我把生成验证码与生成验证码图片封装成一个静态方法，放到ValidateCode类里
/// <summary>
/// 生成验证码的类
/// </summary>
public static class ValidateCode
{
/// <summary>
/// 生成验证码
/// </summary>
/// <param name="length">指定验证码的长度</param>
/// <returns></returns>
public static string CreateValidateNumber(int length)
{
int[] randMembers = new int[length];
int[] validateNums = new int[length];
string validateNumberStr = "";
//生成起始序列值
int seekSeek = unchecked((int)DateTime.Now.Ticks);
Random seekRand = new Random(seekSeek);
int beginSeek = (int)seekRand.Next(0, Int32.MaxValue - length * 10000);
int[] seeks = new int[length];
for (int i = 0; i < length; i++)
{
beginSeek += 10000;
seeks[i] = beginSeek;
}
//生成随机数字
for (int i = 0; i < length; i++)
{
Random rand = new Random(seeks[i]);
int pownum = 1 * (int)Math.Pow(10, length);
randMembers[i] = rand.Next(pownum, Int32.MaxValue);
}
//抽取随机数字
for (int i = 0; i < length; i++)
{
string numStr = randMembers[i].ToString();
int numLength = numStr.Length;
Random rand = new Random();
int numPosition = rand.Next(0, numLength - 1);
validateNums[i] = Int32.Parse(numStr.Substring(numPosition, 1));
}
//生成验证码
for (int i = 0; i < length; i++)
{
validateNumberStr += validateNums[i].ToString();
}
return validateNumberStr;
}
/// <summary>
/// 创建验证码的图片
/// </summary>
/// <param name="containsPage">要输出到的page对象</param>
/// <param name="validateNum">验证码</param>
public static void CreateValidateGraphic(Page containsPage, string validateNum)
{
Bitmap image = new Bitmap((int)Math.Ceiling(validateNum.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);
//画图片的干扰线
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", 14, (FontStyle.Bold | FontStyle.Italic));
LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(validateNum, font, brush, 3, 2);
//画图片的前景干扰点
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);
//保存图片数据
MemoryStream stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
//输出图片
containsPage.Response.Clear();
containsPage.Response.ContentType = "image/jpeg";
containsPage.Response.BinaryWrite(stream.ToArray());
}
finally
{
g.Dispose();
image.Dispose();
}
}
}
下面的介绍才是重点哦，在页面上放控件把点击刷新脚本。
网上GOOGL一下很多这样的介绍：
html中加入<img src="Default2.aspx" id="yzm" alt="点击刷新" />
在</head>之前一行加入javascript脚本语言如下(当然写在JS文件里面更好):
<script type="text/javascript">
function reloadcode(){
document.getElementById("yzm").src ="CheckCode.aspx";
}
</script>
其实试了就知道不行的。正确的是：
<img id="Image1" src="ValidateImage.aspx" style="cursor:pointer" οnmοuseup="RefreshImage()" alt="点击重刷新"/>
<script language ="javascript" type="text/javascript" >
function RefreshImage()
{
var el =document.getElementById("Image1");
el.src=el.src+'?';//这个特别重要
}
</script>
