驗證碼看不清換一組 
寫一個類
public class ValidateCode
{
public ValidateCode()
{
}
/// <summary>
/// 驗證碼的最大長度
/// </summary>
public int MaxLength
{
get { return 10; }
}
/// <summary>
/// 驗證碼的最小長度
/// </summary>
public int MinLength
{
get { return 1; }
}
/// <summary>
/// 生成驗證碼
/// </summary>
/// <param name="length">指定驗證碼的長度</param>
/// <returns></returns>
public string CreateValidateCode(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;
}
//生成隨機數字
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);
}
//抽取隨機數字
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));
}
//生成驗證碼
for (int i = 0; i < length; i++)
{
validateNumberStr += validateNums[i].ToString();
}
return validateNumberStr;
}
/// <summary>
/// 創建驗證碼的圖片
/// </summary>
/// <param name="containsPage">要輸出到的page對象</param>
/// <param name="validateNum">驗證碼</param>
public byte[] CreateValidateGraphic(string validateCode)
{
Bitmap image = new Bitmap((int)Math.Ceiling(validateCode.Length * 12.0), 22);
Graphics g = Graphics.FromImage(image);
try
{
//生成隨機生成器
Random random = new Random();
//清空圖片背景色
g.Clear(Color.White);
//畫圖片的干擾線
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));
LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height),
Color.Blue, Color.DarkRed, 1.2f, true);
g.DrawString(validateCode, font, brush, 3, 2);
//畫圖片的前景干擾點
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()));
}
//畫圖片的邊框線
g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
//保存圖片數據
MemoryStream stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
//輸出圖片流
return stream.ToArray();
}
finally
{
g.Dispose();
image.Dispose();
}
}
/// <summary>
/// 得到驗證碼圖片的長度
/// </summary>
/// <param name="validateNumLength">驗證碼的長度</param>
/// <returns></returns>
public static int GetImageWidth(int validateNumLength)
{
return (int)(validateNumLength * 12.0);
}
/// <summary>
/// 得到驗證碼的高度
/// </summary>
/// <returns></returns>
public static double GetImageHeight()
{
return 22.5;
}
}
然後在controller中寫到
public ActionResult GetValidateCode()
{
MyEbook.Models.ValidateCode vCode =new MyEbook.Models.ValidateCode ();
string code = vCode.CreateValidateCode(5);
Session["ValidateCode"] = code;
byte[] bytes = vCode.CreateValidateGraphic(code);
return File(bytes, @"image/jpeg");
}
然後在view中頁面調用
<img id="imgCode" src="../MyEbook/GetValidateCode" style="cursor: pointer; vertical-align: middle" alt="ValidateCode" />
最後單擊無刷新更換驗證碼(使用jquery)
$("#imgCode").click(function() { this.src = "../MyEbook/GetValidateCode?time" + new Date().getTime(); });//後面一定new一個date不然不會進行換組
驗證碼同步(防止第一次打開頁面時不顯示session驗證碼)
首先
在actionresult中寫一個
public ActionResult GetJsonData()//get data(獲取數據)
{
return this.Json(Session["ValidateCode"]);
}
然後
在頁面中寫點擊驗證碼圖片的事件
$.ajax({url:”GetJsonData”,type:”post”,dataType:”json”,success:showResult})
function showResult(result) { $("#hCode").val(result.toString()); };
即可第一次加載時session有值