bookedit.vb

vb.net写的图书管理系统,功能完备,能正常使用,可用于二次开发.

        '
        'dtpPressDate
        '
        Me.dtpPressDate.Location = New System.Drawing.Point(168, 168)
        Me.dtpPressDate.Name = "dtpPressDate"
        Me.dtpPressDate.Size = New System.Drawing.Size(211, 21)
        Me.dtpPressDate.TabIndex = 26
        '
        'Label6
        '
        Me.Label6.AutoSize = True
        Me.Label6.Location = New System.Drawing.Point(24, 60)
        Me.Label6.Name = "Label6"
        Me.Label6.Size = New System.Drawing.Size(29, 17)
        Me.Label6.TabIndex = 24
        Me.Label6.Text = "作者"
        '
        'txtAuthorName
        '
        Me.txtAuthorName.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
        Me.txtAuthorName.Location = New System.Drawing.Point(168, 56)
        Me.txtAuthorName.Name = "txtAuthorName"
        Me.txtAuthorName.Size = New System.Drawing.Size(211, 21)
        Me.txtAuthorName.TabIndex = 25
        Me.txtAuthorName.Text = ""
        '
        'btnDelete
        '
        Me.btnDelete.Location = New System.Drawing.Point(168, 368)
        Me.btnDelete.Name = "btnDelete"
        Me.btnDelete.Size = New System.Drawing.Size(80, 25)
        Me.btnDelete.TabIndex = 27
        Me.btnDelete.Text = "删除"
        '
        'BookEdit
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(460, 405)
        Me.Controls.Add(Me.btnDelete)
        Me.Controls.Add(Me.GroupBox2)
        Me.Controls.Add(Me.GroupBox1)
        Me.Controls.Add(Me.btnCancel)
        Me.Controls.Add(Me.btnUpdate)
        Me.Name = "BookEdit"
        Me.Text = "书籍信息维护"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox2.ResumeLayout(False)
        Me.ResumeLayout(False)

    End Sub

#End Region
    '用于判断书籍类型是否改变
    Dim changeFlg As Boolean
    '用于判断书籍是否改变
    Dim changeBookFlg As Boolean

    '首先校验用户输入数据的合法性问题，然后更新到数据库
    Private Sub btnUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
        '如果用户输入数据不合法，则退出
        If Not checkData() Then
            Exit Sub
        End If
        '生成SQL语句
        Dim strSQL As String
        strSQL = "Update BookInfo set "
        strSQL &= "name ='" & txtBookName.Text.Trim & "',"
        strSQL &= "author ='" & txtAuthorName.Text.Trim & "',"
        strSQL &= "price = '" & txtBookPrice.Text.Trim & "',"
        strSQL &= "press = '" & txtPress.Text.Trim & "',"
        strSQL &= "pressdate ='" & dtpPressDate.Value.Date & "'"
        strSQL &= "where ISBN=" & cmbBookISBN.SelectedValue & ""
        '用于记录更新操作是否成功
        Dim ret As Boolean
        '更新数据库中数据
        ret = DBManager.executeNonQuery(strSQL)
        If ret Then
            '给出提示信息
            InfoMSG("书籍信息更新成功！")
        Else
            '给出错误信息
            ErrorMSG("书籍信息更新失败！")
        End If
    End Sub

    '退出窗体
    Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCancel.Click
        Me.Close()
    End Sub
    Private Sub cmbBookType_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbBookType.SelectedIndexChanged
        '用于记录结果集
        Dim mydt As DataSet
        Dim strSQL As String
        If changeFlg Then
            '生成SQL语句
            strSQL = "select  ISBN , NAME  from BookInfo where TYPE=" & cmbBookType.SelectedValue
            '执行SQL语句，得到结果集
            mydt = DBManager.executeSelectQuery(strSQL, "BookInfo")
            '填充书籍列表
            cmbBookISBN.DataSource = mydt.Tables("BookInfo")
            cmbBookISBN.DisplayMember = "NAME"
            cmbBookISBN.ValueMember = "ISBN"
            '将书籍改变标识置为真
            changeBookFlg = True
            cmbBookISBN_SelectedIndexChanged(Nothing, Nothing)
        End If
    End Sub
    Private Sub cmbBookISBN_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbBookISBN.SelectedIndexChanged
        If changeBookFlg Then
            Dim myBook As DataSet
            Dim strSQL As String
            '生成SQL语句
            strSQL = " select  NAME, AUTHOR , PRESS ,  PRICE , PRESSDATE   from BookInfo"
            strSQL = strSQL & " where ISBN=" & cmbBookISBN.SelectedValue
            '执行SQL语句，得到结果集
            myBook = DBManager.executeSelectQuery(strSQL, "BookInfo")
            '如果所选书籍在数据库中不存在，则将各输入框清空
            If myBook Is Nothing OrElse myBook.Tables(0).Rows.Count = 0 Then
                txtBookName.Text = ""
                txtAuthorName.Text = ""
                txtPress.Text = ""
                txtBookPrice.Text = ""
                Exit Sub
            End If
            '填充选中书籍各信息项
            With myBook.Tables("BookInfo").Rows(0)
                '书籍名称
                txtBookName.Text = .Item("NAME") & ""
                '作者姓名
                txtAuthorName.Text = .Item("AUTHOR") & ""
                '出版社
                txtPress.Text = .Item("PRESS") & ""
                '定价
                txtBookPrice.Text = .Item("PRICE") & ""
                '出版日期
                dtpPressDate.Value = .Item("PRESSDATE") & ""
            End With
        End If
    End Sub

    '删除书籍信息
    Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click
        Dim strSQL As String
        Dim ret As Boolean
        '生成SQL语句
        strSQL = "Delete from BookInfo where  ISBN=" & cmbBookISBN.SelectedValue & ""
        '执行SQL语句
        ret = DBManager.executeNonQuery(strSQL)
        If ret Then
            '如果删除成功，则提示成功信息并重新加载数据
            InfoMSG("书籍信息删除成功！")
            Dim myType As DataSet
            changeFlg = False
            changeBookFlg = False
            strSQL = "select code , name from BookType"
            myType = DBManager.executeSelectQuery(strSQL, "BookType")
            cmbBookType.DataSource = myType.Tables("BookType")
            cmbBookType.DisplayMember = "name"
            cmbBookType.ValueMember = "code"
            changeFlg = True
            cmbBookType_SelectedIndexChanged(Nothing, Nothing)
        Else
            '如果删除失败，提示失败信息
            ErrorMSG("书籍信息删除失败！")
        End If
    End Sub

    Private Sub BookEdit_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim myType As DataSet
        Dim strSQL As String
        changeFlg = False
        changeBookFlg = False
        '填充书籍类别信息
        strSQL = "select code , name from BookType"
        myType = DBManager.executeSelectQuery(strSQL, "BookType")
        cmbBookType.DataSource = myType.Tables("BookType")
        cmbBookType.DisplayMember = "name"
        cmbBookType.ValueMember = "code"

        changeFlg = True
        cmbBookType_SelectedIndexChanged(Nothing, Nothing)
    End Sub
    Private Function checkData() As Boolean
        '判断书名是否为空
        If txtBookName.Text.Trim = "" Then
            ErrorMSG("书名不允许为空！")
            Return False
        End If
        '判断作者是否为空
        If txtAuthorName.Text.Trim = "" Then
            ErrorMSG("作者不允许为空！")
            Return False
        End If
        '判断书籍类别是否为空
        If cmbBookType.Text.Trim = "" Then
            ErrorMSG("书籍种类不允许为空！")
            Return False
        End If
        '判断出版社是否为空
        If txtPress.Text.Trim = "" Then
            ErrorMSG("出版社不允许为空！")
            Return False
        End If
        '判断定价是否为空
        If txtBookPrice.Text.Trim = "" Then
            ErrorMSG("定价不允许为空！")
            Return False
        Else
            '判断定价是否为数字
            If Not IsNumeric(txtBookPrice.Text.Trim) Then
                ErrorMSG("定价必须为数字！")
                Return False
            End If
        End If
        Return True
    End Function
End Class