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);
}
}
