学生管理系统优化

'txtUserName是输入用户名的文本框'
Private Sub txtUserName_Change()    'Len(text)：得到字符串的长度。不论中英文字符，均按1计数。'
    If Len(txtUserName.Text) > 15 Then  '限制输入长度为15，一旦超过就只显示前15'
        txtUserName.Text = Left(txtUserName.Text, 15)
        txtUserName.SelStart = 15   '作用是选中排名前15的字符'
    End If
End Sub

'判断电话号码是否小于7位数'
If Len(txtTel.Text) < 7 Then
    MsgBox "电话号码不能小于7位！", vbOKOnly + vbExclamation, "警告"
    Exit Sub
    txtTel.SetFocus
End If

'设置用户名输入的格式'
Private Sub txtUserName_KeyPress(KeyAscii As Integer)
  Select Case KeyAscii
          Case 48 To 57, 65 To 90, 97 To 122
                Exit Sub
          Case 8
                Exit Sub
          Case Else
                MsgBox "请输入数字或英文"
    End Select
    KeyAscii = 0
End Sub

Private Sub txtDirector_KeyPress(KeyAscii As Integer)
   If KeyAscii < 0 Or KeyAscii = 8 Or KeyAscii = 13 Then
   ElseIf Not Chr(KeyAscii) Like "[a-zA-Z]" Then
   KeyAscii = 0
   End If
End Sub

'文本框只能输入数字，且能退格'
Private Sub txtClassno_KeyPress(KeyAscii As Integer)
 Select Case KeyAscii
          Case 48 To 57
                Exit Sub
          Case 8
                Exit Sub
    End Select
    KeyAscii = 0
End Sub

Private Sub txtComment_KeyPress(KeyAscii As Integer)
Dim cTemp As String
   cTemp = "`~!@#$%^&*()-=_+[]{};:'\|<>/?.‘“”’、，。——+（）《》？,~·……￥！：；【】" & """ '禁止输入特殊的字符"
If InStr(1, cTemp, Chr(KeyAscii)) <> 0 Then KeyAscii = 0
End Sub

Private Sub cmdOK_Click()       '点击确定登录'
  PassWord = Trim(txtPassword.Text) '把登陆时输入的密码赋给公有变量PassWord'
End Sub

If PassWord <> Text1(0).Text Then
  MsgBox "原密码输入不正确", vbOKOnly + vbExclamation, "修改密码"
End If

Private Sub firstCommand_Click()  '第一条记录按钮'
      mrc.MoveFirst    '移动到数据集的第一条记录
      Call viewData     '调用显示数据的函数
     If mrc.RecordCount = 1 Then
        MsgBox "只剩下这一条记录！", vbOKCancel + vbExclamation, "警告"
     End If
End Sub

Private Sub lastCommand_Click()    '最后一条记录按钮'
      mrc.MoveLast  '移动到数据集的最后一条记录
      Call viewData      '调用显示数据的函数
      If mrc.RecordCount = 1 Then
        MsgBox "只剩下这一条记录！", vbOKCancel + vbExclamation, "警告"
      End If
End Sub

Private Sub nextCommand_Click()   '下一条记录按钮'
     If mrc.RecordCount = 1 Then
        MsgBox "只剩下这一条记录！", vbOKCancel + vbExclamation, "警告"
     Else
      mrc.MoveNext      '数据集向后移动'
      If mrc.EOF Then   '判断是否到末位置'
        MsgBox "这已经是最后一条记录了!", vbOKOnly + vbExclamation, "警告"
          mrc.MovePrevious  '将记录指针移至上一条'
      End If
    End If
    Call viewData
End Sub

Private Sub previousCommand_Click()     '上一条记录按钮'
    If mrc.RecordCount = 1 Then
        MsgBox "只剩下这一条记录！", vbOKCancel + vbExclamation, "警告"
    Else
        mrc.MovePrievious '将记录指针移至上一条'
        If mrc.BOF Then   '如果记录指针到顶了'
            mrc.MoveLast  '将记录指针移至下一条'
        End If
    End If
    Call viewData
End Sub

Private Sub deleteCommand_Click() '删除记录按钮'
On Error GoTo P_Err   '遇到错误跳转到P_Err错误处理程序'
…………………………………………
p_EXIT:
    Exit Sub      
P_Err:          '清空记录集并提示'
    txtSID.Text = ""
    txtName.Text = ""
    comboSex.Text = ""
    txtBorndate.Text = ""
    comboClassNo.Text = ""
    txtTel.Text = ""
    txtRudate.Text = ""
    txtAddress.Text = ""
    txtComment.Text = ""
    MsgBox "最后一条信息已删除，即将退出!", vbOKOnly + vbCritical, "警告"
    Unload Me
    GoTo p_EXIT
End Sub

Private Sub Form_Load()
    Dim txtSQL As String
    Dim MsgText As String
    txtSQL = "select * from student_Info"
    Set mrc = ExecuteSQL(txtSQL, MsgText)   '执行查询操作 '得到student表，并显示出来
    If mrc.RecordCount = 0 Then   '当前记录集为空'
        MsgBox "暂无学籍信息，请先录入", vbOKCancel + vbExclamation, "警告"
        Frame2.Enabled = False  'Frame里的按钮都不可点击'
        Frame3.Enabled = False
    Else
         'select得到的临时表，游标指向尾记录，在Access中指向第一条'
        mrc.MoveFirst   '移动到第一条记录'
        Call viewData   '显示数据'
        myBookmark = mrc.Bookmark '做标记'
        mcclean = True  '给标志赋初值'
    End If
End Sub