Question

我正在尝试检索构造函数中没有被请求作为参数的其他足球属性（交叉，运球，整理，控球） - reportID，playerID和评论都是必需的。

有超过20个足球属性，所以我只是将前几个属性包括在内以便于阅读。

报告类：

Public Class Report

Public Sub New(ByVal reportID As Integer, ByVal playerID As Integer, ByVal comments As String)

        _ReportID = reportID
        _PlayerID = playerID
        _Comments = comments

    End Sub

    Private _ReportID As Integer = 0
    Private _PlayerID As Integer = 0
    Private _Comments As String = ""

    Private _Crossing As Integer = 0
    Private _Dribbling As Integer = 0
    Private _Finishing As Integer = 0
    Private _BallControl As Integer = 0

Public Property ReportID() As Integer
        Get
            Return _ReportID
        End Get
        Set(ByVal value As Integer)
            _ReportID = value
        End Set
    End Property

    Public Property PlayerID() As Integer
        Get
            Return _PlayerID
        End Get
        Set(ByVal value As Integer)
            _PlayerID = value
        End Set
    End Property

    Public Property Comments() As String
        Get
            Return _Comments
        End Get
        Set(ByVal value As String)
            _Comments = value
        End Set
    End Property

    Public Property Crossing() As Integer
        Get
            Return _Crossing
        End Get
        Set(ByVal value As Integer)
            _Crossing = value
        End Set
    End Property

    Public Property Dribbling() As Integer
        Get
            Return _Dribbling
        End Get
        Set(ByVal value As Integer)
            _Dribbling = value
        End Set
    End Property

    Public Property Finishing() As Integer
        Get
            Return _Finishing
        End Get
        Set(ByVal value As Integer)
            _Finishing = value
        End Set
    End Property

    Public Property BallControl() As Integer
        Get
            Return _BallControl
        End Get
        Set(ByVal value As Integer)
            _BallControl = value
        End Set
    End Property

End Class

下面我意识到我只是将reportID，playerID和注释添加到我的typeList中，这就是为什么我为其他属性获取全部0的原因。如何访问属性？

检索数据：

Private Function retrieveReport() As List(Of Report)

        Dim typeList As New List(Of Report)
        Dim Str As String = "SELECT * FROM Report ORDER BY PlayerID"
        Try
            Using conn As New SqlClient.SqlConnection(DBConnection)
                conn.Open()
                Using cmdQuery As New SqlClient.SqlCommand(Str, conn)
                    Using drResult As SqlClient.SqlDataReader = cmdQuery.ExecuteReader()
                        While drResult.Read
                            typeList.Add(New Report(drResult("ReportID"), drResult("PlayerID"), drResult("Comments")))
                        End While                   
                    End Using 'Automatically closes connection
                End Using
            End Using

        Catch ex As Exception
            MsgBox("Report Exception: " & ex.Message & vbNewLine & Str)
        End Try

        Return typeList
    End Function

    Private Sub setReport()

        For Each rpt As Report In retrieveReport()

            '*****General Information
            UC_Menu_Scout1.txtComments.Text = rpt.Comments

            '*****Technical
            UC_Menu_Scout1.UcAttributes1.lblXCrossing.Text = rpt.Crossing
            UC_Menu_Scout1.UcAttributes1.lblXDribbling.Text = rpt.Dribbling
            UC_Menu_Scout1.UcAttributes1.lblXFinishing.Text = rpt.Finishing
            UC_Menu_Scout1.UcAttributes1.lblXBallControl.Text = rpt.BallControl
            UC_Menu_Scout1.UcAttributes1.lblXPassing.Text = rpt.Passing
            UC_Menu_Scout1.UcAttributes1.lblXHeadingAccuracy.Text = rpt.HeadingAccuracy
            UC_Menu_Scout1.UcAttributes1.lblXMarking.Text = rpt.Marking
            UC_Menu_Scout1.UcAttributes1.lblXTackling.Text = rpt.Tackling
            '*****Mental
            UC_Menu_Scout1.UcAttributes1.lblXAggression.Text = rpt.Aggression
            UC_Menu_Scout1.UcAttributes1.lblXPositioning.Text = rpt.Positioning
            UC_Menu_Scout1.UcAttributes1.lblXAnticipation.Text = rpt.Anticipation
            UC_Menu_Scout1.UcAttributes1.lblXComposure.Text = rpt.Composure
            UC_Menu_Scout1.UcAttributes1.lblXVision.Text = rpt.Vision
            UC_Menu_Scout1.UcAttributes1.lblXTeamwork.Text = rpt.Teamwork
            UC_Menu_Scout1.UcAttributes1.lblXWorkRate.Text = rpt.WorkRate
            '*****Physical
            UC_Menu_Scout1.UcAttributes1.lblXPace.Text = rpt.Pace
            UC_Menu_Scout1.UcAttributes1.lblXBalance.Text = rpt.Balance
            UC_Menu_Scout1.UcAttributes1.lblXJumping.Text = rpt.Jumping
            UC_Menu_Scout1.UcAttributes1.lblXStrength.Text = rpt.Strength
            UC_Menu_Scout1.UcAttributes1.lblXStamina.Text = rpt.Stamina

        Next

    End Sub

我想这并不难，所以请各位帮忙！

Answer 1

要向属性添加值，请使用With：

typeList.Add(New Report(drResult("ReportID"), drResult("PlayerID"), drResult("Comments")) With {.BallControl = drResult("BallControl"), .Dribbling = drResult("Dribbling")})

Answer 2

您需要将未提供的属性值作为参数分配给构造函数，或者可以向构造函数添加参数。试试这个 - 而不是像这样调用构造函数：

typeList.Add(New Report(drResult("ReportID"), drResult("PlayerID"), drResult("Comments")))

相反，请执行此操作：

dim rep = New Report(drResult("ReportID"), drResult("PlayerID"), drResult("Comments"))
    .Crossing = drResult("Crossing")
    'additional property assignments
With rep

End With

typeList.Add(rep)

如何访问构造函数外部的类属性

2 个答案: