www.pudn.com > cjg2.rar > frmClass.frm
VERSION 5.00
Begin VB.Form Class
BorderStyle = 1 'Fixed Single
Caption = "班级信息管理"
ClientHeight = 1980
ClientLeft = 45
ClientTop = 330
ClientWidth = 4695
LinkTopic = "Form1"
MaxButton = 0 'False
MDIChild = -1 'True
MinButton = 0 'False
ScaleHeight = 1980
ScaleWidth = 4695
Begin VB.TextBox txtNum
Height = 270
IMEMode = 2 'OFF
Left = 1740
MaxLength = 8
TabIndex = 1
Top = 608
Width = 2010
End
Begin VB.CommandButton cmdSave
Caption = "保存"
Height = 300
Left = 2355
TabIndex = 4
Top = 1073
Width = 735
End
Begin VB.CommandButton cmdExit
Cancel = -1 'True
Caption = "退出"
Height = 315
Left = 3120
TabIndex = 5
Top = 1066
Width = 735
End
Begin VB.CommandButton cmdDelete
Caption = "删除"
Height = 300
Left = 1605
TabIndex = 3
Top = 1073
Width = 735
End
Begin VB.CommandButton cmdAdd
Caption = "添加"
Height = 300
Left = 840
TabIndex = 2
Top = 1073
Width = 735
End
Begin VB.TextBox txtName
Height = 270
IMEMode = 1 'ON
Left = 1740
MaxLength = 20
TabIndex = 0
Top = 248
Width = 2010
End
Begin VB.PictureBox picNavigation
AutoSize = -1 'True
BorderStyle = 0 'None
Height = 360
Left = 1005
ScaleHeight = 360
ScaleWidth = 2685
TabIndex = 10
Top = 1373
Width = 2685
Begin VB.CommandButton cmdMove
Height = 300
Index = 1
Left = 360
Picture = "frmClass.frx":0000
Style = 1 'Graphical
TabIndex = 7
Top = 15
Width = 345
End
Begin VB.CommandButton cmdMove
Height = 300
Index = 0
Left = 30
Picture = "frmClass.frx":0045
Style = 1 'Graphical
TabIndex = 6
Top = 15
Width = 345
End
Begin VB.CommandButton cmdMove
Height = 300
Index = 3
Left = 2280
Picture = "frmClass.frx":0092
Style = 1 'Graphical
TabIndex = 9
Top = 15
Width = 345
End
Begin VB.CommandButton cmdMove
Height = 300
Index = 2
Left = 1950
Picture = "frmClass.frx":00E1
Style = 1 'Graphical
TabIndex = 8
Top = 15
Width = 345
End
Begin VB.TextBox txtNews
Height = 300
Left = 690
Locked = -1 'True
TabIndex = 11
TabStop = 0 'False
Top = 15
Width = 1275
End
End
Begin VB.Label Label1
AutoSize = -1 'True
Caption = "班级编号"
Height = 180
Left = 930
TabIndex = 13
Top = 668
Width = 720
End
Begin VB.Label Label2
AutoSize = -1 'True
Caption = "班级名称"
Height = 180
Left = 930
TabIndex = 12
Top = 278
Width = 720
End
End
Attribute VB_Name = "Class"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Dim isAdding As Boolean '定义操作状态标志
Dim objGrade As Recordset '用于保存班级信息记录
Dim objCn As Connection '用于建立数据库联接
Private Sub cmdExit_Click()
Unload Me '关闭班级信息管理窗体
End Sub
Private Sub Form_Load()
'建立数据库联接
Set objCn = New Connection '实例化联接对象
With objCn '建立数据库联接
.Provider = "SQLOLEDB"
.ConnectionString = "User ID=sa;PWD=123;Data Source=(local);" & _
"Initial Catalog=自测考试"
.Open
End With
'获取班级信息记录
Set objGrade = New Recordset '实例化objGrade对象
With objGrade
Set .ActiveConnection = objCn '设置数据库联接
.CursorLocation = adUseClient '指定使用客户端游标
.CursorType = adOpenStatic '指定使用静态游标
.LockType = adLockOptimistic
.Open "SELECT * FROM 班级信息" '获取班级信息记录
End With
'触发按钮单击事件，显示第一个记录
cmdMove(0).Value = True
End Sub
Private Sub cmdMove_Click(Index As Integer)
With objGrade
Select Case Index '切换当前记录
Case 0 '使第一个记录成为当前记录
If .RecordCount > 0 And Not .BOF Then .MoveFirst
Case 1 '使上一个记录成为当前记录
If .RecordCount > 0 And Not .BOF Then
.MovePrevious
If .BOF Then .MoveFirst
End If
Case 2 '使下一个记录成为当前记录
If .RecordCount > 0 And Not .EOF Then
.MoveNext
If .EOF Then .MoveLast
End If
Case 3 '使最后一个记录成为当前记录
If .RecordCount > 0 And Not .EOF Then .MoveLast
End Select
If .RecordCount < 1 Then
txtNews = "记录：无" '显示无记录提示
txtNum = ""
txtName = ""
Else
'显示当前记录数据
ShowData
End If
End With
If isAdding Then isAdding = False
End Sub
Private Sub cmdAdd_Click()
txtNews = "添加新记录"
txtNum = ""
txtName = ""
isAdding = True
End Sub
Private Sub cmdDelete_Click()
'根据是否处于添加记录状态执行不同的操作
If isAdding Then
'退出添加记录状态，显示当前记录
isAdding = False
If objGrade.RecordCount < 1 Then
txtNews = "记录：无" '显示无记录提示
txtNum = ""
txtName = ""
Else
'显示当前记录数据
ShowData
End If
Else
If objGrade.RecordCount > 0 Then
'检查在课程编号是否被《学生信息》表引用
'如果被使用，则不执行删除操作
Dim objTemp As New Recordset
With objTemp
Set .ActiveConnection = objCn '设置数据库联接
.CursorLocation = adUseClient '指定使用客户端游标
.CursorType = adOpenStatic '指定使用静态游标
'检查课程编号是否被《学生信息》表引用
.Open "SELECT TOP 1 * FROM 学生信息 WHERE 班级='" & Trim(txtNum) & "'"
If .RecordCount > 0 Then
MsgBox "编号被《学生信息》表使用，不能删除当前记录！", vbInformation, "班级信息管理"
.Close '关闭对象
Set objTemp = Nothing '释放对象
Exit Sub
End If
.Close '关闭对象
End With
Set objTemp = Nothing '释放对象
'可以删除，请求确认执行删除操作
If MsgBox("是否删除当前记录？", vbYesNo + vbQuestion, "班级信息管理") = vbYes Then
'执行删除当前记录操作
objGrade.Delete
'显示下一记录数据
cmdMove(2).Value = True
Else
'显示当前记录数据
ShowData
End If
End If
End If
End Sub
Private Sub cmdSave_Click()
'在当前表中无数据和不是添加记录时，不执行保存操作
If Not isAdding And objGrade.RecordCount < 1 Then Exit Sub
'获得当前记录数据
Dim strNum$, strName$
strNum = Trim(txtNum)
strName = Trim(txtName)
'检验是否输入班级名称
If strName = "" Then
MsgBox "班级名称不能为空！", vbCritical, "班级信息管理"
txtName.SetFocus
txtName = ""
Exit Sub
End If
'检验是否输入班级编号
If Len(strNum) <> 8 Then
MsgBox "班级编号必须为8位数字！", vbCritical, "班级信息管理"
txtNum.SetFocus
txtNum = ""
Exit Sub
End If
'在进一步保存添加的新记录或修改的当前记录之前，检查班级编号是否重复
Dim objCopy As New Recordset
Set objCopy = objGrade.Clone
If objGrade.RecordCount > 0 And Not isAdding Then
objCopy.MoveFirst
objCopy.Find "编号='" & strNum & "'"
If Not objCopy.EOF And objCopy.AbsolutePosition <> objGrade.AbsolutePosition Then
MsgBox "班级编号：" & strNum & "已被使用，请使用其他编号！", _
vbCritical, "班级信息管理"
txtNum.SetFocus
txtNum.SelStart = 0
txtNum.SelLength = Len(txtNum)
Exit Sub '班级编号重复，直接退出
End If
End If
'班级编号不重复，执行下一步保存操作
With objGrade
If isAdding Then
.AddNew '添加新记录
Else
'保存被修改的当前记录
If .Fields("编号") <> strNum Then
If MsgBox("修改编号将影响《学生信息》表中的相关记录，是否继续？", _
vbYesNo + vbQuestion, "班级信息管理") = vbNo Then
'取消修改，还原当前记录
ShowData
Exit Sub
End If
End If
End If
'修改记录
.Fields("编号") = strNum
.Fields("名称") = strName
'执行更新操作
.Update
MsgBox "数据保存成功！", vbInformation, "班级信息管理"
isAdding = False
'显示当前记录编号和记录总数
txtNews = "记录：" & .AbsolutePosition & "/" & .RecordCount
End With
End Sub
Private Sub Form_Unload(Cancel As Integer)
objCn.Close '关闭数据联接
Set objCn = Nothing '释放数据库联接
Set objGrade = Nothing '释放记录集对象
End Sub
Private Sub txtName_KeyPress(KeyAscii As Integer)
'如果敲回车键，使下一控件获得焦点
If KeyAscii = vbKeyReturn Then SendKeys "{TAB}"
End Sub
'限制编号输入
Private Sub txtNum_KeyPress(KeyAscii As Integer)
'如果敲回车键，使保存按钮获得焦点
If KeyAscii = vbKeyReturn Then cmdSave.SetFocus
If Not (Chr(KeyAscii) Like "[0-9]" Or KeyAscii = vbKeyBack) Then
KeyAscii = 0 '输入不是数字或退格键，取消输入
End If
End Sub
'显示objGrade当前记录信息
Private Sub ShowData()
With objGrade
'显示当前记录数据
txtName = .Fields("名称")
txtNum = .Fields("编号")
'显示当前记录编号和记录总数
txtNews = "记录：" & .AbsolutePosition & "/" & .RecordCount
End With
End Sub