I have to read a text file which added in my project DataMid/Bigram_MidWord.txt where DataMid is a folder and Bigram_MidWord.txt is a file to read.
When i write the statement
FileStream fileStream = new FileStream(#"/SourceCode,component/DataMid/Bigram_MidWord.txt", FileMode.Open, FileAccess.ReadWrite);
then i get the exception as follows:
Attempt to access the method failed: System.IO.FileStream..ctor(System.String, System.IO.FileMode, System.IO.FileAccess)
How can I fix this issue?
The problem is that you are trying to use FileStream to access a resource that is embedded in your application's XAP file. FileStream is used for accessing the file system (e.g. isolated storage).
To access a text file that is a resource in your XAP file, you can use the following code:
string text;
Uri uri = new Uri("("/AssembyName;component/DataMid/Bigram_MidWord.txt", UriKind.RelativeOrAbsolute);
StreamResourceInfo sri = App.GetResourceStream(uri);
StreamReader sr = new StreamReader(sri.Stream);
text= sr.ReadToEnd();
sr.Close();
Related
I have a filename pointing to a text file, including its path, as a string. Now I'd like to load this .csv file into memory stream. How should I do that?
For example, I have this:
Dim filename as string="C:\Users\Desktop\abc.csv"
Dim stream As New MemoryStream(File.ReadAllBytes(filename))
You don't need to load a file into a MemoryStream.
You can simply call File.OpenRead to get a FileStream containing the file.
If you really want the file to be in a MemoryStream, you can call CopyTo to copy the FileStream to a MemoryStream.
I had an XML file being read from disk, using the old XmlReader API. How to read the XML file into memory, and then work with it in memory, instead of reading the disk repeatedly? Based on VB answer from Centro (upvoted) but with a Using block, and in C#.
The key line:
MemoryStream myXMLDocument = new MemoryStream(File.ReadAllBytes(#"c:\temp\myDemoXMLDocument.xml"));
Re the OP's question, if you wanted to load a CSV file into a MemoryStream:
MemoryStream myCSVDataInMemory = new MemoryStream(File.ReadAllBytes(#"C:\Users\Desktop\abc.csv"));
Following is a code snippet showing code to reads through XML document now that it's in a MemoryStream. Basically the same code as when it was coming from a FileStream that pointed to a file on disk. Yes, the XMLTextReader API is old and clunky, but it's what I had to work with in this app.
string myXMLFileName = #"c:\temp\myDemoXMLDocument.xml";
using (MemoryStream myXMLDocument = new MemoryStream(File.ReadAllBytes(myXMLFileName)))
{
myXMLTextReader = new XmlTextReader(myXMLDocument);
myXMLTextReader.WhitespaceHandling = WhitespaceHandling.None;
myXmlTextReader.Read(); // read the XML declaration node, advance to <Batch> tag
while (!myXmlTextReader.EOF)
{
if (myXmlTextReader.Name == "xml" && !myXmlTextReader.IsStartElement()) break;
// advance to <Batch> tag
while (myXmlTextReader.Name == "Batch" && myXmlTextReader.IsStartElement())
{
string BatchIdentifier = myXmlTextReader.GetAttribute("BatchIdentifier");
myXmlTextReader.Read(); // advance to next tag
while (!myXmlTextReader.EOF)
{
if (myXmlTextReader.Name == "Transaction" && myXmlTextReader.IsStartElement())
{
// Start a new set of items
string transactionID = myXmlTextReader.GetAttribute("ID");
myXmlTextReader.Read(); // Read next element, possibly another Transaction tag
}
}
//All Batch tags are completed.Move to next tag
myXmlTextReader.Read();
}
// Close the XML memory stream.
myXmlTextReader.Close();
myXmlDocument.Close();
}
}
You can copy it to a file stream like so:
string fullPath = Path.Combine(filePath, fileName);
FileStream fileStream = new FileStream(fullPath, FileMode.Open);
Image image = Image.FromStream(fileStream);
MemoryStream memoryStream = new MemoryStream();
image.Save(memoryStream, ImageFormat.Jpeg);
//Close File Stream
fileStream.Close();
I have few files in azure blobs that are stored with unique file names and when the client wants to download, i want to rename to a friendly name.
I'm still using 2014 azure storage dlls in my project and i'm not planning to update them anytime soon. So i can't use built-in ContentDeposition and rename it.
I tried using following code in my controller:
var blob = blobStorage.GetBlobRef("https://mysite.blob.core.windows.net/my-container/WERF3234435FFF_ERFas23E.doc");
MemoryStream memStream = new MemoryStream();
blob.DownloadToStream(memStream);
Response.ContentType = blob.Properties.ContentType;
Response.AddHeader("Content-Disposition", "Attachment; filename=abcd_New.doc");
Response.AddHeader("Content-Length", blob.Properties.Length.ToString());
Response.BinaryWrite(memStream.ToArray());
but its not downloading the file.
I also tried using this:
MemoryStream memStream = new MemoryStream();
blob.DownloadToStream(memStream);
System.Web.HttpContext.Current.Response.Clear();
System.Web.HttpContext.Current.Response.ContentType = blob.Properties.ContentType;
System.Web.HttpContext.Current.Response.AddHeader("Content-Disposition", "Attachment; filename=" + friendlyName.doc);
System.Web.HttpContext.Current.Response.AddHeader("Content-Length", blob.Properties.Length.ToString());
System.Web.HttpContext.Current.Response.BinaryWrite(memStream.ToArray());
System.Web.HttpContext.Current.Response.End();
I have my business logic in a separate solution and getting the blob reference from there to my main solution.
Am i missing something?
When we're talking about ASP.NET MVC, I'm missing the Controller/Action in your code? You're not supposed to write to the HttpContext yourself when doing ASP.NET MVC. You have ActionResults for that.
public ActionResult Download()
{
// ...
var bytes = memStream.ToArray();
return File(bytes, System.Net.Mime.MediaTypeNames.Application.Octet, "abcd_New.doc");
}
The browser will decide whether to open the file download or open it directly within the browser window. If you want to control that, you will need the following piece of code before you call the return File(... method:
var contentDisposition = new System.Net.Mime.ContentDisposition
{
FileName = "abcd_New.doc",
Inline = false // true will try to open in Browser, false will download
};
Response.AppendHeader("Content-Disposition", contentDisposition.ToString());
We need to flush our response after wrote a file to response. I use the code which you provided. After adding following code, I can see the file can be download from server.
Response.BinaryWrite(memStream.ToArray());
Response.Flush();
Response.End();
I have a mvc 4.5 application where I show a grid. The first column of the grid is a document name. The document name is an hyper link to the actual document that is hosted on our site and is available via a url. The documents can be pdf or doc or ppt. I can access these documents only via url and I do not have access to the actual physical document on our server.
I am providing users an option to select one or many of these documents from the grid and then they can download them. What I am trying to achieve is read each of the selected documents via the url and write it to a zip file and make the zip file downloadable. So users will be downloading one file instead of multiple files.
I have tried to stream the documents via url in memory and then add it to the zip file using ZipArchive Library from Microsoft. This is not working for me.
I was able to add documents that was on disk to zip file using Zip Archive and it works great. But I do not have access to the physical document as I can access the documents only through URL. My next option is to download each of these documents into a temp location on server and then add it to zip file using Zip Archive.But I am trying to avoid downloading files into a temp location
Please suggest how I can achieve reading documents via url in memory and adding each of these document to zip file and make zip file downloadable.
Any help will be appreciated.
Thank you Cbroe for commenting. I figured the answer. The problem was I was reading the pdf from the url and convert it to a memory stream and then was trying to add the memory stream to ZipArchive which was not working but instead I extracted the byte array out of the memory stream and then added it to the zip archive and it worked.
Here is the code snippet that might be useful for some one. My first contribution to Stack OverFlow.
public FileResult DownloadZip()
{
MemoryStream memoryStream = new MemoryStream();
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("Pdf123.pdf");
var convertedStream = ConvertTobyte("http://www.example.com/Pdf123.pdf");
using (var entryStream = demoFile.Open())
{
entryStream.Write(convertedStream, 0, convertedStream.Length);
}
demoFile = archive.CreateEntry("Pdf456.pdf");
convertedStream = ConvertTobyte("http://www.example.com/Pdf456.pdf");
using (var entryStream = demoFile.Open())
{
entryStream.Write(convertedStream, 0, convertedStream.Length);
}
}
//This option is to write the zip to your local disk
using (var fileStream = new FileStream(#"C:\Temp\test.zip", FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
//This option is to donload the zip via browser
memoryStream.Seek(0, SeekOrigin.Begin);
return new FileStreamResult(memoryStream, "application/zip")
{
FileDownloadName = "Archive.zip"
};
}
private static byte[] ConvertTobyte(string fileUrl)
{
byte[] imageData = null;
using (var wc = new System.Net.WebClient())
imageData = wc.DownloadData(fileUrl);
return imageData;
}
Is it possible to convert xlsx to Pdf like that?
FileStream sourceStream = new FileStream("C:\\Users\\Import.xlsx", FileMode.Open);
FileStream targetStream = new FileStream("C:\\Users\\Import.pdf", FileMode.CreateNew);
sourceStream.CopyTo(targetStream);
No, you are just copying the file to a new name. The actual content of the file will be exactly the same. No conversion is being performed.
I'm trying to return a stream in WCF 3.5 using a REST-Style URL instead of SOAP. The idea is to read a file from SharePoint 2010, then pass it back to the client. (We have reasons for doing it this way instead of using SharePoint services, but I digress.) It appears as though the only way to send the file is by writing it to the filesystem using one FileStream, then using File.OpenRead to return the stream back to the client. Using a MemoryStream doesn't seem to work. IE prompts for the file save, but the file comes down as like 2KB and then can't be read of course because it's not all there. Any ideas?
SPListItemCollection lookupFld2 = docLibrary.GetItems(spQuery2);
if (lookupFld2.Count > 0)
{
WebOperationContext.Current.OutgoingResponse.ContentType =
"application/octet-stream";
WebOperationContext.Current.OutgoingResponse.Headers.Add(
"Content-Disposition","attachment; filename=" + lookupFld2[0].File.Name);
MemoryStream memoryStream =
(MemoryStream)lookupFld2[0].File.OpenBinaryStream();
memoryStream.Position = 0;
return memoryStream;
}
Technically, OpenBinaryStream only returns a general Stream instance NOT a MemoryStream (http://msdn.microsoft.com/en-us/library/ms470901.aspx). If you want a MemoryStream you need to create a new one and copy the contents from the BinaryStream into the MemoryStream then reset the position and return it.