图3.12用户登录界面
后台主要代码:
If TextBox1.Text = "" Then
MsgBox("用户名不能为空!", vbOKOnly + vbInformation, "友情提示")
Exit Sub
End If
If TextBox2.Text = "" Then
MsgBox("密码不能为空!", vbOKOnly + vbInformation, "友情提示")
Exit Sub
End If
Dim myconnection As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=客户信息管理系统数据库.mdb")
Dim mycommand1 As New OleDb.OleDbCommand("select * from 用户信息 where 用户名称='" & Trim(TextBox1.Text) & "' and 用户密码='" & Trim(TextBox2.Text) & "'", myconnection)
Dim mycommand2 As New OleDb.OleDbCommand("select * from 用户信息 where 用户名称='" & Trim(TextBox1.Text) & "' and 用户密码='" & Trim(TextBox2.Text) & "' and 权限等级='高级权限'", myconnection)
Dim mydatareader1 As OleDb.OleDbDataReader
Dim mydatareader2 As OleDb.OleDbDataReader
myconnection.Open()
mydatareader1 = mycommand1.ExecuteReader
mydatareader2 = mycommand2.ExecuteReader
If mydatareader1.Read = False Then
MsgBox("用户名不存在或者密码错误" + vbCrLf + " 请重新输入", 0 + 48, "友情提示")
TextBox2.Text = ""
TextBox2.Focus()
ElseIf mydatareader2.Read = True Then
Me.Close()
主界面.Show()