iText v 7 错误，"classes can only inherit from other classes" 在 "Inherits IDocumentReadyListener"

Question

如何解决 "classes can only inherit from other classes" 在 "Inherits IDocumentReadyListener" 的错误？这是在 VB.net 中使用 iText v7 api。我正在尝试从 pdf 拆分器获取字节数组。

Class ByteArrayPdfSplitter
    Inherits iText.Kernel.Utils.PdfSplitter

    Private currentOutputStream As MemoryStream

    Public Sub New(ByVal pdfDocument As iText.Kernel.Pdf.PdfDocument)
        MyBase.New(pdfDocument)
    End Sub

    Protected Overrides Function GetNextPdfWriter(ByVal documentPageRange As iText.Kernel.Utils.PageRange) As iText.Kernel.Pdf.PdfWriter
        currentOutputStream = New MemoryStream()
        Return New iText.Kernel.Pdf.PdfWriter(currentOutputStream)
    End Function

    Public ReadOnly Property CurrentMemoryStream As MemoryStream
        Get
            Return currentOutputStream
        End Get
    End Property

    Public Class DocumentReadyListender
        Inherits IDocumentReadyListener

        Private splitter As ByteArrayPdfSplitter

        Public Sub New(ByVal splitter As ByteArrayPdfSplitter)
            Me.splitter = splitter
        End Sub

        Public Sub DocumentReady(ByVal pdfDocument As iText.Kernel.Pdf.PdfDocument, ByVal pageRange As iText.Kernel.Utils.PageRange)
            pdfDocument.Close()
            Dim contents As Byte() = splitter.CurrentMemoryStream.ToArray()
            Dim pageNumber As String = pageRange.ToString()
        End Sub
    End Class

End Class

Answer 1

IDocumentReadyListener 不是 class，它是一个接口，每当你实现接口时，表明这一点的正确关键字是 Implements，而不是 Inherits。因此：

Public Class DocumentReadyListender
        Implements IDocumentReadyListener

有关界面的更多背景信息，请阅读 here。

iText v 7 错误，"classes can only inherit from other classes" 在 "Inherits IDocumentReadyListener"

iText v 7 error, "classes can only inherit from other classes" at "Inherits IDocumentReadyListener"

vb.net

itext7