如何截取 页面上的验证码图片？
比如 要拉取别的网站上的 验证码，然后显示在自己网页上。
怎么能获取到他的图片的地址呢？ 我看页面源代码关于验证码这块如下：
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
//生成验证码
string temp = this.GetCode(4);
HttpCookie cookie = new HttpCookie("yzm");
cookie.Value = temp;
Response.Cookies.Add(cookie);
//画图
this.GetCheckCodeImage(temp);
}
}
//产生随机字符串
private string GetCode(int num)
{
string[] source ={ "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"};
string code = "";
Random rd = new Random();
for (int i = 0; i < num; i++)
{
code += source[rd.Next(0, source.Length)];
}
Session["ValidateCode"] = code;//将字符串保存到Session中，以便需要时进行验证
return code;
}
#region 验证码
/// <summary>
/// 生成验证码
/// </summary>
/// <param name="checkCode"></param>
private void GetCheckCodeImage(string checkCode)
{
if (checkCode == null
[解决办法]
checkCode.Trim() == String.Empty) return;
System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)),25);
Graphics g = Graphics.FromImage(image);
try
{
Random random = new Random(); //生成随机生成器
g.Clear(Color.White); //清空图片背景色
for (int i = 0; i < 5; i++) //画图片的背景噪音线
{
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
[解决办法]
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 < 60; 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();
}
}
#endregion
<script type="text/javascript" src="JS/jquery-1.4.4.js"></script>
<script type="text/javascript">
$(function() {
var src = "http://passport.csdn.net/ShowExPwd.aspx?temp=(new Date().getTime().toString(36))";
$("#validate").attr("src", src);
});
</script>
<img id="validate" />
