I'm trying to create a scanning solution. Basically the user is physically scanning a page. The printer is making an API call, passing in the binary data of the scan in the body.
I'm trying to save this as a PDF on the server, but when I go to open the file, i'm getting an error "There is an error while reading a stream".
var bodyStream = new StreamReader(HttpContext.Current.Request.InputStream);
bodyStream.BaseStream.Seek(0, SeekOrigin.Begin);
var bodyText = bodyStream.ReadToEnd();
string pathToFiles = HttpContext.Current.Server.MapPath("~\\UploadedFiles\\WriteLines.pdf");
try
{
using (StreamWriter outputFile = new StreamWriter(pathToFiles, false))
{
outputFile.WriteLine(bodyText);
}
HttpContext.Current.Response.ContentType = "application/pdf";
}
catch (Exception ex)
{
throw (ex);
}
This is just testing something, and I have permissions etc for writing the file, it's just not creating a valid file.
Any thoughts on what I should use? I have looked into some libraries, but they don't seem to cover what i'm after
StreamReader.ReadToEnd convert bytes to string in particular encoding (UTF8 by default). I don't think this work for PDF.
You need copy bytes directly in the output file :
var bodyStream = HttpContext.Current.Request.InputStream;
bodyStream.Seek(0, SeekOrigin.Begin);
string pathToFiles = HttpContext.Current.Server.MapPath("~\\UploadedFiles\\WriteLines.pdf");
using (FileStream outputFile = File.Create(pathToFiles))
{
bodyStream.CopyTo(outputFile);
}
Related
I am downloading a pdf file using HttpWebRequest object and write the content directly to a FileStream from a response stream, using all "using" blocks and also the .Close method right after the data is copied.
And the next step, I need to extract some text from that pdf file by using some 3rd party library (iText7) but it can't access the file.
At first, I thought it was the iText7-related issue but then I realized it doesn't seem so because I can't even delete the file from file explorer, getting "file in use" error by my own app.
Here's the sample code:
HttpWebRequest webReq = (HttpWebRequest)HttpWebRequest.Create(url);
webReq.AllowAutoRedirect = true;
webReq.CookieContainer = Cookies;
webReq.UserAgent = UserAgent;
webReq.Referer = Referrer;
webReq.Method = WebRequestMethods.Http.Get;
using (HttpWebResponse response = (HttpWebResponse)webReq.GetResponse())
{
using (Stream httpResponseStream = response.GetResponseStream())
{
using (FileStream output = File.Create(file1))
{
httpResponseStream.CopyTo(output);
output.Close();
}
httpResponseStream.Close();
response.Close();
Cookies = webReq.CookieContainer;
}
}
GC.Collect();
ExtractPDFDoc(file1);//error throws in this function and the exception.message is "Cannot open document."
Console.WriteLine("now waiting to let you check the file is in use? try delete it manually...");
Console.ReadKey(); //added this line to ensure that file is actually in use. I can't even delete the file manually from windows file explorer at this time. But, interestingly, Acrobat Reader can OPEN the file when I double click, which makes me thing that Adobe and iText7 uses different methods to open the pdf file - but anyway - I can't help it tho.
Can you please help what is wrong here?
For those who wants to see the ExtractPDFDoc() method:
public static object ExtractPDFDoc(string filename)
{
iText.Kernel.Pdf.PdfReader pdfReader = null;
iText.Kernel.Pdf.PdfDocument pdfDocument = null;
try
{
pdfReader = new iText.Kernel.Pdf.PdfReader(filename);
pdfDocument = new iText.Kernel.Pdf.PdfDocument(pdfReader);
}
catch (Exception ex)
{
pdfReader = null;
pdfDocument = null;
return new Exception(string.Format("ExtractPDFDoc() failed on file '{0}' with message '{1}'", filename, ex.Message));
//this is where I get the error, ex.Message is 'Cannot open document.'
//however, I can open it in Adobe Reader but I can't delete it before closing my app.
}
}
If I remember correctly, the iText objects are all IDisposable, so you should be sure to dispose of them as well. Also, I don't know why you're returning an exception instead of just throwing it.
public static object ExtractPDFDoc(string filename)
{
iText.Kernel.Pdf.PdfReader pdfReader = null;
iText.Kernel.Pdf.PdfDocument pdfDocument = null;
try
{
pdfReader = new iText.Kernel.Pdf.PdfReader(filename);
pdfDocument = new iText.Kernel.Pdf.PdfDocument(pdfReader);
}
catch (Exception ex)
{
throw new Exception(string.Format("ExtractPDFDoc() failed on file '{0}' with message '{1}'", filename, ex.Message), ex);
}
finally
{
pdfReader?.Dispose();
pdfDocument?.Dispose();
}
}
Unrelated to that, you can also stack your using statements instead of nesting them.
using (HttpWebResponse response = (HttpWebResponse)webReq.GetResponse())
using (Stream httpResponseStream = response.GetResponseStream())
using (FileStream output = File.Create(file1))
{
// do stuff
}
I'm deeply sorry, thanks to #howcheng, I realized that it was the iText7 which leaves the file open after it's failed to open the document because of one of it's dependency files was missing in the output folder.
It's clear that I should do a .Close() on iText7 objects on exception to avoid false perceptions such as this.
Thanks for all your help.
I build a client server application for uploading file from a client folder to server.
My server WebMethod for uploading follows -
[WebMethod]
public string UploadFile(byte[] f, string fileName)
{
// the byte array argument contains the content of the file
// the string argument contains the name and extension
// of the file passed in the byte array
new general().logError("UploadFile " + fileName);
try
{
// instance a memory stream and pass the
// byte array to its constructor
MemoryStream ms = new MemoryStream(f);
FileStream fs = new FileStream(System.Web.Hosting.HostingEnvironment.MapPath
("~/data/") + fileName, FileMode.Create);
// write the memory stream containing the original
// file as a byte array to the filestream
ms.WriteTo(fs);
// clean up
ms.Close();
fs.Close();
fs.Dispose();
new general().logError("After saving the file");
// return OK if we made it this far
return "OK";
}
catch (Exception ex)
{
return ex.Message.ToString();
}
}
The function that calls this WebMethod follows -
private void uploadIt(string fName)
{
FileStream f = File.OpenRead(fName);
cloudius.cloudius m = new cloudius.cloudius();
using (MemoryStream ms = new MemoryStream())
{
f.CopyTo(ms);
//string[] drive = fName.Split(':');
string[] p = fName.Split('\\');
string b = m.UploadFile(ms.ToArray(), p[p.Length - 1]); //
}
}
When running the aboce code I get the following error -
Client found response content type of 'text/html', but expected 'text/xml'.
Any idea what is causing this error ?
By the looks of things after some research, it looks like it is a form of a error page coming back. Go have a look here as well as here.
Hope this gives you some form of clarification on your problem.
Hey buddy if the main purpose of your method is just to upload a file you can use :
FileUpload fu; // Get the FileUpload object.
using (FileStream fs = File.OpenWrite("file.dat"))
{
fu.PostedFile.InputStream.CopyTo(fs);
fs.Flush();
}
That will be more efficient, as you will be directly streaming the input file to the destination host, without first caching in memory or on disk.
I working on a sharepoint project in which i have to upload the videos in the document library as videoset. after creating a video set i have have to upload the video and fetch the thumbnail from the video and upload it. video is uploaded succesfully using
spfile = item.Folder.Files.Add(fuUpload.FileName, fuUpload.PostedFile.InputStream, true);
I am using using Nreco to get thumbnail from the video. However my code works fine on local machine but its giving error "http://mysite/Download/abc/abc.mp4: Server returned 401 Unauthorized (authorization failed) (exit code: 1)" when i am using my application from other pc browsers.
ffMpeg.GetVideoThumbnail(videoPath, ms, 10); the error line.
here is the code i am using
private MemoryStream SaveThumbnail(string videoPath)
{
MemoryStream ms;
try
{
videoPath = "http://mysitehttp/Download/abc/abc.mp4"
ms = new MemoryStream();
SPSecurity.RunWithElevatedPrivileges(delegate() {
var ffMpeg = new NReco.VideoConverter.FFMpegConverter();
ffMpeg.GetVideoThumbnail(videoPath, ms, 10);
});
}
catch(Exception ex)
{
throw ex;
}
return ms;
}
Finally I have managed to solve this. For some reason SharePoint did not allow me to access the file directly from URL using NReco so i tweaked the function like this.
Instead of using file URL as argument i used the file object it self. and copied the stream on server temp folder in virtual directories then i used the file path on the system for NRreco to create the thumbnail. and in the end deleted the file from the server.
private MemoryStream SaveThumbnail(SPFile videoFile)
{
MemoryStream ms;
try
{
//Creating Temp File Path to be used by Nreco
ms = new MemoryStream();
SPSecurity.RunWithElevatedPrivileges(delegate() {
string destinationFile = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + videoFile.Name);
//Copying the content the content of the file at temp loaction from stream
using (FileStream fileStream = File.Create(destinationFile))
{
Stream lStream = videoFile.OpenBinaryStream();
byte[] contents = new byte[lStream.Length];
lStream.Read(contents, 0, (int)lStream.Length);
lStream.Close();
// Use write method to write to the file specified above
fileStream.Write(contents, 0, contents.Length);
fileStream.Close();
}
var ffMpeg = new NReco.VideoConverter.FFMpegConverter();
ffMpeg.GetVideoThumbnail(destinationFile, ms, 10);
System.IO.File.Delete(destinationFile);
});
}
catch(Exception ex)
{
throw ex;
}
return ms;
}
Someone might save some time from my answer. if anyone has a better solution let me know please.
I have a rich text editor that I have created in C#. One of the features I am now trying to add is templates. I do not want the user to have to use an OpenFileDialog to navigate to the template and open the file. I would like to specify the filepath myself so that the user only has to click one button in order to open the template.
Currently, I am trying to achieve this using the following code:
private void formalLetterToolStripMenuItem_Click(object sender, EventArgs e)
{
try
{
FileStream fileStream = new FileStream(#".\templates\tmp1.rtf", FileMode.Open);
String str;
str = fileStream.ToString();
string fileContents = File.ReadAllText(filepath);
fileContents = fileStream.ToString();
try
{
if (richTextBoxPrintCtrl1.Modified == true);
{
NewFile();
}
richTextBoxPrintCtrl1.Rtf = fileContents;
}
catch (Exception exception)
{
MessageBox.Show("There was an error opening the template. " + exception, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
catch (Exception exception)
{
MessageBox.Show("There was an error opening the template. " + exception, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
However, whenever I try to open the template, I get an exception that is as follows:
System.ArgumentsException: File format is not valid.
However, I have tried to open the file using my OpenFileDialog and that works fine. Could somebody assist me in getting this working correctly?
Your problem is that you're trying to convert the file to a string using str = fileStream.ToString(); however, this converts the filestream to a string which is not the same thing.
Instead just do string fileContents = File.ReadAllText(filepath); to get all of the files contents into a string. You only need to use a FileStream/StreamReader if you're going to do some type of processing on the file.
Also, your use of the FileStream is a little off. I think what you really want is a StreamReader with something like this (example from msdn);
using (StreamReader sr = new StreamReader("TestFile.txt"))
{
string line;
// Read and display lines from the file until the end of
// the file is reached.
while ((line = sr.ReadLine()) != null)
{
Console.WriteLine(line);
}
}
A FileStream cannot be used to read a file. It must be passed to a StreamReader in order to actually read the file and in this case there is no point in doing that because there is an overload of the constructor which takes a filepath. It's only useful if you don't know what kind of stream the reader is going to be reading.
Where you have;
FileStream fileStream = new FileStream(#".\templates\tmp1.rtf", FileMode.Open);
String str;
str = fileStream.ToString();
string fileContents = File.ReadAllText(filepath);
fileContents = fileStream.ToString();
You actually just want thins line; string fileContents = File.ReadAllText(filepath); , nothing else. There is no need for a FileStream when you're just reading all the text into a string.
You are making very heavy weather of loading RTF. Your code to read a file into a string will never work, as #evanmcdonnal explained. Did your file dialog based code that succeeded really do it like that? Remember that a file dialog is just UI that generates a file name in a string. If your code with a file dialog works, then it will work when the file dialog is replaced with a hard coded string.
I suspect that some part of your problem is that you are using a relative path. Perhaps the working directory is not what you expect it to be. You should specify the full path to the file.
In any case, to load RTF simply call the LoadFile method of the control. But I strongly recommend passing the full path to the file.
richTextBoxPrintCtrl1.LoadFile(fullPathToRtfFile);
I have written a procedure that will open a xls from a local disc, refresh the data in it and then save it again. This works fine.
The problem occurs when I replace the filename to point to a SharePoint site. It opens the file fine. Refreshes the file, but when it trys to save the file it throws an exception with the message "Cannot save as that name. Document was opened as read-only.".
If I try and save the file with a different filename then it works fine.
Does anybody know what I am missing? I think it must have somethoing to do with how I am opening the file. Is there another way that I can force the opening of the file in a read/write manner?
private static void RefreshExcelDocument(string filename)
{
var xls = new Microsoft.Office.Interop.Excel.Application();
xls.Visible = true;
xls.DisplayAlerts = false;
var workbook = xls.Workbooks.Open(Filename: filename, IgnoreReadOnlyRecommended: true, ReadOnly: false);
try
{
// Refresh the data from data connections
workbook.RefreshAll();
// Wait for the refresh occurs - *wish there was a better way than this.
System.Threading.Thread.Sleep(5000);
// Save the workbook back again
workbook.SaveAs(Filename: filename); // This is when the Exception is thrown
// Close the workbook
workbook.Close(SaveChanges: false);
}
catch (Exception ex)
{
//Exception message is "Cannot save as that name. Document was opened as read-only."
}
finally
{
xls.Application.Quit();
xls = null;
}
}
Many thanks in advance for suggestions.
Jonathan
Unfortunately you can't save directly to SharePoint using the Excel API. That's why the file is being opened as read only - it's not allowed.
The good news is that it is possible, but you have to submit the form via a web request. Even better news is that there is sample code on MSDN! In particular notice the PublishWorkbook method that sends a local copy of the Excel file to the server via a web request:
static void PublishWorkbook(string LocalPath, string SharePointPath)
{
WebResponse response = null;
try
{
// Create a PUT Web request to upload the file.
WebRequest request = WebRequest.Create(SharePointPath);
request.Credentials = CredentialCache.DefaultCredentials;
request.Method = "PUT";
// Allocate a 1K buffer to transfer the file contents.
// The buffer size can be adjusted as needed depending on
// the number and size of files being uploaded.
byte[] buffer = new byte[1024];
// Write the contents of the local file to the
// request stream.
using (Stream stream = request.GetRequestStream())
using (FileStream fsWorkbook = File.Open(LocalPath,
FileMode.Open, FileAccess.Read))
{
int i = fsWorkbook.Read(buffer, 0, buffer.Length);
while (i > 0)
{
stream.Write(buffer, 0, i);
i = fsWorkbook.Read(buffer, 0, buffer.Length);
}
}
// Make the PUT request.
response = request.GetResponse();
}
finally
{
response.Close();
}
}
The sample code describes a scenario for the 2007 versions of these products but other versions should behave in the same way.
What does the filename of a failed example looks like? Aren't documents used in SharePoint stored in the database? Or am I getting your problem wrong? Otherwise I could imagine that the file you are trying to store is write protected by the operation system and cannot be modified.