Question

我使用此代码使用itextsharp 5.0.6将我的aspx页面转换为pdf：

 Using ms = New MemoryStream()

        Dim Html As String = vbCr & vbLf & "<h1>h1</h1>" & vbCr & vbLf & "<p class=""bo"">A paragraph</p>    " & vbCr & vbLf & "<ul> " & vbCr & vbLf & "<li>one</li>   " & vbCr & vbLf & "<li>two</li>   " & vbCr & vbLf & "<li>three</li>   " & vbCr & vbLf & "</ul>"
        Dim Html1 As String = RenderControlToString(Page)

        Dim styles As New StyleSheet()
        styles.LoadStyle("bo", "size", "10")
        styles.LoadTagStyle(HtmlTags.H1, HtmlTags.FONT, "59")
        styles.LoadTagStyle(HtmlTags.H1, HtmlTags.COLOR, "#ff0000")
        styles.LoadTagStyle(HtmlTags.UL, HtmlTags.INDENT, "10")
        styles.LoadTagStyle(HtmlTags.LI, HtmlTags.LEADING, "16")

        Using document As New Document(PageSize.A4, 10.0F, 10.0F, 100.0F, 0.0F)
            document.SetPageSize(iTextSharp.text.PageSize.A4.Rotate())

            PdfWriter.GetInstance(document, ms)
            document.Open()

            document.Add(New Paragraph("this is atest"))
            document.Add(New Paragraph("this is a test"))
            Dim strB As New StringBuilder(Html1)
            Using sReader As TextReader = New StringReader(Html1.ToString())
                Dim list As List(Of IElement) = HTMLWorker.ParseToList(sReader, styles)
                For Each elm As IElement In list
                    document.Add(elm)
                Next
            End Using


        End Using

    End Using

但是我在这一行上一直收到错误，说对象引用没有设置为对象的实例：

 Dim list As List(Of IElement) = HTMLWorker.ParseToList(sReader, styles)

如果我在这行代码中从变量Html1更改为Html，它工作正常。

  Using sReader As TextReader = New StringReader(Html1.ToString())

知道如何修复此错误吗？这是功能：

  Private Function RenderControlToString(control As Control) As String
    Dim sb As New StringBuilder()
    Dim sw As New StringWriter(sb)
    Dim writer As New HtmlTextWriter(sw)

    control.RenderControl(writer)
    Return sb.ToString()
End Function

感谢您的帮助。

Answer 1

（评论移动回答）

iTextSharp的HTMLWorker已知<hr>标记存在问题。短期解决方案是删除这些标签，但长期解决方案是切换到支持这些标签的XMLWorker，并且正在积极开发和维护。

将aspx页面转换为html时出错（itextsharp 5.0.6）

1 个答案: