设计首页和登录页面

本节的任务是设计一个登录页面：

如果用户名和密码错误，会显示2秒的错误提示：

如果用户名和密码正确，进入首页：

如果在首页点击退出，会回到登录页面。

HttpRequest事件代码：

Dim wb As New weui
'身份验证
Dim Verified As Boolean '用于标记用户是否通过了身份验证
Dim UserName As String = e.Cookies("username") '从cookie中获取用户名
Dim Password As String = e.Cookies("password") '从cookie中获取用户密码
If e.Path = "logon.htm" '如果是通过登录页面访问,从PostValues即可中提取用户名和密码
    If e.PostValues.ContainsKey("username") AndAlso e.PostValues.ContainsKey("password")  Then
        UserName = e.PostValues("username")
        Password = e.PostValues("password")
    End If
End If
If UserName = "张三" AndAlso Password = "888" Then  '实际使用的时候,请改为从数据库读取用户名和密码进行比较
    Verified  = True
ElseIf Username = "李四" AndAlso Password="999" Then
    Verified  = True
End If
If Verified AndAlso e.Path = "logon.htm"  Then '如果用户访问的是登录页,且身份验证成功
    wb.AppendCookie("username",UserName) '将用户名和密码写入cookie
    wb.AppendCookie("password",Password)
    wb.InsertHTML("<meta http-equiv='Refresh' content='0; url=/default.htm'>") '直接跳转到首页
    e.WriteString(wb.Build) '生成网页
    Return '必须的
ElseIf Verified = False AndAlso e.Path <> "logon.htm" Then '如果用户身份验证失败,且访问的不是登录页面
    wb.InsertHTML("<meta http-equiv='Refresh' content='0; url=/logon.htm'>") '那么直接跳转到登录页面
    e.WriteString(wb.Build) '生成网页
    Return '必须的
End If
'开始生成网页
Select Case e.path
    Case "logon.htm" '登录页面
        wb.AddPageTitle("","pageheader","销售系统","由湛江辉迅基于Foxtable开发")
        If e.PostValues.ContainsKey("username") AndAlso e.PostValues.ContainsKey("password")  Then '判断是否是验证失败后的重新登录
            wb.AddTopTips("","toptip1","用户名或密码错误!").msec = 2000 '如果用户通过登录按钮访问,则给用户一个2秒的提示.
        End If
        wb.AddForm("","form1","logon.htm")
        With wb.AddInputGroup("form1","ipg1")
            .AddInput("username","户名","text")
            .AddInput("password","密码","password")
        End With
        With wb.AddButtonGroup("form1","btg1",True)
            .Add("btn1", "登录", "submit")
        End With
    Case "exit.htm" '退出登录
        wb.DeleteCookie("username") '清除cookie中原来的用户名和密码
        wb.DeleteCookie("password")
        wb.InsertHTML("<meta http-equiv='Refresh' content='0; url=/logon.htm'>") '那么直接跳转到登录页面
    Case "", "default.htm" '首页
        wb.AddPageTitle("","pageheader","销售系统","由湛江辉迅基于Foxtable开发")
        With wb.AddGrid("","g1")
            .Add("c1","增加订单", "./images/button.png").Attribute = "onclick='javascript:alert(""你单击了我!"")'"
            .Add("c2","客户管理", "./images/cell.png", "http://www.foxtable.com")
            .Add("c3","销售统计", "./images/toast.png", "http://www.foxtable.com")
            .Add("c4","Dialog", "./images/dialog.png", "http://www.foxtable.com")
            .Add("c5","Progress", "./images/progress.png", "http://www.foxtable.com")
            .Add("c6","Msg", "./images/msg.png", "http://www.foxtable.com")
            .Add("c7","Article", "./images/article.png", "http://www.foxtable.com")
            .Add("c8","ActionSheet", "./images/actionSheet.png", "http://www.foxtable.com")
            .Add("c9","Icons", "./images/icons.png", "http://www.foxtable.com")
            .Add("c10","Panel", "./images/panel.png", "http://www.foxtable.com")
            .Add("c11","Tab", "./images/tab.png", "http://www.foxtable.com")
            .Add("c12","退出", "./images/exit.png", "exit.htm") '退出登录
        End With
End Select
e.WriteString(wb.Build) '生成网页

代码逻辑并不复杂，所有知识之前都已经讲述过，唯一没有接触过的是自动跳转网页的代码：

<meta http-equiv='refresh' content='2; url=/logon.htm'>

表示2秒后跳转到"/logon.htm"页面，如果你要立即跳转，将2改为0即可。