登录模块的后台代码有问题!请高手帮忙!不胜感激---
Imports System.IO
Imports System.Data
Imports System.Data.SqlClient
Imports System.Resources
Public Class login
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'判断是否为空
If ComboBox1.Text = "" Or TextBox1.Text = "" Then
MessageBox.Show("用户名或密码不能为空", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
Exit Sub
End If
'数据库连接
Dim mycon As SqlConnection '声明连接对象
Dim Connectionstring As String = "server=localhost;database=mysql;uid=sa;pwd=123;" '连接字符串
mycon = New SqlConnection(Connectionstring) '创建连接
If mycon.State = ConnectionState.Closed Then
mycon.Open() '打开数据库
End If
Dim sqlstr As String = "select * from administrator where name = combobox1.text & password = textbox1.text"
Dim mycom As New SqlCommand(sqlstr, mycon)
Dim i As Integer = 0
If mycom.ExecuteScalar <> 1 Then
i = i + 1
If i > 3 Then
MsgBox("你已经3次输入错误密码!请下次再登录吧!")
Me.Button1.Enabled = False
Else
MessageBox.Show("密码错误!请重新输入!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
End If
TextBox1.Text = ""
ComboBox1.SelectedIndex = 0
Exit Sub
Else
'Me.管理员维护 toolstuipmenultem.enabled = True
'Me.添加管理员 toolstuipmenultem.enabled = True
'Me.增加读者信息 toolstuipmenultem.enabled = True
'Me.读者信息维护 toolstuipmenultem.enabled = True
'me.查看借阅历史 toolstuipmenultem.enabled = True
'me.书籍借阅管理 toolstuipmenultem.enabled = True
'Me.书籍信息查询 toolstuipmenultem.enabled = True
'me.书籍信息维护 toolstuipmenultem.enabled = True
'Me.读者信息查询 toolstuipmenultem.enabled = True
'Me.新增书籍管理 toolstuipmenultem.enabled = True
MessageBox.Show("恭喜你登陆成功!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Information)
End If
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Application.Exit()
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim str1, str2 As String
str1 = vbCrLf & "关于用户" & vbCrLf
str2 = "系统默认用户名为:admin " & vbCrLf & "密码为:admin" & vbCrLf & "登录后请及时修改"
MsgBox(str1 & str2, MsgBoxStyle.OkOnly Or MsgBoxStyle.Information, "帮助信息")
End Sub
End Class