[ObjectDisposedException: Cannot access a closed Stream.]
System.IO.__Error.StreamIsClosed() +53
System.IO.MemoryStream.Read(Byte[] buffer,Int32 offset,Int32 count)
+11411219 System.Web.Mvc.FileStreamResult.WriteFile(HttpResponseBase response)
+81 System.Web.Mvc.FileResult.ExecuteResult(ControllerContext context) +168
System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext
controllerContext,ActionResult actionResult) +13
在调用之后
//Byte[] bytes;
using ( var ms = new MemoryStream() )
{
using ( var doc = new Document() )
{
using ( var writer = PdfWriter.GetInstance(doc,ms) )
{
doc.Open();
//var example_html = @"<p>This <em>is </em><span class=""headline"" style=""text-decoration: underline;"">some</span> <strong>sample <em> text</em></strong><span style=""color: red;"">!!!</span></p>";
var example_html = System.IO.File.ReadAllText(Path.Combine(Server.MapPath("~/EmailTemplates"),"template.html"));
var example_css = @".headline{font-size:200%}";
using ( var srHtml = new StringReader(example_html) )
{
iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer,doc,srHtml);
}
using ( var msCss = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(example_css)) )
{
using (var msHtml = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(example_html)))
{
iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer,msHtml,msCss);
}
}
doc.Close();
}
}
//bytes = ms.ToArray();
return File(ms,"application/pdf","Test.pdf");
}
我读过MemoryStream – Cannot access a closed Stream,但那不是同一个场景,因为我没有使用StreamReader
编辑：仍然没有使用
[OutputCache(NoStore = true,Duration = 0)]
public ActionResult Run()
{
Byte[] bytes;
var ms = new MemoryStream();
try
{
using (var doc = new Document())
{
using (var writer = PdfWriter.GetInstance(doc,ms))
{
writer.CloseStream = false;
doc.Open();
var example_html = @"<p>This <em>is </em><span class=""headline"" style=""text-decoration: underline;"">some</span> <strong>sample <em> text</em></strong><span style=""color: red;"">!!!</span></p>";
//var example_html = System.IO.File.ReadAllText(Path.Combine(Server.MapPath("~/EmailTemplates"),"LinkEmailTemplate.html"));
var example_css = @".headline{font-size:200%}";
using (var msCss = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(example_css)))
{
using (var msHtml = new MemoryStream(System.Text.Encoding.UTF8.GetBytes(example_html)))
{
iTextSharp.tool.xml.XMLWorkerHelper.GetInstance().ParseXHtml(writer,msCss);
}
}
doc.Close();
}
}
bytes = ms.ToArray();
ms.Position = 0;
return File(ms,"Test.pdf");
}
catch
{
ms.Dispose();
throw;
}
}
解决方法
您不需要处理MemoryStream. File返回的FileStreamResult对象(ms,“application / pdf”,“Test.pdf”);将dispose it after rendering.实际发送流数据的代码是：
protected async override Task WriteFileAsync(HttpResponse response)
{
var outputStream = response.Body;
using (FileStream)
{
var bufferingFeature = response.HttpContext.Features.Get<IHttpBufferingFeature>();
bufferingFeature?.DisableResponseBuffering();
await FileStream.CopyToAsync(outputStream,BufferSize);
}
}
您可以使用以下块替换此块：
var ms = new MemoryStream();
try
{
//..
//From Igor's comment. FileStreamResult won't reset the stream position itself
ms.Position=0;
return File(ms,"Test.pdf");
}
catch
{
ms.Dispose();
throw;
}
确保在发生错误时丢弃流.
UPDATE
正如Igor所提到的,并且正如源代码所示,FileStreamResult不会重置流位置.在调用返回文件(…)之前,你必须将它设置为0
