.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 < 2; 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.Black), x1, y1, x2, y2);
}
Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold));
System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.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);
System.IO.MemoryStream ms = new System.IO.MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/Gif";
Response.BinaryWrite(ms.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
//用户名和密码框,你自己写下
验证码:<asp:TextBox ID="txtCheckCode" runat="server"></asp:TextBox>
<asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="CheckCode.aspx" Height="20px" Width="80px" BorderStyle="None" />
<asp:Label ID="lblMessage" runat="server" Text=""></asp:Label>
<br />
<br />
<asp:Button ID="btnLogin" runat="server" Height="37px" Text="登录"
Width="123px" onclick="btnRegister_Click" />
protected void btnLogin_Click(object sender, EventArgs e)
{
if (Request.Cookies["CheckCode"] == null)
{
lblMessage.Text = "您的浏览器设置已被禁用 Cookies,您必须设置浏览器允许使用 Cookies 选项后才能使用本系统。";
lblMessage.Visible = true;
return;
}
if (String.Compare(Request.Cookies["CheckCode"].Value, this.txtCheckCode.Text, true) == 0)
{
//这里就是你调用登录的方法,在这里写就对了
lblMessage.Text = "验证码正确,恭喜啊。";
}
else {
lblMessage.Text = "验证码错误,请输入正确的验证码。";
}
}
<script type="text/javascript">
function show(im)
{
im.src="ValidateCode1.aspx?"+new Date;
}
</script>
<img src="ValidateCode1.aspx" onclick ="show(this)" /></td>
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Drawing;
using System.ComponentModel;
using System.Web.SessionState;
public partial class ValidateCode1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
string randomcode = this.CreateRandomCode(4);
Session["CheckCode"] = randomcode;
//ViewState["ValidateCode"] = randomcode;
this.CreateImage(randomcode);
}
private string CreateRandomCode(int length)
{
int rand;
char code;
string randomcode = String.Empty;
//生成一定长度的验证码
System.Random random = new Random();
for (int i = 0; i < length; i++)
{
rand = random.Next();
if (rand % 3 == 0)
{
code = (char)('A' + (char)(rand % 26));
}
else
{
code = (char)('0' + (char)(rand % 10));
}
randomcode += code.ToString();
}
return randomcode;
}
/// <summary>
/// 创建随机码图片
/// </summary>
/// <param name="randomcode">随机码</param>
private void CreateImage(string randomcode)
{
int randAngle = 45; //随机转动角度
int mapwidth = (int)(randomcode.Length * 23);
Bitmap map = new Bitmap(mapwidth, 28);//创建图片背景
Graphics graph = Graphics.FromImage(map);
graph.Clear(Color.White);//清除画面,填充背景
graph.DrawRectangle(new Pen(Color.White, 0), 0, 0, map.Width - 1, map.Height - 1);//画一个边框
//graph.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;//模式
Random rand = new Random();
//背景噪点生成
Pen blackPen = new Pen(Color.LightGray, 0);
for (int i = 0; i < 50; i++)
{
int x = rand.Next(0, map.Width);
int y = rand.Next(0, map.Height);
graph.DrawRectangle(blackPen, x, y, 1, 1);
}
//验证码旋转,防止机器识别
char[] chars = randomcode.ToCharArray();//拆散字符串成单字符数组
//文字距中
StringFormat format = new StringFormat(StringFormatFlags.NoClip);
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
//定义颜色
Color[] c = { Color.Black, Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };
//定义字体
string[] font = { "Verdana", "Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体" };
for (int i = 0; i < chars.Length; i++)
{
int cindex = rand.Next(7);
int findex = rand.Next(5);
Font f = new System.Drawing.Font(font[findex], 13, System.Drawing.FontStyle.Bold);//字体样式(参数2为字体大小)
Brush b = new System.Drawing.SolidBrush(c[cindex]);
Point dot = new Point(16, 16);
//graph.DrawString(dot.X.ToString(),fontstyle,new SolidBrush(Color.Black),10,150);//测试X坐标显示间距的
float angle = rand.Next(-randAngle, randAngle);//转动的度数
graph.TranslateTransform(dot.X, dot.Y);//移动光标到指定位置
graph.RotateTransform(angle);
graph.DrawString(chars[i].ToString(), f, b, 1, 1, format);
//graph.DrawString(chars[i].ToString(),fontstyle,new SolidBrush(Color.Blue),1,1,format);
graph.RotateTransform(-angle);//转回去
graph.TranslateTransform(2, -dot.Y);//移动光标到指定位置
}
//生成图片
System.IO.MemoryStream ms = new System.IO.MemoryStream();
map.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
Response.ClearContent();
Response.ContentType = "image/gif";
Response.BinaryWrite(ms.ToArray());
graph.Dispose();
map.Dispose();
}
}