添加用户.frm

初学vb,做的第一个系统.一个星期内看vb并做完这个系统的.

VERSION 5.00
Object = "{67397AA1-7FB1-11D0-B148-00A0C922E820}#6.0#0"; "MSADODC.OCX"
Begin VB.Form newuser 
   BorderStyle     =   1  'Fixed Single
   Caption         =   "添加用户"
   ClientHeight    =   2340
   ClientLeft      =   4740
   ClientTop       =   4485
   ClientWidth     =   4245
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   ScaleHeight     =   2340
   ScaleWidth      =   4245
   Begin VB.CommandButton Command2 
      Caption         =   "返回"
      Height          =   495
      Left            =   1560
      TabIndex        =   5
      Top             =   1560
      Width           =   1095
   End
   Begin VB.TextBox Text2 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   12
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   375
      IMEMode         =   3  'DISABLE
      Left            =   1800
      PasswordChar    =   "*"
      TabIndex        =   1
      Top             =   960
      Width           =   1695
   End
   Begin VB.TextBox Text1 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   12
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   375
      Left            =   1800
      TabIndex        =   0
      Top             =   360
      Width           =   1695
   End
   Begin MSAdodcLib.Adodc Adodc1 
      Height          =   330
      Left            =   240
      Top             =   2040
      Visible         =   0   'False
      Width           =   1200
      _ExtentX        =   2117
      _ExtentY        =   582
      ConnectMode     =   0
      CursorLocation  =   3
      IsolationLevel  =   -1
      ConnectionTimeout=   15
      CommandTimeout  =   30
      CursorType      =   3
      LockType        =   3
      CommandType     =   8
      CursorOptions   =   0
      CacheSize       =   50
      MaxRecords      =   0
      BOFAction       =   0
      EOFAction       =   0
      ConnectStringType=   1
      Appearance      =   1
      BackColor       =   -2147483643
      ForeColor       =   -2147483640
      Orientation     =   0
      Enabled         =   -1
      Connect         =   "Provider=MSDASQL.1;Persist Security Info=False;User ID=sa;Data Source=stu_manage"
      OLEDBString     =   "Provider=MSDASQL.1;Persist Security Info=False;User ID=sa;Data Source=stu_manage"
      OLEDBFile       =   ""
      DataSourceName  =   ""
      OtherAttributes =   ""
      UserName        =   ""
      Password        =   ""
      RecordSource    =   ""
      Caption         =   "Adodc1"
      BeginProperty Font {0BE35203-8F91-11CE-9DE3-00AA004BB851} 
         Name            =   "宋体"
         Size            =   9
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      _Version        =   393216
   End
   Begin VB.CommandButton Command1 
      Caption         =   "添加"
      Height          =   495
      Left            =   2880
      TabIndex        =   2
      Top             =   1560
      Width           =   1095
   End
   Begin VB.Label Label2 
      Caption         =   "密  码"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   12
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   375
      Left            =   720
      TabIndex        =   4
      Top             =   960
      Width           =   855
   End
   Begin VB.Label Label1 
      Caption         =   "用户名"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   12
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   375
      Left            =   720
      TabIndex        =   3
      Top             =   360
      Width           =   735
   End
End
Attribute VB_Name = "newuser"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False

'添加按钮
Private Sub Command1_Click()
    Dim mm As String
    Dim nn As String

    Dim rs As New ADODB.Recordset
    Dim adoconn As New ADODB.Connection 'Connection 对象代表了打开与数据源的连接。

    adoconn.ConnectionString = Adodc1.ConnectionString 'Adodc1为窗体中的ADO控件，并已成功连接数据库
    adoconn.Open
    Set rs = New ADODB.Recordset
    rs.CursorLocation = adUseClient
    rs.CursorType = adOpenKeyset
    rs.LockType = adLockOptimistic
    
    mm = Text1.Text
    nn = Text2.Text
    
    '检查输入信息是否有空值或长度太大
    rs.Open "select * from admin", adoconn
    If Len(mm) = 0 Then
        rs.Close
        MsgBox "用户名不能为空！"
        Text1.SetFocus
        Exit Sub
    ElseIf Len(nn) <= 5 Then
        rs.Close
        MsgBox "密码长度不能少于6位，请重新设置！"
        Text2.Text = ""
        Text2.SetFocus
        Exit Sub
    ElseIf Len(mm) >= 13 Then
        rs.Close
        MsgBox "用户名最多只允许12位，请重新设置！"
        Text1.Text = ""
        Text1.SetFocus
        Exit Sub
    ElseIf Len(nn) >= 17 Then
        rs.Close
        MsgBox "密码至多只允许16位，请重新设置！"
        Text2.Text = ""
        Text2.SetFocus
        Exit Sub
    End If
    
    '数据库中没有用户信息时
    If rs.RecordCount = 0 Then
        rs.AddNew
        rs.Fields("id") = mm
        rs.Fields("pwd") = nn
        rs.Update
        rs.Close
        Text1.Text = ""
        Text2.Text = ""
        MsgBox "添加用户成功"
        Text1.SetFocus

    Else
        '数据库中至少存在一个用户信息，判断新输入的用户是否已经存在
        rs.MoveFirst
        For i = 0 To rs.RecordCount - 1
            If mm = rs.Fields("id") Then
                MsgBox "该用户已经存在！"
                Text1.Text = ""
                Text2.Text = ""
                Text1.SetFocus
                Exit Sub
            End If
            rs.MoveNext
        Next i
        '新输入的用户名在数据库中找不到，且输入不为空值，则添加进数据库
        rs.AddNew
        rs.Fields("id") = mm
        rs.Fields("pwd") = nn
        rs.Update
        rs.Close
        
        MsgBox "添加用户成功"
        Text1.Text = ""
        Text2.Text = ""
        Text1.SetFocus
    End If
    

End Sub
'返回“用户管理”页面
Private Sub Command2_Click()
    Unload Me
    manage.Show
End Sub