主题：连接SQsever登录问题(测试）

你确定按钮当然要出错，应为你屏蔽了这行代码：

Dim UserName As String = e.Form.Controls("UserName").Value
Dim cmd As New SQLCommand
Dim dt As DataTable
Dim dr As DataRow
'cmd.Connection Name = "test2"   外部数据源
If UserName = ""  Then
    Messagebox.show("请选择用户!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
    Return
End If

Dim UserName As String = e.Form.Controls("UserName").Value
Dim cmd As New SQLCommand
Dim dt As DataTable
Dim dr As DataRow
'cmd.Connection Name = "test2" 外部数据源
If UserName = ""  Then
    Messagebox.show("请选择用户!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
    Return
End If
cmd.CommandText = "Select * From {用户表} Where [用户名称] = '" & UserName & "'"
dt = cmd.ExecuteReader
If dt.DataRows.count = 0 Then
    Messagebox.show("不存在此用户!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
    Return
End If
dr = dt.DataRows(0)
If e.Form.Controls("PassWord").Value = dr("登录密码") Then
    _UserName = UserName
    _UserGroup = dr("分组名称")
    e.Form.Close

For Each t As Table In Tables
    t.Visible = True
    t.AllowEdit = True
    For Each c As Col In t.Cols
        c.Visible = True
        c.AllowEdit = True
    Next
Next

Tables("授权表").Visible = (_UserGroup = "管理人员A")

For Each dr1 As DataRow In DataTables("授权表").Select("分组名称 = '" & _UserGroup & "'" )
    If dr1.IsNull("列名称") Then
        Tables(dr1("表窗名称")).Visible = Not dr1("不可见")
        Tables(dr1("表窗名称")).AllowEdit = Not dr1("不可编辑")
    Else
        Tables(dr1("表窗名称")).Cols(dr1("列名称")).Visible = Not dr1("不可见")
        Tables(dr1("表窗名称")).Cols(dr1("列名称")).AllowEdit = Not dr1("不可编辑")
    End If
Next
   If  _usergroup <> "管理人员A" Then
      Tables("授权表").Visible = False
    Else
       Tables("授权表").Visible = True  
    End If

Else
    Messagebox.show("密码错误!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
End If

好好看看这里：

http://www.foxtable.com/help/topics/1485.htm

知道这么找出出错的代码，这样就能更快地找出原因。

此外要知道： 重定向之后，新数据库中的表是空的，你得重新增加用户来测试。