机房重构-组合查询（模板方法）

前言：

组合查询用到了模板方法，因为有三个这样的窗体是差不多的，因此咱们直接套用设计模式中的模板方法去解决这样的问题。

内容：

UI层代码：

Public Class frmGroupQuery

    '用于接收文本框或时间控件的内容
    Public txtContent1 As String = ""
    Public txtContent2 As String = ""
    Public txtContent3 As String = ""

    Protected GroupQuery As New Entity.EntityGQuery  '定义一个组合查询实体

    Private Sub frmGroupQuery_Load(sender As Object, e As EventArgs) Handles MyBase.Load


        '操作符
        cmbOperation1.Items.Add(">")
        cmbOperation1.Items.Add("<")
        cmbOperation1.Items.Add("=")
        cmbOperation1.Items.Add("<>")

        cmbOperation2.Items.Add(">")
        cmbOperation2.Items.Add("<")
        cmbOperation2.Items.Add("=")
        cmbOperation2.Items.Add("<>")

        cmbOperation3.Items.Add(">")
        cmbOperation3.Items.Add("<")
        cmbOperation3.Items.Add("=")
        cmbOperation3.Items.Add("<>")
        '关系
        cmbRelation1.Items.Add("与")
        cmbRelation1.Items.Add("或")

        cmbRelation2.Items.Add("与")
        cmbRelation2.Items.Add("或")

        '时间控件不可见，只有当选择日期是可见
        DTP1.Visible = False
        DTP2.Visible = False
        DTP3.Visible = False

        



        '窗体加载，只有第一行是可用的
        cmbField2.Enabled = False
        cmbField3.Enabled = False
        cmbOperation2.Enabled = False
        cmbOperation3.Enabled = False

        cmbRelation2.Enabled = False
        txt2.Enabled = False
        txt3.Enabled = False
        '当选中dgvGroupQuery控件就选中行
        dgvGroupQuery.SelectionMode = DataGridViewSelectionMode.FullRowSelect '选择一整行

        Dim i As Integer
        For i = 0 To dgvGroupQuery.Columns.Count - 1
            dgvGroupQuery.Columns(i).Width = DataGridViewAutoSizeColumnMode.AllCells
        Next
    End Sub


    Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
        Me.Close()
    End Sub


    Private Sub Rdim()

        ReDim Preserve arrayControl(10)       '重定义数组维数 

        '初始化数组
        arrayControl(0) = New Term(cmbField1, "卡号")
        arrayControl(3) = New Term(cmbField2, "充值金额")
        arrayControl(6) = New Term(cmbField3, "学号")
        arrayControl(1) = New Term(cmbOperation1, "姓名")
        arrayControl(4) = New Term(cmbOperation2, "年纪")
        arrayControl(7) = New Term(cmbOperation3, "专业")
        arrayControl(2) = New Term(txt1, "学院")
        arrayControl(5) = New Term(txt2, "性别")
        arrayControl(8) = New Term(txt3, "类型")
        arrayControl(9) = New Term(cmbRelation1, "状态")
        arrayControl(10) = New Term(cmbRelation2, "状态1")

    End Sub
   
    '清空
    Private Sub BtnClear_Click(sender As Object, e As EventArgs) Handles BtnClear.Click
        Call Rdim()
        If AllEmpty(arrayControl) Then
            Exit Sub
        End If

        dgvGroupQuery.DataSource = ""
    End Sub

    '定义虚函数，将控件中文字转换为数据库中的字段
    Public Overridable Function GetDBName(ByVal control As String) As String
        Return ""
    End Function

    '定义虚函数，获取表名
    Protected Overridable Function GetTable() As String
        Return ""
    End Function

    '定义虚函数，把标题显示出来
    Protected Overridable Sub Todgv()
        '设置列宽
        dgvGroupQuery.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.AllCells

    End Sub



    Private Sub BtnQuery_Click(sender As Object, e As EventArgs) Handles BtnQuery.Click
        If cmbField1.Text = "上机日期" Or cmbField1.Text = "下机日期" Then
            txtContent1 = Format(DTP1.Value, "yyyy-MM-dd HH:mm:ss")
        Else          
            txtContent1 = txt1.Text
        End If

        If cmbField2.Text = "上机日期" Or cmbField2.Text = "下机日期" Then
            txtContent2 = Format(DTP2.Value, "yyyy-MM-dd HH:mm:ss")
        Else
            txtContent2 = txt2.Text
        End If

        If cmbField3.Text = "上机日期" Or cmbField3.Text = "下机日期" Then
            txtContent3 = Format(DTP3.Value, "yyyy-MM-dd HH:mm:ss")
        Else
            txtContent3 = txt3.Text
        End If




        '第一关系为空
        If cmbRelation1.Text = "" Then
            If cmbField1.Text = "" Or cmbOperation1.Text = "" Or txtContent1 = "" Then
                MsgBox("请检查第一行条件是否完整！", , "提示")
                Exit Sub
            End If
        End If

        '第一个关系不为空
        If cmbRelation1.Text <> "" Then
            If cmbField2.Text = "" Or cmbOperation2.Text = "" Or txtContent2 = "" Then
                MsgBox("请检查第二行条件是否完整！", , "提示")
                Return
            End If
        End If

        If cmbRelation2.Text <> "" Then
            If cmbField3.Text = "" Or cmbOperation3.Text = "" Or txtContent3 = "" Then
                MsgBox("请检查第三行条件是否完整！", , "提示")
                Return
            End If
        End If

        GroupQuery.tableName = GetTable()

        GroupQuery.cmbField1 = GetDBName(cmbField1.Text.Trim())
        GroupQuery.cmbField2 = GetDBName(cmbField2.Text.Trim())
        GroupQuery.cmbField3 = GetDBName(cmbField3.Text.Trim())

        GroupQuery.cmbOperation1 = cmbOperation1.Text.Trim()
        GroupQuery.cmbOperation2 = cmbOperation2.Text.Trim()
        GroupQuery.cmbOperation3 = cmbOperation3.Text.Trim()


        GroupQuery.txtContent1 = txtContent1
        GroupQuery.txtContent2 = txtContent2
        GroupQuery.txtContent3 = txtContent3

        GroupQuery.cmbRelation1 = GetDBName(cmbRelation1.Text.Trim())
        GroupQuery.cmbRelation2 = GetDBName(cmbRelation2.Text.Trim())

        Dim table As New DataTable
        Dim facade As New Facade.GroupQueryFacade
        table = facade.selectGQFacade(GroupQuery)

        If (table.Rows.Count = 0) Then
            MsgBox("没有符合条件的记录，请重新设置查询条件", , "提示")
            dgvGroupQuery.DataSource = Nothing
        Else
            Call Todgv()
        End If


    End Sub



    '第一个组合关系改变，第二行可用
    Private Sub cmbRelation1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cmbRelation1.SelectedIndexChanged
        cmbField2.Enabled = True
        cmbOperation2.Enabled = True
        txt2.Enabled = True
        cmbRelation2.Enabled = True


    End Sub


    '第二个组合关系改变，第三行可用
    Private Sub cmbRelation2_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cmbRelation2.SelectedIndexChanged
        cmbField3.Enabled = True
        cmbOperation3.Enabled = True
        txt3.Enabled = True
    End Sub




    '针对查询与日期、时间有关的问题  
    Private Sub cmbField1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cmbField1.SelectedIndexChanged
        If cmbField1.Text = "上机日期" Or cmbField1.Text = "下机日期" Then
            DTP1.Format = DateTimePickerFormat.Custom
            DTP1.Visible = True
            txt1.Visible = False
            txtContent1 = Format(DTP1.Value, "yyyy-MM-dd HH:mm:ss")
        Else
            DTP1.Visible = False
            txt1.Visible = True
            txtContent1 = txt1.Text
        End If

    End Sub

    '针对查询与日期、时间有关的问题  
    Private Sub cmbField2_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cmbField2.SelectedIndexChanged

        If cmbField2.Text = "上机日期" Or cmbField2.Text = "下机日期" Then
            DTP2.Format = DateTimePickerFormat.Custom
            DTP2.Visible = True
            txt2.Visible = False
            txtContent2 = Format(DTP2.Value, "yyyy-MM-dd HH:mm:ss")
        Else
            DTP2.Visible = False
            txt2.Visible = True
            txtContent2 = txt2.Text
        End If


    End Sub
    '针对查询与日期、时间有关的问题  
    Private Sub cmbField3_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cmbField3.SelectedIndexChanged
        If cmbField3.Text = "上机日期" Or cmbField3.Text = "下机日期" Then
            DTP3.Format = DateTimePickerFormat.Custom
            DTP3.Visible = True
            txt3.Visible = False
            txtContent3 = Format(DTP3.Value, "yyyy-MM-dd HH:mm:ss")
        Else
            DTP3.Visible = False
            txt3.Visible = True
            txtContent3 = txt3.Text
        End If





    End Sub



End Class