ASP.NET 将字节合并到单个 PDF 文档时出现 PdfReader 异常 "The document has no pages."
ASP.NET PdfReader Exception While Merging Bytes to Single PDF Document "The document has no pages."
我总共有 9 列，所有列都有字节数据。在这 9 列中，7 列具有 IMAGE 数据类型，1 列具有 VARBINARY(MAX)。这 7 列有 JPG 的字节，1 列有 PDF 的字节。最后我需要将所有内容合并到一个 pdf 中。
如上图所示，我有一个函数，我在 List(Of Byte()) 变量中发送字节我得到两列的长度，但它在突出显示的行 Using reader = New PdfReader(p) 上给我错误“文档没有页面。”。这是什么错误，我应该如何解决？
下面是我的代码：
Dim mergedpdf as byte() = nothing,listoffilebytes As List(Of Byte()) = New List(Of Byte())(), schoolname As String = ""
Protected Sub Button1_Click(sender As Object, e As EventArgs)
MergeandDownload(3)
End Sub
Sub MergeandDownload(ByVal regid As Integer)
Using conn As New SqlConnection(constr)
Try
Using cmd As New SqlDataAdapter("SELECT b.schoolname,(case when a.[building] is null then '' else a.[building] end) AS building,a.[fire],a.[pollution],a.[chemical],a.[municipality],a.[traffic],a.[bylaws],a.[building_sketch],(case when a.[singlepdf] is null then '' else a.[singlepdf] end) AS singlepdf FROM [reg_documents] a inner join registration_master b on b.reg_schoolid = a.reg_schoolid where a.reg_schoolid = @regid", conn)
cmd.SelectCommand.Parameters.AddWithValue("@regid", regid)
conn.Open()
Using dsset As New DataSet()
cmd.Fill(dsset, "tabs")
If (dsset.Tables(0).Rows.Count > 0) Then
schoolname = dsset.Tables(0).Rows(0)("schoolname").ToString()
If (dsset.Tables(0).Rows(0)("building").ToString() <> "") Then
listoffilebytes.Add(System.Text.Encoding.ASCII.GetBytes(dsset.Tables(0).Rows(0)("building").ToString()))
End If
If (dsset.Tables(0).Rows(0)("singlepdf").ToString() <> "") Then
listoffilebytes.Add(System.Text.Encoding.ASCII.GetBytes(dsset.Tables(0).Rows(0)("singlepdf").ToString()))
End If
mergedpdf = concatAndAddContent(listoffilebytes)
End If
End Using
End Using
Catch ex As Exception
Finally
If ConnectionState.Open Then
conn.Close()
End If
End Try
End Using
If (mergedpdf.Length() > 0) Then
Response.Clear()
Response.Buffer = True
Response.Charset = ""
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ContentType = "application/pdf"
Response.AppendHeader("Content-Disposition", "attachment; filename=" + schoolname + ".pdf")
Response.BinaryWrite(mergedpdf)
Response.Flush()
Response.End()
End If
End Sub
Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
End Sub
Public Shared Function concatAndAddContent(ByVal pdfByteContent As List(Of Byte())) As Byte()
Using ms = New MemoryStream()
Using doc = New Document()
Using copy = New PdfSmartCopy(doc, ms)
doc.Open()
For Each p In pdfByteContent
Using reader = New PdfReader(p)
copy.AddDocument(reader)
End Using
Next
doc.Close()
End Using
End Using
Return ms.ToArray()
End Using
End Function
我找到了解决这个问题的方法，并且如下所示。分享我的代码
将上面的库导入为：
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
Imports iTextSharp.text
Imports System.IO
Imports iTextSharp.text.html.simpleparser
Imports iTextSharp.text.pdf
Imports System.Drawing
下面的代码会将存储在图像列中的 JPG 字节生成为 PDF，并将存储在 VARBINARY(MAX) 中的 PDF 字节生成为 PDF，然后将其全部合并到单个 PDF 文件中并下载：
Protected Sub Button1_Click(sender As Object, e As EventArgs)
MergeandDownload(123)
End Sub
Sub MergeandDownload(ByVal regid As Integer)
Using conn As New SqlConnection(constr)
Try
Using cmd As New SqlDataAdapter("SELECT b.schoolname,a.building,a.[fire] AS fire,a.[singlepdf] FROM [reg_documents] a inner join registration_master b on b.reg_schoolid = a.reg_schoolid where a.reg_schoolid = @regid", conn)
cmd.SelectCommand.Parameters.AddWithValue("@regid", regid)
conn.Open()
Using dsset As New DataSet()
cmd.Fill(dsset, "tabs")
If (dsset.Tables(0).Rows.Count > 0) Then
schoolname = Server.HtmlEncode(dsset.Tables(0).Rows(0)("schoolname").ToString())
Using _ms As New MemoryStream
Using _doc As New Document()
Using _copy As New PdfCopy(_doc, _ms)
_doc.Open()
If (Not IsDBNull(dsset.Tables(0).Rows(0)("building"))) Then
Dim _reader As PdfReader = New PdfReader(concatAndAddContent3(dsset.Tables(0).Rows(0)("building")))
Dim n As Integer = _reader.NumberOfPages
For _i As Integer = 0 To n - 1
_copy.AddPage(_copy.GetImportedPage(_reader, System.Threading.Interlocked.Increment(_i)))
Next
End If
If (Not IsDBNull(dsset.Tables(0).Rows(0)("fire"))) Then
Dim _reader As PdfReader = New PdfReader(concatAndAddContent3(dsset.Tables(0).Rows(0)("fire")))
Dim n As Integer = _reader.NumberOfPages
For _i As Integer = 0 To n - 1
_copy.AddPage(_copy.GetImportedPage(_reader, System.Threading.Interlocked.Increment(_i)))
Next
End If
If (Not IsDBNull(dsset.Tables(0).Rows(0)("singlepdf"))) Then
Dim _reader As PdfReader = New PdfReader(CType(dsset.Tables(0).Rows(0)("singlepdf"), Byte()))
Dim n As Integer = _reader.NumberOfPages
For _i As Integer = 0 To n - 1
_copy.AddPage(_copy.GetImportedPage(_reader, System.Threading.Interlocked.Increment(_i)))
Next
End If
End Using
End Using
mergedpdf = _ms.ToArray()
End Using
End If
End Using
End Using
Catch ex As Exception
Response.Write(ex.ToString())
Finally
If ConnectionState.Open Then
conn.Close()
End If
End Try
End Using
If (mergedpdf.Length() > 0) Then
Dim mst As MemoryStream = New MemoryStream(mergedpdf)
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment;filename=" & schoolname & "_MergedDoc_" & DateTime.Now.ToString() & ".pdf")
Response.Buffer = True
mst.WriteTo(Response.OutputStream)
Response.[End]()
End If
End Sub
Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
End Sub
Public Function concatAndAddContent3(ByVal _strimgBytes As Byte()) As Byte()
Using memoryStream As System.IO.MemoryStream = New System.IO.MemoryStream()
Dim base64 As String = Convert.ToBase64String(_strimgBytes)
newbytes = Convert.FromBase64String(base64)
Dim image As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(newbytes)
Dim document As Document = New Document(PageSize.A4, 0.0F, 0.0F, 0.0F, 0.0F)
Dim writer As PdfWriter = PdfWriter.GetInstance(document, memoryStream)
image.SetAbsolutePosition(10.0F, 10.0F)
image.ScaleAbsolute(500.0F, 800.0F)
document.Open()
document.Add(image)
document.Close()
newbytes = memoryStream.ToArray()
memoryStream.Close()
End Using
Return newbytes
End Function
我总共有 9 列，所有列都有字节数据。在这 9 列中，7 列具有 IMAGE 数据类型，1 列具有 VARBINARY(MAX)。这 7 列有 JPG 的字节，1 列有 PDF 的字节。最后我需要将所有内容合并到一个 pdf 中。
如上图所示，我有一个函数，我在 List(Of Byte()) 变量中发送字节我得到两列的长度，但它在突出显示的行 Using reader = New PdfReader(p) 上给我错误“文档没有页面。”。这是什么错误，我应该如何解决？
下面是我的代码：
Dim mergedpdf as byte() = nothing,listoffilebytes As List(Of Byte()) = New List(Of Byte())(), schoolname As String = ""
Protected Sub Button1_Click(sender As Object, e As EventArgs)
MergeandDownload(3)
End Sub
Sub MergeandDownload(ByVal regid As Integer)
Using conn As New SqlConnection(constr)
Try
Using cmd As New SqlDataAdapter("SELECT b.schoolname,(case when a.[building] is null then '' else a.[building] end) AS building,a.[fire],a.[pollution],a.[chemical],a.[municipality],a.[traffic],a.[bylaws],a.[building_sketch],(case when a.[singlepdf] is null then '' else a.[singlepdf] end) AS singlepdf FROM [reg_documents] a inner join registration_master b on b.reg_schoolid = a.reg_schoolid where a.reg_schoolid = @regid", conn)
cmd.SelectCommand.Parameters.AddWithValue("@regid", regid)
conn.Open()
Using dsset As New DataSet()
cmd.Fill(dsset, "tabs")
If (dsset.Tables(0).Rows.Count > 0) Then
schoolname = dsset.Tables(0).Rows(0)("schoolname").ToString()
If (dsset.Tables(0).Rows(0)("building").ToString() <> "") Then
listoffilebytes.Add(System.Text.Encoding.ASCII.GetBytes(dsset.Tables(0).Rows(0)("building").ToString()))
End If
If (dsset.Tables(0).Rows(0)("singlepdf").ToString() <> "") Then
listoffilebytes.Add(System.Text.Encoding.ASCII.GetBytes(dsset.Tables(0).Rows(0)("singlepdf").ToString()))
End If
mergedpdf = concatAndAddContent(listoffilebytes)
End If
End Using
End Using
Catch ex As Exception
Finally
If ConnectionState.Open Then
conn.Close()
End If
End Try
End Using
If (mergedpdf.Length() > 0) Then
Response.Clear()
Response.Buffer = True
Response.Charset = ""
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.ContentType = "application/pdf"
Response.AppendHeader("Content-Disposition", "attachment; filename=" + schoolname + ".pdf")
Response.BinaryWrite(mergedpdf)
Response.Flush()
Response.End()
End If
End Sub
Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
End Sub
Public Shared Function concatAndAddContent(ByVal pdfByteContent As List(Of Byte())) As Byte()
Using ms = New MemoryStream()
Using doc = New Document()
Using copy = New PdfSmartCopy(doc, ms)
doc.Open()
For Each p In pdfByteContent
Using reader = New PdfReader(p)
copy.AddDocument(reader)
End Using
Next
doc.Close()
End Using
End Using
Return ms.ToArray()
End Using
End Function
我找到了解决这个问题的方法，并且如下所示。分享我的代码
将上面的库导入为：
Imports System.Data
Imports System.Configuration
Imports System.Data.SqlClient
Imports iTextSharp.text
Imports System.IO
Imports iTextSharp.text.html.simpleparser
Imports iTextSharp.text.pdf
Imports System.Drawing
下面的代码会将存储在图像列中的 JPG 字节生成为 PDF，并将存储在 VARBINARY(MAX) 中的 PDF 字节生成为 PDF，然后将其全部合并到单个 PDF 文件中并下载：
Protected Sub Button1_Click(sender As Object, e As EventArgs)
MergeandDownload(123)
End Sub
Sub MergeandDownload(ByVal regid As Integer)
Using conn As New SqlConnection(constr)
Try
Using cmd As New SqlDataAdapter("SELECT b.schoolname,a.building,a.[fire] AS fire,a.[singlepdf] FROM [reg_documents] a inner join registration_master b on b.reg_schoolid = a.reg_schoolid where a.reg_schoolid = @regid", conn)
cmd.SelectCommand.Parameters.AddWithValue("@regid", regid)
conn.Open()
Using dsset As New DataSet()
cmd.Fill(dsset, "tabs")
If (dsset.Tables(0).Rows.Count > 0) Then
schoolname = Server.HtmlEncode(dsset.Tables(0).Rows(0)("schoolname").ToString())
Using _ms As New MemoryStream
Using _doc As New Document()
Using _copy As New PdfCopy(_doc, _ms)
_doc.Open()
If (Not IsDBNull(dsset.Tables(0).Rows(0)("building"))) Then
Dim _reader As PdfReader = New PdfReader(concatAndAddContent3(dsset.Tables(0).Rows(0)("building")))
Dim n As Integer = _reader.NumberOfPages
For _i As Integer = 0 To n - 1
_copy.AddPage(_copy.GetImportedPage(_reader, System.Threading.Interlocked.Increment(_i)))
Next
End If
If (Not IsDBNull(dsset.Tables(0).Rows(0)("fire"))) Then
Dim _reader As PdfReader = New PdfReader(concatAndAddContent3(dsset.Tables(0).Rows(0)("fire")))
Dim n As Integer = _reader.NumberOfPages
For _i As Integer = 0 To n - 1
_copy.AddPage(_copy.GetImportedPage(_reader, System.Threading.Interlocked.Increment(_i)))
Next
End If
If (Not IsDBNull(dsset.Tables(0).Rows(0)("singlepdf"))) Then
Dim _reader As PdfReader = New PdfReader(CType(dsset.Tables(0).Rows(0)("singlepdf"), Byte()))
Dim n As Integer = _reader.NumberOfPages
For _i As Integer = 0 To n - 1
_copy.AddPage(_copy.GetImportedPage(_reader, System.Threading.Interlocked.Increment(_i)))
Next
End If
End Using
End Using
mergedpdf = _ms.ToArray()
End Using
End If
End Using
End Using
Catch ex As Exception
Response.Write(ex.ToString())
Finally
If ConnectionState.Open Then
conn.Close()
End If
End Try
End Using
If (mergedpdf.Length() > 0) Then
Dim mst As MemoryStream = New MemoryStream(mergedpdf)
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment;filename=" & schoolname & "_MergedDoc_" & DateTime.Now.ToString() & ".pdf")
Response.Buffer = True
mst.WriteTo(Response.OutputStream)
Response.[End]()
End If
End Sub
Public Overrides Sub VerifyRenderingInServerForm(ByVal control As Control)
End Sub
Public Function concatAndAddContent3(ByVal _strimgBytes As Byte()) As Byte()
Using memoryStream As System.IO.MemoryStream = New System.IO.MemoryStream()
Dim base64 As String = Convert.ToBase64String(_strimgBytes)
newbytes = Convert.FromBase64String(base64)
Dim image As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(newbytes)
Dim document As Document = New Document(PageSize.A4, 0.0F, 0.0F, 0.0F, 0.0F)
Dim writer As PdfWriter = PdfWriter.GetInstance(document, memoryStream)
image.SetAbsolutePosition(10.0F, 10.0F)
image.ScaleAbsolute(500.0F, 800.0F)
document.Open()
document.Add(image)
document.Close()
newbytes = memoryStream.ToArray()
memoryStream.Close()
End Using
Return newbytes
End Function