bookmaintenance.vb

图书管理系统

Imports System.Data.SqlClient
Public Class BookMaintenance
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents ComboBox1 As System.Windows.Forms.ComboBox
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents Label4 As System.Windows.Forms.Label
    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox
    Friend WithEvents Label5 As System.Windows.Forms.Label
    Friend WithEvents TextBox4 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label
        Me.ComboBox1 = New System.Windows.Forms.ComboBox
        Me.Label2 = New System.Windows.Forms.Label
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Label3 = New System.Windows.Forms.Label
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.Label4 = New System.Windows.Forms.Label
        Me.TextBox3 = New System.Windows.Forms.TextBox
        Me.Label5 = New System.Windows.Forms.Label
        Me.TextBox4 = New System.Windows.Forms.TextBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(56, 32)
        Me.Label1.Name = "Label1"
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "书籍名称"
        '
        'ComboBox1
        '
        Me.ComboBox1.Location = New System.Drawing.Point(184, 32)
        Me.ComboBox1.Name = "ComboBox1"
        Me.ComboBox1.Size = New System.Drawing.Size(144, 20)
        Me.ComboBox1.TabIndex = 1
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(56, 88)
        Me.Label2.Name = "Label2"
        Me.Label2.TabIndex = 2
        Me.Label2.Text = "作    者"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(184, 88)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(144, 21)
        Me.TextBox1.TabIndex = 3
        Me.TextBox1.Text = ""
        '
        'Label3
        '
        Me.Label3.Location = New System.Drawing.Point(56, 136)
        Me.Label3.Name = "Label3"
        Me.Label3.TabIndex = 4
        Me.Label3.Text = "出 版 社"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(184, 136)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(144, 21)
        Me.TextBox2.TabIndex = 5
        Me.TextBox2.Text = ""
        '
        'Label4
        '
        Me.Label4.Location = New System.Drawing.Point(56, 184)
        Me.Label4.Name = "Label4"
        Me.Label4.TabIndex = 6
        Me.Label4.Text = "书籍定价"
        '
        'TextBox3
        '
        Me.TextBox3.Location = New System.Drawing.Point(184, 184)
        Me.TextBox3.Name = "TextBox3"
        Me.TextBox3.Size = New System.Drawing.Size(144, 21)
        Me.TextBox3.TabIndex = 7
        Me.TextBox3.Text = ""
        '
        'Label5
        '
        Me.Label5.Location = New System.Drawing.Point(56, 232)
        Me.Label5.Name = "Label5"
        Me.Label5.TabIndex = 8
        Me.Label5.Text = "出版日期"
        '
        'TextBox4
        '
        Me.TextBox4.Location = New System.Drawing.Point(184, 232)
        Me.TextBox4.Name = "TextBox4"
        Me.TextBox4.Size = New System.Drawing.Size(144, 21)
        Me.TextBox4.TabIndex = 9
        Me.TextBox4.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(48, 296)
        Me.Button1.Name = "Button1"
        Me.Button1.TabIndex = 10
        Me.Button1.Text = "更新"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(152, 296)
        Me.Button2.Name = "Button2"
        Me.Button2.TabIndex = 11
        Me.Button2.Text = "删除"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(256, 296)
        Me.Button3.Name = "Button3"
        Me.Button3.TabIndex = 12
        Me.Button3.Text = "取消"
        '
        'BookMaintenance
        '
        Me.AcceptButton = Me.Button1
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.BackColor = System.Drawing.SystemColors.ActiveBorder
        Me.ClientSize = New System.Drawing.Size(384, 357)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox4)
        Me.Controls.Add(Me.Label5)
        Me.Controls.Add(Me.TextBox3)
        Me.Controls.Add(Me.Label4)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.Label3)
        Me.Controls.Add(Me.TextBox1)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.ComboBox1)
        Me.Controls.Add(Me.Label1)
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog
        Me.MaximizeBox = False
        Me.Name = "BookMaintenance"
        Me.Text = "书籍信息维护"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Private ID1 As Integer
    Public Function CheckData() As Boolean
        '验证数据的合法性
        If ComboBox1.Text = "" Then
            MessageBox.Show("书籍选项不能为空!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Return False
        End If
        If TextBox1.Text = "" Then
            MessageBox.Show("作者选项不能为空!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Return False
        End If
        If TextBox2.Text = "" Then
            MessageBox.Show("出版社选项不能为空!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Return False
        End If
        If TextBox3.Text = "" Then
            MessageBox.Show("书籍定价项不能为空!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Return False
        Else
            If Not IsNumeric(TextBox3.Text) Then
                MessageBox.Show("书籍选项必须为数字!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
                Return False
            End If
        End If
        If TextBox4.Text = "" Then
            MessageBox.Show("出版日期选项不能为空!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Return False
        End If
        Return True
    End Function
    Private Sub ReadDataToComboBox()
        Try
            If mycon.State = ConnectionState.Closed Then
                mycon.Open()
            End If
            Dim sqlstr As String = "select * from Book Where Flag='0'" '只有未借的书才有可能更新或修改，呵呵
            Dim myreader As SqlDataReader
            Dim mycom As New SqlCommand(sqlstr, mycon)
            myreader = mycom.ExecuteReader()
            While myreader.Read
                ComboBox1.Items.Add(myreader("Name"))
            End While
            myreader.Close()
            ComboBox1.SelectedIndex = -1
            mycon.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

    Private Sub BookMaintenance_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '将数据库里的book表里的内容读到ComboBox里来
        Call ReadDataToComboBox()
    End Sub
    '由一个字段获取其ID号
    Public Function GetID(ByVal s2 As String, ByVal s3 As String) As Integer
        Try
            If mycon.State = ConnectionState.Closed Then
                mycon.Open()
            End If
            Dim str As String
            Dim ID As Integer
            Dim table As New SqlParameter("@table", SqlDbType.VarChar, 10)
            Dim Name As New SqlParameter("@Name", SqlDbType.Int, 4)
            table.Value = s3
            Name.Value = s2
            str = "select * from @table Where Name=@Name"
            '  Dim da1 As New SqlDataAdapter(str, mycon)
            '  Dim myset1 As New DataSet
            '  da1.Fill(myset1, "Book")
            '    ID = myset1.Tables("Book").Rows(myset1.Tables("Book").Rows.Count - 1).Item("ID")'获取最高的ID号的代码
            Dim mycom1 As New SqlCommand(str, mycon) '可以节约内存吗？
            Dim myreader1 As SqlDataReader
            mycom1.Parameters.Add(table)
            mycom1.Parameters.Add(Name)
            myreader1 = mycom1.ExecuteReader
            While myreader1.Read
                ID = myreader1("ID")
            End While
            Return ID
            mycon.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Function

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        '更新按钮的代码
        '首先检验数据的合法性

        If Not CheckData() Then
            Exit Sub
        End If
        Try '取起ID
     
            '再次打开mycon
            If mycon.State = ConnectionState.Closed Then
                mycon.Open()
            End If
            Dim ID2 As New SqlParameter("@ID2", SqlDbType.Int, 4)
            ID2.Value = ID1
            Dim sqlstr As String = "update Book set Name='" & ComboBox1.Text & "' ,Anchor='" & TextBox1.Text & "',Publisher='" & TextBox2.Text & "',Price='" & TextBox3.Text & "',PublishDate='" & TextBox4.Text & "' Where ID=@ID2 and Flag='0'"
            Dim mycom As New SqlCommand(sqlstr, mycon)
            mycom.Parameters.Add(ID2)
            mycom.ExecuteNonQuery()
            MessageBox.Show("更新成功！", "恭喜", MessageBoxButtons.OK, MessageBoxIcon.Information)
            mycon.Close()
            '修改Book_HisTory中相应的字段
            mycon.Open()
            mycom = New SqlCommand("Update Book_HisTory Set BookName='" & ComboBox1.Text & "' Where BookID='" & ID1 & "'", mycon)
            mycom.ExecuteNonQuery()
            mycon.Close()
            MessageBox.Show("在Book_HisTory中更改也成功了!", "提醒", MessageBoxButtons.OK, MessageBoxIcon.Warning)
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        '删除按钮的代码
        '   If CheckData() = False Then
        '   Exit Sub
        '   End If
        Try
            If mycon.State = ConnectionState.Closed Then
                mycon.Open()
            End If
            Dim sqlstr As String = "delete from Book where Name='" & ComboBox1.Text & "' and Anchor='" & TextBox1.Text & "' and Publisher='" & TextBox2.Text & "' and Flag='0'"
            Dim mycom As New SqlCommand(sqlstr, mycon)
            mycom.ExecuteNonQuery()
            MessageBox.Show("删除成功！", "恭喜", MessageBoxButtons.OK, MessageBoxIcon.Information)
            mycon.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
        ComboBox1.Text = ""
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
        TextBox4.Text = ""
        ComboBox1.Focus()
        '在重新读数到ComBoBox1控件中，呵呵(有点失误)
        Call ReadDataToComboBox()
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        '取消按钮的代码
        Me.Close()
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
        '将数据读入各个控件中
        Try
            If mycon.State = ConnectionState.Closed Then
                mycon.Open()
            End If
            Dim sqlstr As String = "select Anchor,Publisher,Price,PublishDate from Book where Name='" & ComboBox1.Text & "' and Flag='0'"
            Dim myreader As SqlDataReader
            Dim mycom As New SqlCommand(sqlstr, mycon)
            myreader = mycom.ExecuteReader()
            While myreader.Read
                TextBox1.Text = myreader("Anchor")
                TextBox2.Text = myreader("Publisher")
                TextBox3.Text = myreader("Price")
                TextBox4.Text = myreader("PublishDate")
            End While
            mycon.Close()
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
        '取其ComboBox对应相的ID，呵呵，没想到真的很有用
        If mycon.State = ConnectionState.Closed Then
            mycon.Open()
        End If
        Dim str As String
        str = "select * from Book Where Name='" & ComboBox1.Text & "' and Flag='0'"
        Dim mycom1 As New SqlCommand(str, mycon)
        Dim myreader1 As SqlDataReader
        myreader1 = mycom1.ExecuteReader
        While myreader1.Read
            ID1 = myreader1("ID")
        End While
        mycon.Close()

    End Sub
End Class