1、創建一個驗證類，裏面有生成驗證碼的兩個方法。
namespace YTJWGL_Common
{
public class ValidatorCodeTools
{
#region 生成校驗碼圖片
public ValidatorCodeTools()
{
}
/// <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="validateCode">驗證碼內容</param>
/// <returns></returns>
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;
}
#endregion
}
}2、CreateValidateCode方法生成驗證碼內容，對應圖片中的形如“54361”這樣的數字。而CreateValidateGraphic該方法接收一個參數，把參數中的驗證碼轉換爲圖片顯示。在BLL層有兩個方法：
namespace YTJWGL_Bll
{
public class AdminService : BaseService<YTJWGL_Admin>, IAdminService
{
/// <summary>
/// 生成驗證碼數字
/// </summary>
/// <param name="id">驗證碼位數，默認爲5</param>
/// <returns></returns>
public string NewValidateCode(int id = 5)
{
ValidatorCodeTools obj = new ValidatorCodeTools();
return obj.CreateValidateCode(5);
}
/// <summary>
/// 驗證碼圖片
/// </summary>
/// <param name="code"></param>
/// <returns></returns>
public byte[] NewValidateCodeGraphic(string code)
{
ValidatorCodeTools obj = new ValidatorCodeTools();
return obj.CreateValidateGraphic(code);
}
}
}3、新建一個Action:
#region Admin
public ActionResult GetValidatorGraphics()
{
string code = _adminService.NewValidateCode();
Session["ValidatorCode"] = code;
byte[] graphic = _adminService.NewValidateCodeGraphic(code);
return File(graphic, @"image/jpeg");
}
#endregion在Action中調用我們剛纔在BLL層定義 的兩個方法，返回這張驗證碼圖片。因爲http是無連接的，這個action僅僅響應用戶一次訪問請求，當用戶點擊登錄後會將填寫的驗證碼發送到服務器， 而這已經是第二次訪問請求了，所以需要用Session用來保存剛纔發往客戶端的驗證碼。
那麼接下來就在視圖中顯示了，請繼續向下閱讀；
4.只需要使用<img>標籤的src屬性訪問我們剛纔的action。生成的效果如下：
<img id="valiCode" [email protected]("GetValidatorGraphics", "safe") alt=" " />
<script type="text/javascript">
//當點擊圖片時，刷新驗證碼
$(function () {
$("#valiCode").bind("click", function () {
this.src = "@Url.Action("GetValidatorGraphics", "Frame")?time=" + (new Date()).getTime();
});
});
</script>