HTML代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>登陆系统</title> </head> <style type="text/css"> body { text-align:center; } table, td, tr { text-align: center;this.lblError.Text = "添加失败！"; } table { border: 1px solid #000000; } </style> <body> <form id="form1" runat="server"> <div> <table> <tr> <td colspan="2"> 登陆系统 </td> </tr> <tr> <td> 用户： </td> <td> <asp:TextBox ID="txtUserName" runat="server"></asp:TextBox><asp:Label ID="lblUserName" runat="server" ForeColor="Red" Text="*" Visible="false" ></asp:Label> </td> </tr> <tr> <td> 密码： </td> <td> <asp:TextBox ID="txtPassWord" runat="server" TextMode="Password"></asp:TextBox><asp:Label ID="lblPassWord" runat="server" ForeColor="Red" Visible="false" Text="*" ></asp:Label> </td> </tr> <tr> <td colspan="2"> <asp:Button ID="btnAddUser" runat="server" Text="注册" OnClick="btnAddUser_Click" /> <asp:Button ID="btnLogin" runat="server" Text="登陆" /> </td> </tr> <tr> <td colspan="2"> <asp:Label ID="lblError" runat="server" Text="" ForeColor="Red" Visible="false"></asp:Label></td> </tr> </table> </div> </form> </body> </html>
后台C#代码：
public partial class WebForm1 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void btnAddUser_Click(object sender, EventArgs e) { bool flag = true; if (string.IsNullOrEmpty(this.txtUserName.Text.Trim())) { this.lblUserName.Visible = true; flag = false; } if (string.IsNullOrEmpty(this.txtPassWord.Text.Trim())) { this.lblPassWord.Visible = true; flag = false; } if (flag) { if (DBHelper.IsExistUser(this.txtUserName.Text.Trim())) { if (DBHelper.Add(this.txtUserName.Text.Trim(), this.txtPassWord.Text.Trim())) { this.lblError.Visible = true; this.lblError.Text = "添加成功！"; } else { this.lblError.Text = "添加失败！"; this.lblError.Visible = true; } } else { this.lblError.Text = "添加失败，已存在的用户！"; this.lblError.Visible = true; } } } }
数据库的结构很简单，就不提供下载了看下图自己创建就可以了。我用的是access数据库，用其他的数据库如sqlserver、oracle修改下连接串就可以了。具体可以百度一下至于sql语句基本上都是大同小异，只有个别语法不同。
