点点细雨的原创博文！供各位在编程之路的同学们参考~
本人博文允许转载，但请在文章显著位置注明转载出处以及原文链接，谢谢合作！
其实这个也不算是这个项目里用的啦，以前老师给推荐的，很好用哦！
页面的图像按钮 -> 链接地址为验证码的页面
-> 验证码返回一个随机生成的图片到图像按钮并将图片的数字保存在SESSION里
->页面通过文本框用户输入中的数值与SESSION比较
-> 进行判断
源代码：
using System;
using
System.Collections;
using
System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using
System.Web.Security;
using
System.Web.UI;
using
System.Web.UI.HtmlControls;
using
System.Web.UI.WebControls;
using
System.Web.UI.WebControls.WebParts;
using
System.Xml.Linq;
using
System.Drawing;
namespace
AnboSchoolServeSystem.Admin
{
public partial class VerityCode :
System.Web.UI.Page
{
protected
void Page_Load(object sender, EventArgs e)
{
this.CreateImage(this.GenerateNumber(4));
}
private
void CreateImage(string checkCode)
{
int iwidth =
(int)(checkCode.Length * 15);
System.Drawing.Bitmap image =
new System.Drawing.Bitmap(iwidth, 20);
Graphics g =
Graphics.FromImage(image);
g.Clear(Color.White);
Color[] c = { Color.Black,
Color.Red, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown,
Color.DarkCyan, Color.Purple };
string[] font = { "Verdana",
"Microsoft Sans Serif", "Comic Sans MS", "Arial", "宋体"
};
Random rand = new
Random();
for (int i = 0; i
< 50; i++)
{
int x = rand.Next(image.Width);
int y = rand.Next(image.Height);
g.DrawRectangle(new Pen(Color.LightGray, 0), x,
y, 1, 1);
}
for (int i = 0; i
< checkCode.Length; i++)
{
int cindex = rand.Next(7);
int findex = rand.Next(5);
Font f = new System.Drawing.Font(font[findex],
12, System.Drawing.FontStyle.Bold);
Brush b = new
System.Drawing.SolidBrush(c[cindex]);
int ii = 4;
if ((i + 1) % 2 == 0)
{
ii =
2;
}
g.DrawString(checkCode.Substring(i, 1), f, b, 3
+ (i * 12), ii);
}
g.DrawRectangle(new
Pen(Color.Black, 0), 0, 0, image.Width - 1, image.Height -
1);
System.IO.MemoryStream ms =
new System.IO.MemoryStream();
image.Save(ms,
System.Drawing.Imaging.ImageFormat.Jpeg);
Response.ClearContent();
Response.ContentType =
"Image/Jpeg";
Response.BinaryWrite(ms.ToArray());
g.Dispose();
image.Dispose();
}
public
string GenerateNumber(int codeLength)
{//,W,E,R,T,Y,U,I,P,L,K,J,H,G,F,S,A,Z,X,C,V,B,N,M
string Vchar =
"1,2,3,4,5,6,7,8,9";
string[] VcArray =
Vchar.Split(',');
string VNum =
"";
Random random = new
Random();
for (int i = 0; i
<= codeLength; i++)
{
int iNum = 0;
while ((iNum = Convert.ToInt32(VcArray.Length *
random.NextDouble())) == VcArray.Length)
{
iNum =
Convert.ToInt32(VcArray.Length * random.NextDouble());
}
VNum += VcArray[iNum];
}
Session["VerifyCode"] =
VNum.ToString().Trim();
return VNum;
}
}
}
------------------------------------------------------------------------------
页面源代码片段：
<tr>
<td
height="35" class="style1" ><span
class="login_txt">验证码：</span></td>
<td
height="35" colspan="2" class="top_hui_text">
<asp:TextBox
ID="txtVerityCode"
runat="server"
ontextchanged="txtVerityCode_TextChanged"></asp:TextBox>
<asp:ImageButton
ID="ImageButton1" runat="server" ImageUrl="~/Admin/VerityCode.aspx"
ToolTip="点击切换" />
</td>
cs文件中的事件：
protected void
btnLogin_Click(object sender, EventArgs e)
{
string
username=txtName.Text.ToString().Trim();
string
userpwd=txtPwd.Text.ToString().Trim();
string
code = Session["VerifyCode"].ToString();
if
(txtVerityCode.Text.Trim() == "")
{
Page.ClientScript.RegisterStartupScript(this.GetType(), "lb",
"<script
language='javascript'>alert('验证码输入不能为空！');</script>",
false);
}
else if
(txtVerityCode.Text.Trim() != code)
{
Page.ClientScript.RegisterStartupScript(this.GetType(), "lb",
"<script
language='javascript'>alert('验证码输入错误，请重新输入！');</script>",
false);
}
else
{
users
users= usersBll.GetUsersByNameAndPwd(username,
FormsAuthentication.HashPasswordForStoringInConfigFile(userpwd,
"SHA1"));
if (users != null)
{
//Session.Add("CurrentUser", admin);
//if (LogsManager.AddLogs(admin.UserID))
//{
Response.Redirect("index.aspx");
Session["users_id"] = users.Users_id;
if
(users.Users_power == true)
{
Session["superadmin"] =
true;
}
//}
//else
//{
//
Session.Abandon();
//
Page.RegisterStartupScript("err2",
"<script>alert('日志写入失败，请重试！');</script>");
//}
}
else
{
Page.RegisterStartupScript("err3",
"<script>alert('密码或者用户名不正确，请重新输入！');document.getElementByIdx_x('txtUserName').select();document.getElementByIdx_x('txtUserName').focus();</script>");
return;
}
}
}
protected void txtVerityCode_TextChanged(object
sender, EventArgs e)
{
string
code = Session["VerifyCode"].ToString();
if
(txtVerityCode.Text.Trim() != code)
{
Page.ClientScript.RegisterStartupScript(this.GetType(), "lb",
"<script
language='javascript'>alert('验证码输入错误，请重新输入！');</script>",
false);
}
}