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我正在使用从数据库填充的数据表填充列表框。这是相关的代码。

Private Sub frmMainMenu_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'Load data we need from the database
        Dim commandCraneType As New OleDbCommand("SELECT Name FROM CraneType WHERE Girders = 'Single Girder'", gConnection)
        Dim adapterCraneType As New OleDbDataAdapter(commandCraneType)
        Dim dTableCraneType As New DataTable()
        'Fill datatables and controls
        adapterCraneType.Fill(dTableCraneType)
        lboCraneType.DataSource = dTableCraneType
        lboCraneType.DisplayMember = "Name"
End Sub

Private Sub lboCraneType_SelectedIndexChanged(sender As Object, e As EventArgs) Handles lboCraneType.SelectedIndexChanged
        'Set the gCraneType global variable!
        gCraneType = lboCraneType.SelectedItem
        Debug.Print(gCraneType)
End Sub

列表框正确地填充了数据库中名称字段中的文本值。但是，当我在列表框中选择该项目时，调试告诉我 gCraneType 已分配 System...DataRowView，并且我收到一个异常，说我无法将该类型转换为字符串。我不明白为什么名称在列表框中正确显示，但选择是一种数据类型。

感谢您提供的任何帮助:)

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1 回答 1

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改变：

Private Sub lboCraneType_SelectedIndexChanged(sender As Object, e As EventArgs) Handles lboCraneType.SelectedIndexChanged
        'Set the gCraneType global variable!
        gCraneType = lboCraneType.SelectedItem
        Debug.Print(gCraneType)
End Sub

至：

Private Sub lboCraneType_SelectedIndexChanged(sender As Object, e As EventArgs) Handles lboCraneType.SelectedIndexChanged
        'Set the gCraneType global variable!
        Dim drv As DataRowView = lboCraneType.SelectedItem
        gCraneType = drv("Name").ToString
End Sub

感谢您在 commnets 中的帮助。

于 2013-06-26T18:10:02.907 回答