1. 处理程序文件 ValidateImageHandler.ashx代码如下
1 <% @ WebHandler Language = " C# " Class = " ValidateImageHandler " %> 2 3 using System; 4 using System.Web; 5 using System.Web.SessionState; 6 using System.Drawing; 7 using System.Drawing.Imaging; 8 using System.Text; 9 10 /// 11 /// ValidateImageHandler 生成网站验证码功能12 /// 13 public class ValidateImageHandler : IHttpHandler, IRequiresSessionState 14 { 15 int intLength = 5 ; // 长度 16 string strIdentify = " Identify " ; // 随机字串存储键值,以便存储到Session中 17 public ValidateImageHandler() 18 { 19 } 20 21 /// 22 /// 生成验证图片核心代码23 /// 24 /// 25 public void ProcessRequest(HttpContext hc) 26 { 27 // 设置输出流图片格式 28 hc.Response.ContentType = " image/gif " ; 29 30 Bitmap b = new Bitmap( 200 , 60 ); 31 Graphics g = Graphics.FromImage(b); 32 g.FillRectangle( new SolidBrush(Color.YellowGreen), 0 , 0 , 200 , 60 ); 33 Font font = new Font(FontFamily.GenericSerif, 48 , FontStyle.Bold, GraphicsUnit.Pixel); 34 Random r = new Random(); 35 36 // 合法随机显示字符列表 37 string strLetters = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890 " ; 38 StringBuilder s = new StringBuilder(); 39 40 // 将随机生成的字符串绘制到图片上 41 for ( int i = 0 ; i < intLength; i ++ ) 42 { 43 s.Append(strLetters.Substring(r.Next( 0 , strLetters.Length - 1 ), 1 )); 44 g.DrawString(s[s.Length - 1 ].ToString(), font, new SolidBrush(Color.Blue), i * 38 , r.Next( 0 , 15 )); 45 } 46 47 // 生成干扰线条 48 Pen pen = new Pen( new SolidBrush(Color.Blue), 2 ); 49 for ( int i = 0 ; i < 10 ; i ++ ) 50 { 51 g.DrawLine(pen, new Point(r.Next( 0 , 199 ), r.Next( 0 , 59 )), new Point(r.Next( 0 , 199 ), r.Next( 0 , 59 ))); 52 } 53 b.Save(hc.Response.OutputStream, ImageFormat.Gif); 54 hc.Session[strIdentify] = s.ToString(); // 先保存在Session中,验证与用户输入是否一致 55 hc.Response.End(); 56 57 } 58 59 /// 60 /// 表示此类实例是否可以被多个请求共用(重用可以提高性能)61 /// 62 public bool IsReusable 63 { 64 get 65 { 66 return true ; 67 } 68 } 69 } 70 2. 前台页面代码
1 < asp:Login ID = " Login1 " runat = " server " BackColor = " #EFF3FB " BorderColor = " #B5C7DE " BorderPadding = " 4 " BorderStyle = " Solid " BorderWidth = " 1px " Font - Names = " Verdana " Font - Size = " 0.8em " ForeColor = " #333333 " OnAuthenticate = " Login1_Authenticate " > 2 < TitleTextStyle BackColor = " #507CD1 " Font - Bold = " True " Font - Size = " 0.9em " ForeColor = " White " /> 3 < InstructionTextStyle Font - Italic = " True " ForeColor = " Black " /> 4 < TextBoxStyle Font - Size = " 0.8em " /> 5 < LoginButtonStyle BackColor = " White " BorderColor = " #507CD1 " BorderStyle = " Solid " BorderWidth = " 1px " 6 Font - Names = " Verdana " Font - Size = " 0.8em " ForeColor = " #284E98 " /> 7 < LayoutTemplate > 8 < table border = " 0 " cellpadding = " 4 " cellspacing = " 0 " style = " border-collapse: collapse " > 9 < tr > 10 < td style = " width: 292px " > 11 < table border = " 0 " cellpadding = " 0 " > 12 < tr > 13 < td align = " center " colspan = " 2 " style = " font-weight: bold; font-size: 0.9em; color: white; 14 background - color: #507cd1 " > 15 登录 td>16 tr>17 <tr>18 <td align="left" style="width: 84px; height: 31px;">19 <asp:Label ID="UserNameLabel" runat="server" AssociatedControlID="UserName">用户名: asp:Label> td>20 <td style="height: 31px; width: 215px;">21 <asp:TextBox ID="UserName" runat="server" Font-Size="0.8em" Width="113px"> asp:TextBox>22 <asp:RequiredFieldValidator ID="UserNameRequired" runat="server" ControlToValidate="UserName"23 ErrorMessage="必须填写“用户名”。" ToolTip="必须填写“用户名”。" ValidationGroup="Login1">* asp:RequiredFieldValidator>24 td>25 tr>26 <tr>27 <td align="left" style="width: 84px">28 <asp:Label ID="PasswordLabel" runat="server" AssociatedControlID="Password">密码: asp:Label> td>29 <td style="width: 215px">30 <asp:TextBox ID="Password" runat="server" Font-Size="0.8em" TextMode="Password"> asp:TextBox>31 <asp:RequiredFieldValidator ID="PasswordRequired" runat="server" ControlToValidate="Password"32 ErrorMessage="必须填写“密码”。" ToolTip="必须填写“密码”。" ValidationGroup="Login1">* asp:RequiredFieldValidator>33 td>34 tr>35 <tr>36 <td style="width: 84px; height: 4px;" align="left">37 验证码: td>38 <td valign="middle" style="height: 31px; width: 215px;" align="left">39 <asp:TextBox ID="TextBox1" runat="server" Font-Size="0.8em" TextMode="Password"> asp:TextBox> 40 td>41 tr>42 <tr>43 <td align="left" colspan="2" style="color: red">44 <asp:CheckBox ID="RememberMe" runat="server" Text="下次记住我。" /> td>45 tr>46 <tr>47 <td align="right" colspan="2">48 <asp:Button ID="LoginButton" runat="server" BackColor="White" BorderColor="#507CD1"49 BorderStyle="Solid" BorderWidth="1px" CommandName="Login" Font-Names="Verdana"50 Font-Size="0.8em" ForeColor="#284E98" Text="登录" ValidationGroup="Login1" />51 td>52 tr>53 table>54 td>55 tr>56 table>57 LayoutTemplate>58 59 asp:Login>60 3.这里因为使用的是默认 *.asah处理文件类型,在machine.config文件中已经有此类型的默认注册,
1 < httpHandlers > 2 < add verb = " * " path = " *.asah " type = " System.Web.UI.SimpleHandlerFactory " /> 3 httpHandlers> 4 注意:
1.再注册一下也不会出错,会覆盖machine.config文件配置
2.如果在同一个配置文件中注册多次,默认后者也会覆盖前者.
3.如果其它格式(系统默认没有注册)的,务必要在Web.config文件中注册一下.
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