VB案例：学生成绩管理系统

VB案例：学生成绩管理系统
该系统针对成绩管理的实际情况，使用简单，功能实用，设置灵活。
利用该系统你能进行成绩表管理，包括建表、浏览、追加、修改、删除、查询、排序、统计分析等等功能，减少教师的重复劳动，提高工作效率。 该系统的版本V1.0，能够处理每学期科目不同的情况，可以随意设置科目名称，科目数最多可达15个，当然可以小于15个科目。
当您登录进入该系统，有两种不同的权限级别：管理员和浏览者。系统管理员的用户名是系统规定好的，为system，其权限包括系统维护、成绩表浏览、编辑、删除。而浏览者不能进行系统维护，也不能编辑和删除成绩表。
一、运行效果

















二、工程结构

三、工程目录结构


四、实现步骤（一）登录窗体frmLogin
1、界面设计




2、事件代码Dim Password As String, pp As String

Private Sub cmdExit_Click()
Unload Me
End
End Sub

Private Sub cmdLogin_Click()
Static i As Integer
If Txtpassword.Text = Password Then
Unload Me
Else
Me.Hide
i = i + 1
If i = 3 Then
MsgBox "您无权使用，请退出系统！", vbInformation, "登录失败！"
Unload Me
End
Else
MsgBox "密码错误，请重试！", vbInformation, "登录失败！"
Me.Show
Txtpassword.SetFocus
Txtpassword.SelStart = 0
Txtpassword.SelLength = Len(Txtpassword.Text)
End If
End If
End Sub

Private Sub Form_Activate()
Txtpassword.SetFocus
End Sub

Private Sub Form_Load()
pp = GetSetting(App.Title, "Login", "PWD", "")
Password = ""
For i = 1 To Len(pp)
Password = Password + Chr$(Asc(Mid$(pp, i)) - i)
Next i
End Sub

Private Sub Txtpassword_KeyPress(KeyAscii As Integer)
If KeyAscii = 13 Then
cmdLogin_Click
End If
End Sub3、运行效果




（二）主窗体MDIMain
1、界面设计




2、事件代码Private Sub MDIForm_Load()
ChDrive App.Path
ChDir App.Path
StatusBar1.Panels(2).Text = Format(Now, "yyyy年mm月dd日") & " " & WeekdayName(Weekday(Now))
End Sub

Private Sub MDIForm_Unload(Cancel As Integer)
If MsgBox("您要退出【学生成绩管理系统】吗？", vbYesNo + vbQuestion) = vbYes Then
End
Else
Cancel = True
End If
End Sub

Private Sub mnuAbout_Click()
frmAbout.Show
End Sub

Private Sub mnuAppend_Click()
frmAppend.Show
End Sub

Private Sub mnuBackup_Click()
frmBackup.Show
End Sub

Private Sub mnuBrowse_Click()
frmBrowse.Show
End Sub

Private Sub mnuClose_Click()
On Error Resume Next
mnuOpen.Enabled = True
mnuClose.Enabled = False
db.Close
mnuManipulate.Enabled = False
mnuManage.Enabled = True
MDIMain.StatusBar1.Panels(2).Text = ""
Unload MDIMain.ActiveForm
Toolbar1.Buttons("open").Enabled = True
Toolbar1.Buttons("close").Enabled = False
Toolbar1.Buttons("browse").Enabled = False
Toolbar1.Buttons("append").Enabled = False
Toolbar1.Buttons("edit").Enabled = False
Toolbar1.Buttons("delete").Enabled = False
Toolbar1.Buttons("find").Enabled = False
Toolbar1.Buttons("sort").Enabled = False
Toolbar1.Buttons("statistic").Enabled = False
StatusBar1.Panels(2).Text = Format(Now, "yyyy年mm月dd日") & " " & WeekdayName(Weekday(Now))
End Sub

Private Sub mnuContact_Click()
ShellExecute hWnd, "open", "mailto:maths007@163.com", 0, 0, 0
End Sub

Private Sub mnuContent_Click()
If Dir("c:\windows\hh.exe") <> "" Then
Shell "c:\windows\hh.exe " & App.Path & "\data\score.chm", vbNormalFocus
ElseIf Dir("c:\winnt\hh.exe") <> "" Then
Shell "c:\winnt\hh.exe " & App.Path & "\data\score.chm", vbNormalFocus
End If
End Sub

Private Sub mnuDelete_Click()
frmDelete.Show
End Sub

Private Sub mnuEdit_Click()
frmEdit.Show
End Sub

Private Sub mnuExit_Click()
Unload Me
End Sub

Private Sub mnuManage_Click()
frmManage.Show
End Sub

Private Sub mnuNew_Click()
frmNew.Show
End Sub

Private Sub mnuOpen_Click()
frmOpen.Show
End Sub

Private Sub mnuPassword_Click()
frmSetPWD.Show
End Sub

Private Sub mnuFind_Click()
frmFind.Show
End Sub

Private Sub mnuRestore_Click()
frmRestore.Show
End Sub

Private Sub mnuSort_Click()
frmSort.Show
End Sub

Private Sub mnuStatistic_Click()
frmStatistic.Show
End Sub

Private Sub Toolbar1_ButtonClick(ByVal Button As MSComctlLib.Button)
Select Case Button.Key
Case "new"
mnuNew_Click
Case "open"
mnuOpen_Click
Case "close"
mnuClose_Click
Case "browse"
mnuBrowse_Click
Case "append"
mnuAppend_Click
Case "edit"
mnuEdit_Click
Case "delete"
mnuDelete_Click
Case "find"
mnuFind_Click
Case "sort"
mnuSort_Click
Case "statistic"
mnuStatistic_Click
Case "help"
mnuContent_Click
End Select
End Sub3、运行结果




（三）关于窗体frmAbout
1、界面设计




2、事件代码Option Explicit

Private Sub Form_Load()
Me.Left = (MDIMain.ScaleWidth - Me.Width) / 2
Me.Top = (MDIMain.ScaleHeight - Me.Height) / 2
End Sub

Private Sub Timer1_Timer()
Unload Me
End Sub