Vb.net 为什么这个VB代码对我来说失败了？

表格代码：

Imports TechSupportData

Public Class frmOpenIncidents

Private Sub frmOpenIncidents_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim incidentList As List(Of Incident)
    Try
        incidentList = IncidentDB.GetIncidents
        If incidentList.Count > 0 Then
            Dim incident As Incident
            For i As Integer = 0 To incidentList.Count - 1
                incident = incidentList(i)
                lvIncidents.Items.Add(incident.ProductCode)
                lvIncidents.Items(i).SubItems.Add(incident.DateOpened)
                lvIncidents.Items(i).SubItems.Add(incident.CustomerID)
                lvIncidents.Items(i).SubItems.Add(incident.TechID)
                lvIncidents.Items(i).SubItems.Add(incident.Title)
            Next
        Else
            MessageBox.Show("All Incidents are taken care of")
            Me.Close()
        End If
    Catch ex As Exception
        MessageBox.Show(ex.Message, ex.GetType.ToString)
        Me.Close()
    End Try
End Sub
End Class

下面是与之合作的班级：

Imports System.Data.SqlClient

Public Class IncidentDB
    Public Shared Function GetIncidents() As List(Of IncidentDB)
        Dim incidentList As New List(Of IncidentDB)
        Dim connection As SqlConnection = TechSupportDB.GetConnection
        Dim selectStatement As String _
            = "SELECT CustomerID, ProductCode, TechID, DateOpened, Title" _
            & "FROM(Incidents)" _
            & "WHERE DateClosed IS NULL"
        Dim selectCommand As New SqlCommand(selectStatement, connection)
        Try
            connection.Open()
            Dim reader As SqlDataReader = selectCommand.ExecuteReader()
            Dim incident As Incident
            Do While reader.Read
                incident = New Incident
                incident.IncidentID = reader("IncidentID").ToString
                incident.CustomerID = reader("CustomerID").ToString
                incident.ProductCode = reader("ProductCode").ToString
                incident.DateOpened = reader("DateOpened").ToString
            Loop
            reader.Close()
        Catch ex As Exception
            Throw ex
        Finally
            connection.Close()
        End Try
        Return incidentList
    End Function
End Class

以下是我从Visual Studio得到的错误：

错误1：无法将“System.Collections.Generic.List（属于TechSupportData.IncidentDB）”类型的值转换为“System.Collections.Generic.List（属于TechSupportData.Incident）”。C:\Users\Cody\Desktop\School\Current\ITECH4269 Visual Basic\Assignment2CodyStewart\Assignment2CodySteawrt\Assignment2CodySteawrt\FRMOpenicients.vb 8 28 Assignment2CodySteawrt

---

非常感谢您提供的任何指导或建议。

在FRMOpenicients课程中，您已将事件列表定义为事件列表：

Dim incidentList As List(Of Incident)

然后设置它：

incidentList = IncidentDB.GetIncidents

但是IncidentDB方法被定义为返回事件*DB*的列表：

Public Shared Function GetIncidents() As List(Of IncidentDB)

解决方案可能是将第一个定义更改为

Dim incidentList As List(Of IncidentDB)

---

您需要为类选择一个名称—Incident或IncidentDB—并一致使用它来消除所有类似的错误。

这解决了该错误，谢谢！现在我遇到了这个问题：“TechSupportData.IncidentDB”类型的错误1值无法转换为“TechSupportData.Incident”。C:\Users\Cody\Desktop\School\Current\ITECH4269 Visual Basic\Assignment2CodyStewart\Assignment2CodySteawrt\Assignment2CodySteawrt\frmopeIncidents。vb 12 32 Assignment2Codysteawr类似于它的另一种方式：应该是

公共共享函数GetIncidents（）作为（事件）列表。

我怀疑。@Filburt-听起来很合理。@Cody-我添加了一个额外的注释。您似乎混合了对IncidentDB类和Incident类的引用。您可能只想使用其中一个，或者在两个之间有一个明确定义的转换方式，如果您需要这两个原因，这在发布的代码中并不明显。也可以考虑不同的命名空间，这样您就可以使用前缀来保持数据类的区别。