可视化程序设计(VB)之Data控件应用例子.doc

本应用程序设计一个窗体，如图1所示，窗体中包含的各控件及其属性设置如表1所列。图1 Data控件应用例子设计界面表1 控件及其属性设置控件名字属性属性值Data1CaptionData1 ConnectAccess DatabaseNameE:vbstudent.mdb DefaultCursorType0 默认游标 DefaultType2 使用 ODBC Exclusive0 False Options0 ReadOnly0 False RecordsetType1 Dynaset RecordSource学生表Combo1DataField性别 DataSourceData1Combo2DataField民族 DataSourceData1cmdAddCaption添加cmdDeleteCaption删除cmdFindCaption查找cmdUpdateCaption更新cmdCloseCaption关闭txtFields(0)DataField学号 DataSourceData1txtFields(1)DataField姓名 DataSourceData1txtFields(2)DataField班号 DataSourceData1lblLabels(0)AutoSize-1 True Caption学号:续表控件名字属性属性值lblLabels(1)AutoSize-1 True Caption姓名:lblLabels(2)AutoSize-1 True Caption性别:lblLabels(3)AutoSize-1 True Caption民族:lblLabels(4)AutoSize-1 True Caption班号:本例的执行界面如图2所示。在开始时，数据库表中数据为空，先单击“添加”按钮，然后输入或选择各字段的值，然后单击“更新”按钮，则输入了一个记录。图2 Data控件应用例子执行界面在本例窗体中设计如下事件过程：Private Sub cmdAdd_Click() Data1.Recordset.AddNew cmdDelete.Enabled = False cmdFind.Enabled = False cmdUpdate.Enabled = True txtFields(0).SetFocusEnd SubPrivate Sub cmdDelete_Click() If MsgBox(真的要删除当前记录吗, vbYesNo, 信息提示) = vbYes Then Data1.Recordset.Delete Data1.Recordset.MoveNext If Data1.Recordset.EOF Then Data1.Recordset.MoveFirst If Data1.Recordset.BOF Then cmdDelete.Enabled = False cmdFind.Enabled = False End If End If End IfEnd SubPrivate Sub cmdClose_Click() Unload MeEnd SubPrivate Sub cmdFind_Click() Dim str As String str = InputBox(输入查找表达式,如年龄=9, 查找) If str = Then Exit Sub Data1.Recordset.FindFirst str If Data1.Recordset.NoMatch Then MsgBox 指定的条件没有匹配的记录, , 信息提示 End IfEnd SubPrivate Sub cmdUpdate_Click() Data1.UpdateRecord Data1.Recordset.Bookmark = Data1.Recordset.LastModified cmdUpdate.Enabled = False cmdDelete.Enabled = True cmdFind.Enabled = TrueEnd SubPrivate Sub Data1_Error(DataErr As Integer, Response As Integer) MsgBox 数据错误事件命中错误： & Error$(DataErr) Response = 0 忽略错误End SubPrivate Sub Data1_Reposition() Screen.MousePointer = vbDefault On Error Resume Next Data1.Caption = 记录： & (Data1.Recordset.AbsolutePosition + 1)End SubPrivate Sub Form_Initialize() If Data1.Recordset.EOF And Data1.Recordset.BOF Then 检测记录集是否为空 cmdFind.Enabled =