假设有这么一段代码：
private
void
CreatePdf()
{
Document doc=new Document();
MemoryStream ms=new MemoryStream();
PdfWriter writer =PdfWriter.GetInstance(doc,ms);
doc.Open();
doc.Add(new Paragraph(DateTime.Now.ToLongDateString()));
doc.Close();
ViewPdf(ms);
}
private
void
ViewPdf(Stream fs)
{
byte[] buffer=new byte[fs.Length];
fs.Position=0;
fs.Read(buffer,0,(int)fs.Length);
Response.Clear();
Response.ContentType = "application/pdf";
Response.BinaryWrite(buffer);
Response.OutputStream.Flush();
Response.OutputStream.Close();
}
在调用CreatePdf()的时候碰到了如下错误：
Exception Details: System.ObjectDisposedException: Cannot access a closed Stream.
Source Error:
问题出在哪里了呢？从错误我可以知道我们准备操作的Stream已经关闭，这是因为iTextSharp自动关闭生成的Stream了，那有没有办法不关闭呢？
看了下面这段代码，也许就不用我说什么了：
private
void
Page_Load(
object
sender, System.EventArgs e)
{
//CreatePdf();
EditPDF();
}
private
void
EditPDF()
{
PdfReader reader =new PdfReader(@"e:\xml2PDF.pdf");
MemoryStream ms=new MemoryStream();
PdfStamper stamper=new PdfStamper(reader,ms);
stamper.Writer.CloseStream=false;
PdfContentByte cb=stamper.GetOverContent(1);
cb.Circle(250,250,50);
cb.SetColorFill(iTextSharp.text.Color.RED);
cb.SetColorStroke(iTextSharp.text.Color.WHITE);
cb.FillStroke();
stamper.Close();
ViewPdf(ms);
}
private
void
CreatePdf()
{
Document doc=new Document();
MemoryStream ms=new MemoryStream();
PdfWriter writer =PdfWriter.GetInstance(doc,ms);
writer.CloseStream=false;
doc.Open();
doc.Add(new Paragraph(DateTime.Now.ToLongDateString()));
doc.Close();
ViewPdf(ms);
}
private
void
ViewPdf(Stream fs)
{
byte[] buffer=new byte[fs.Length];
fs.Position=0;
fs.Read(buffer,0,(int)fs.Length);
fs.Close();
Response.Clear();
Response.ContentType = "application/pdf";
Response.BinaryWrite(buffer);
Response.OutputStream.Flush();
Response.OutputStream.Close();
}
原来PdfWriter有个熟悉就是让我们设置是否自动关闭Stream的，而默认是关闭的。
2006-12-01更新ViewPdf function
private
void
CreatePdf()
{
Document doc=new Document(); MemoryStream ms=new MemoryStream(); PdfWriter writer =PdfWriter.GetInstance(doc,ms); doc.Open(); doc.Add(new Paragraph(DateTime.Now.ToLongDateString())); doc.Close(); ViewPdf(ms); }
private
void
ViewPdf(Stream fs)
{ byte[] buffer=new byte[fs.Length]; fs.Position=0; fs.Read(buffer,0,(int)fs.Length); Response.Clear(); Response.ContentType = "application/pdf"; Response.BinaryWrite(buffer); Response.OutputStream.Flush(); Response.OutputStream.Close(); }
在调用CreatePdf()的时候碰到了如下错误：
Cannot access a closed Stream.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.Exception Details: System.ObjectDisposedException: Cannot access a closed Stream.
Source Error:
Line 58: private void ViewPdf(Stream fs) |
问题出在哪里了呢？从错误我可以知道我们准备操作的Stream已经关闭，这是因为iTextSharp自动关闭生成的Stream了，那有没有办法不关闭呢？
看了下面这段代码，也许就不用我说什么了：
private
void
Page_Load(
object
sender, System.EventArgs e)
{ //CreatePdf(); EditPDF(); }
private
void
EditPDF()
{ PdfReader reader =new PdfReader(@"e:\xml2PDF.pdf"); MemoryStream ms=new MemoryStream(); PdfStamper stamper=new PdfStamper(reader,ms); stamper.Writer.CloseStream=false; PdfContentByte cb=stamper.GetOverContent(1); cb.Circle(250,250,50); cb.SetColorFill(iTextSharp.text.Color.RED); cb.SetColorStroke(iTextSharp.text.Color.WHITE); cb.FillStroke(); stamper.Close(); ViewPdf(ms); }
private
void
CreatePdf()
{ Document doc=new Document(); MemoryStream ms=new MemoryStream(); PdfWriter writer =PdfWriter.GetInstance(doc,ms); writer.CloseStream=false; doc.Open(); doc.Add(new Paragraph(DateTime.Now.ToLongDateString())); doc.Close(); ViewPdf(ms); }
private
void
ViewPdf(Stream fs)
{ byte[] buffer=new byte[fs.Length]; fs.Position=0; fs.Read(buffer,0,(int)fs.Length); fs.Close(); Response.Clear(); Response.ContentType = "application/pdf"; Response.BinaryWrite(buffer); Response.OutputStream.Flush(); Response.OutputStream.Close(); }
原来PdfWriter有个熟悉就是让我们设置是否自动关闭Stream的，而默认是关闭的。
2006-12-01更新ViewPdf function
private
void
ViewPdf(Stream fs)
{
byte [] buffer = new byte [fs.Length];
fs.Position = 0 ;
fs.Read(buffer, 0 , ( int )fs.Length);
Response.Clear();
// Response.AddHeader("Content-Disposition", "attachment;FileName=out.pdf");
Response.AddHeader( " Content-Length " ,fs.Length.ToString());
Response.ContentType = " application/pdf " ;
fs.Close();
Response.BinaryWrite(buffer);
Response.OutputStream.Flush();
Response.OutputStream.Close();
}
{
byte [] buffer = new byte [fs.Length];
fs.Position = 0 ;
fs.Read(buffer, 0 , ( int )fs.Length);
Response.Clear();
// Response.AddHeader("Content-Disposition", "attachment;FileName=out.pdf");
Response.AddHeader( " Content-Length " ,fs.Length.ToString());
Response.ContentType = " application/pdf " ;
fs.Close();
Response.BinaryWrite(buffer);
Response.OutputStream.Flush();
Response.OutputStream.Close();
}
如果需要下载而不是在IE中看的话，请把Response.AddHeader("Content-Disposition", "attachment;FileName=out.pdf");前的注释去掉，并替换上你想要的名字。
如果不指定Response.AddHeader("Content-Length",fs.Length.ToString());，IE会把网页内容也输出，在PDF后面，此时显示生成的PDF被破坏（这个说是IE的一个bug，我也不清楚）
如果附件名为中文：
Response.AddHeader("Content-Disposition", "attachment;FileName="+HttpUtility.UrlEncode("中文.pdf"));
内嵌显示PDF
Response.AddHeader("Content-Disposition", "inline;FileName=out.pdf");
更多这方面的信息google上搜索吧。
本文转自RubyPdf 的中文博客博客园博客，原文链接：http://www.cnblogs.com/hardrock/archive/2006/02/23/336397.html，如需转载请自行联系原作http://www.cnblogs.com/hardrock/archive/2006/05/17/402654.html
