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//随机实例化
Random ran = new Random();
int number;
char code1;
//取五个数
for (int i = 0; i < 5; i++)
{
number = ran.Next();
if (number % 2 == 0)
code1 = (char)('0' + (char)(number % 10));
else
code1 = (char)('A' + (char)(number % 26)); //转化为字符
this.code += code1.ToString();
}
this.gragh = System.Drawing.Graphics.FromImage(this.bitmap); //将位图加载到封装的位图
Font font = new Font("宋体", 25f); //定义文字格式大小
this.gragh.Clear(System.Drawing.Color.Yellow); //图片颜色填充
SolidBrush brush = new SolidBrush(Color.FromArgb(10, 10, 10)); //字体颜色填充
this.gragh.DrawString(this.code, font, brush, 0, 0); //将字符串画到grash图中。。
this.bitmap.Save(this.ms, System.Drawing.Imaging.ImageFormat.Gif); //保存到内存而且为gif图片
this.pictureBox1.Image = Image.FromStream(this.ms);
this.ms.Close();
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;
public partial class Default2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this.CreateCheckCodeImage(GenerateCheckCode());
}
//产生随机数的函数
private string GenerateCheckCode()
{
int number;
char code;
//空字符串且为只读属性
string checkCode = String.Empty;
//新建一个随机数产生器
System.Random random = new Random();
for (int i = 0; i < 5; i++)
{ //随机产生一个整数
number = random.Next();
//如果随机数是偶数 取余
if (number % 2 == 0)
code = (char)('0' + (char)(number % 10));
else
//如果随机数是奇数 选择从[A-Z]
code = (char)('A' + (char)(number % 26));
//5个字符的组合
checkCode += code.ToString();
}
//将字符串checkCode写入Cookies并且返回字符串 checkCode
Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));
return checkCode;
}
//建立一个随机图形
private void CreateCheckCodeImage(string checkCode)
{
if (checkCode == null || checkCode.Trim() == String.Empty)
return;
//建立一个位图文件 确立长宽
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 < 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);
}
//把产生的随机数以字体的形式写入画面
Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
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();
}
}
}
//你可以用一个label窗体,用其文本窗体显示随机数,然后用textbox的文本值与lable的text值做比较
下面是代码的核心部分你看一下吧,对你可能有点帮助
private static char[] constant ={'0','1','2','3','4','5','6','7','8','9',
'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'
};
public Form1()
{
InitializeComponent();
}
public static string GetRandomNumber(int Len)
{
System.Text.StringBuilder newRandom = new StringBuilder(62);
Random rd = new Random();
for (int i = 0; i < Len; i++)
{
newRandom.Append(constant[rd.Next(62)]);
}
return newRandom.ToString();
}
private void Form1_Load(object sender, EventArgs e)
{
this.label1.Text = GetRandomNumber(5);
}
private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
{
this.label1.Text = GetRandomNumber(5);
}