script language="javascript">
function changeImg() {
$("#imgCheckNo").attr("src", "ValidateImage.aspx?r=" + getRandom(999));
}
function getRandom(n) { return Math.floor(Math.random() * n + 1) }
/script>
div>
img id="imgCheckNo" src="ValidateImage.aspx" style="border-color: #000000; border-width: 1px;border-style: Solid">
span onclick="changeImg();">看不清?換一張/span>
/div>
div>
div class="labelCss">驗證碼：/div>
div>
asp:TextBox ID="tbxCheckNo" runat="server" CssClass="tbxCss">/asp:TextBox>
/div>
div>
asp:Button ID="btnSubmit" runat="server" Text="立即注冊" OnClick="btnSubmit_Click" />
/div>
public partial class ValidateImage : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
this.CreateCheckCodeImage(RndNum());
}
/// summary>生成驗證碼
/// /summary>
/// returns>/returns>
private string RndNum()
{
int number;
char code;
string checkCode = String.Empty;
System.Random random = new Random();
for (int i = 0; i 4; 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("yzmcode", checkCode));
return checkCode;
}
/// summary>向頁面生成驗證碼Gif圖片
/// /summary>
/// param name="checkCode">/param>
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
{
//生成隨機生成器
Random random = new Random();
//清空圖片背景色
g.Clear(Color.White);
//畫圖片的背景噪音線
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 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);
//畫圖片的前景噪音點
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);
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();
}
}
}
