无法使用供应商信息填充列表视图框

Question

当表单加载时，有一个组合框，您可以在其中选择GL帐户。选择一个，然后单击“获取供应商”按钮以加载供应商信息。我主要在form.vb上遇到代码问题。我需要使用供应商信息填充listview框，我不确定我做错了什么。我引用了应付款类库等。在form.vb上的vendor.count上获取错误。我没有在Payables.DB上输入数据库信息b / c我不确定它是什么。感谢。

    Public Class Vendor


Dim m_VendorName As Integer
Dim m_FirstName As String
Dim m_LastName As String
Dim m_City As String
Dim m_State As String



Public Sub New()

End Sub



Public Property VendorName() As String
    Get
        Return m_VendorName
    End Get
    Set(ByVal value As String)
        m_VendorName = value
    End Set
End Property

Public Property FirstName() As String
    Get
        Return m_FirstName
    End Get
    Set(ByVal value As String)
        m_FirstName = value
    End Set
End Property




Public Property LastName() As String
    Get
        Return m_LastName
    End Get
    Set(ByVal value As String)
        m_FirstName = value
    End Set
End Property

Public Property State() As String
    Get
        Return m_State
    End Get
    Set(value As String)
        m_State = value

    End Set
End Property

Public Property City() As String
    Get
        Return m_City
    End Get
    Set(value As String)
        m_City = value
    End Set
End Property

结束班

    Imports System.Data.SqlClient

Public Class VendorDB

Public Shared Function GetVendors() As List(Of Vendor)
    Dim vendorList As New List(Of Vendor)
    Dim connection As SqlConnection = PayablesDB.GetConnection
    Dim selectStatement As String =
        "SELECT VendorName, FirstName, Last Name, State, City " &
        "FROM Vendor " &
        "ORDER BY Description"
    Dim selectCommand As New SqlCommand(selectStatement, connection)
    Try
        connection.Open()
        Dim reader As SqlDataReader = selectCommand.ExecuteReader()
        Dim vendor As Vendor

        Do While reader.Read
            vendor = New Vendor
            vendor.VendorName = (reader("VendorName")).ToString
            vendor.FirstName = reader("Firstname").ToString
            vendor.LastName = (reader("LastName")).ToString
            vendor.State = (reader("State")).ToString
            vendor.City = (reader("City")).ToString
            vendorList.Add(vendor)
        Loop
        reader.Close()
    Catch ex As SqlException
        Throw ex
    Finally
        connection.Close()
    End Try
    Return vendorList
End Function

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   Public Class GLAccount

Private m_Description As String

Public Sub New()

End Sub

Public Property Description() As String
    Get
        Return m_Description
    End Get
    Set(ByVal value As String)
        m_Description = value
    End Set
End Property

    Imports System.Data.SqlClient

Public Class GLAccountDB

Public Shared Function GetGLAccountList() As List(Of GLAccount)
    Dim accountList As New List(Of GLAccount)
    Dim connection As SqlConnection = PayablesDB.GetConnection
    Dim selectStatement As String =
        "SELECT Description " &
        "FROM GLAccounts " &
        "ORDER BY Description"
    Dim selectCommand As New SqlCommand(selectStatement, connection)
    Try
        connection.Open()
        Dim reader As SqlDataReader = selectCommand.ExecuteReader()
        Dim account As GLAccount
        Do While reader.Read
            account = New GLAccount
            account.Description = reader("Description").ToString
            accountList.Add(account)
        Loop
        reader.Close()
    Catch ex As SqlException
        Throw ex
    Finally
        connection.Close()
    End Try
    Return accountList
End Function

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现在这就是我所提到的应付款（表格和验证员类）

    Public Class Validator
Public Shared Function IsPresent(control As Control) As Boolean
    Dim comboBox As ComboBox = CType(control, ComboBox)

    If comboBox.SelectedIndex = -1 Then
        MessageBox.Show(comboBox.Tag.ToString & " is a required field.")
        comboBox.Select()
        Return False
    Else
        Return True
    End If

End Function

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     Payables

Public Class Form1     Dim vendorList As List（供应商）     Dim accountList As List（Of GLAccount）

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    LoadComboBoxes()

End Sub

Private Sub LoadComboBoxes()
    accountList = GLAccountDB.GetGLAccountList
    cboAccounts.DataSource = accountList
    cboAccounts.DisplayMember = "Description"
End Sub


Private Sub btnGetVendors_Click(sender As Object, e As EventArgs) Handles btnGetVendors.Click
    Dim vendorList As List(Of Vendor)
    Try

        If Vendor.Count > 0 Then
            vendorList = VendorDB.GetVendors()

        Else
            MessageBox.Show("All invoices were paid in full")
        End If

    Catch ex As Exception

    End Try
End Sub



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

结束班