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VB图书管理系统源代码 第3页

更新时间:2009-7-10:  来源:毕业论文
VB图书管理系统源代码 第3页
Handles btnUpdate.Click
        '将在窗体中对数据的更改保存到数据库中
        Try
            Me.UpdateDataSet()
        Catch eUpdate As System.Exception
            System.Windows.Forms.MessageBox.Show(eUpdate.Message)
        End Try
        Me.objLib读者信息_PositionChanged()
    End Sub
    Public Sub UpdateDataSet()
        Dim objDataSetChanges As 图书馆管理.Lib读者信息 = _
        New 图书馆管理.Lib读者信息
        '创建一个新数据集来保存对主数据集所做的更改
        Me.BindingContext(objLib读者信息, "读者信息").EndCurrentEdit()
        '停止当前的任何编辑
        objDataSetChanges = CType(objLib读者信息.GetChanges, 图书馆管理.Lib读者信息)
        If (Not (objDataSetChanges) Is Nothing) Then
            Try
                Me.UpdateDataSource(objDataSetChanges)
                '调用UpdateDataSource函数将更改合并到数据集中
                objLib读者信息.Merge(objDataSetChanges)
                objLib读者信息.AcceptChanges()
            Catch eUpdate As System.Exception
                Throw eUpdate
            End Try
        End If
    End Sub
    Public Sub UpdateDataSource(ByVal ChangedRows As 图书馆管理.Lib读者信息)
        '打开数据连接,使用OleDbDataAdapter的Update方法更新数据库
        Try
            If (Not (ChangedRows) Is Nothing) Then
                Me.OleDbConnection1.Open()
                Me.OleDbDataAdapter1.Update(ChangedRows)
            End If
        Catch updateException As System.Exception
            Throw updateException
        Finally
            Me.OleDbConnection1.Close()
        End Try
    End Sub
    Private Sub btnNavFirst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNavFirst.Click
        Me.BindingContext(objLib读者信息, "读者信息").Position = 0
        Me.objLib读者信息_PositionChanged()
    End Sub
    Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
        Me.BindingContext(objLib读者信息, "读者信息").CancelCurrentEdit()
        Me.objLib读者信息_PositionChanged()
    End Sub
    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        If (Me.BindingContext(objLib读者信息, "读者信息").Count > 0) Then
            Me.BindingContext(objLib读者信息, "读者信息").RemoveAt _
            (Me.BindingContext(objLib读者信息, "读者信息").Position)
        End If
        Me.objLib读者信息_PositionChanged()
    End Sub
    Private Sub btnLast_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLast.Click
        Me.BindingContext(objLib读者信息, "读者信息").Position = _
        (Me.BindingContext(objLib读者信息, "读者信息").Count - 1)
        Me.objLib读者信息_PositionChanged()
    End Sub
    Private Sub btnNavPrev_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNavPrev.Click
        Me.BindingContext(objLib读者信息, "读者信息").Position = _
        (Me.BindingContext(objLib读者信息, "读者信息").Position - 1)
        Me.objLib读者信息_PositionChanged()
    End Sub
    Private Sub btnNavNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNavNext.Click
        Me.BindingContext(objLib读者信息, "读者信息").Position = _
        (Me.BindingContext(objLib读者信息, "读者信息").Position + 1)
        Me.objLib读者信息_PositionChanged()
    End Sub
    Private Sub btnCancelAll_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancelAll.Click
        Me.objLib读者信息.RejectChanges()
    End Sub
End Class
**鉴于“读者信息”,“管理者信息”,“出版社信息”,“书籍信息”,“借阅信息”模块除连接数据源不同外,设计思路步骤均相同,此处省略“管理者信息”,“出版社信息”,“书籍信息”,“借阅信息”四个模块的代码。
附:综合查询窗体设计代码如下:
Public Class 综合查询
    Inherits System.Windows.Forms.Form
#Region " Windows 窗体设计器生成的代码 "
‘此处省略窗体设计代码
#End Region
    Sub QueryData(ByVal SqlString As String, ByVal OrderString As String)
        QueryString = SqlString
        If OrderString <> "" Then
            QueryString = SqlString + " ORDER BY " + OrderString
        End If
    End Sub
    Public Sub LoadDataSet()
        Dim objDataSetTemp As 图书馆管理.Lib综合查询
        objDataSetTemp = New 图书馆管理.Lib综合查询
        Try
            Me.FillDataSet(objDataSetTemp)
        Catch eFillDataSet As System.Exception
            Throw eFillDataSet
        End Try
        Try
            objLib综合查询.Clear()
            objLib综合查询.Merge(objDataSetTemp)
        Catch eLoadMerge As System.Exception
            Throw eLoadMerge
        End Try
    End Sub
    Public Sub FillDataSet(ByVal dataSet As 图书馆管理.Lib综合查询)
        dataSet.EnforceConstraints = False
        Try
            If Me.OleDbConnection1.State <> ConnectionState.Closed Then
                Me.OleDbConnection1.Close()
            End If
            Me.OleDbConnection1.Open()
            Me.OleDbDataAdapter1.Fill(dataSet)
            Me.OleDbDataAdapter2.Fill(dataSet)
            Me.OleDbDataAdapter3.Fill(dataSet)
            Me.OleDbDataAdapter4.Fill(dataSet)
            Me.OleDbDataAdapter5.Fill(dataSet)
        Catch fillException As System.Exception
            Throw fillException
        Finally
            dataSet.EnforceConstraints = True
            Me.OleDbConnection1.Close()
        End Try
    End Sub
    Dim DataType(100) As String
    '该数组用来存储字段的数据类型

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