Develop Reference

How to add existing file (image/mp4/pdf) to a ziparchive? - .Net Framework 4.6.2

I am trying to implement a "Download All" button that will zip up a selection of files from the server and return them as a zip file download. With the code below, I have the zip file being created. The expected files are inside, with the filenames expected, but the contents of the zipped files appears to be corrupted.
public ActionResult DownloadAll(Guid id)
{
var assets = db.InviteAssets.Include(i => i.AssetPages).Where(w => w.InviteID == id).ToList();
var cd = new System.Net.Mime.ContentDisposition
{
// for example foo.bak
FileName = "allAssets.zip",
// always prompt the user for downloading, set to true if you want
// the browser to try to show the file inline
Inline = false,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
foreach (var asset in assets)
{
string path, extension, name;
if (asset.AssetType != AssetType.PDF)
{
path = asset.AssetPages.First(f => f.PageNumber == 1).FilePath;
}
else
{
path = string.Format("/Content/Assets/asset_{0}.pdf", asset.ID);
}
extension = path.Substring(path.IndexOf('.'));
name = "asset" + asset.Order + extension;
var file = archive.CreateEntry(name);
using (var streamWriter = new StreamWriter(file.Open()))
{
using (var fileStream = System.IO.File.Open(Server.MapPath("~" + path), FileMode.Open))
{
int filelength = (int)fileStream.Length;
var filedata = new byte[fileStream.Length];
streamWriter.Write(fileStream.Read(filedata, 0, filelength));
}
}
}
}
return File(memoryStream.ToArray(), "application/json", "allAssets.zip");
}
}
I'm thinking my issue is therefore with this section:
using (var streamWriter = new StreamWriter(file.Open()))
{
using (var fileStream = System.IO.File.Open(Server.MapPath("~" + path), FileMode.Open))
{
int filelength = (int)fileStream.Length;
var filedata = new byte[fileStream.Length];
streamWriter.Write(fileStream.Read(filedata, 0, filelength));
}
}
I keep reading examples that use a method archive.CreateEntryFromFile(filePath, fileName) but no such method is recognised. Has this been deprecated, or requires a higher version of .Net Framework?
Thanks in advance.

The problem is here:
streamWriter.Write(fileStream.Read(filedata, 0, filelength));
You’re reading the file contents into filedata but you’re at the same time writing the return value of Read into the archive, meaning a single int. You need to read and write separately:
fileStream.Read(filedata, 0, filelength));
streamWriter.Write(filedata, 0, filelength);
Or you can use the CreateEntryFromFile extension method in System.IO.Compression.ZipFileExtensions namespace.

I discovered that the reason I couldn't see the CreateEntryFromFile method was because I had not included a reference to System.IO.Compression.FileSystem. Once I added that, I could use CreateEntryFromFile which worked fine.
So now I have: archive.CreateEntryFromFile(Server.MapPath("~" + path), name);
Instead of:
var file = archive.CreateEntry(name);
using (var streamWriter = new StreamWriter(file.Open()))
{
using (var fileStream = System.IO.File.Open(Server.MapPath("~" + path), FileMode.Open))
{
int filelength = (int)fileStream.Length;
var filedata = new byte[fileStream.Length];
fileStream.Read(filedata, 0, filelength);
streamWriter.Write(filedata);
}
}

Upload file chunks to SPS 2013 - Method "StartUpload" does not exist at line

I am trying to upload a large file (1 GB) from code to SharePoint 2013 on prem. I followed this tutorial, I dowloaded from NuGet the package "Microsoft.SharePointOnline.CSOM" and tried this piece of code:
public Microsoft.SharePoint.Client.File UploadFileSlicePerSlice(ClientContext ctx, string libraryName, string fileName, int fileChunkSizeInMB = 3)
{
// Each sliced upload requires a unique ID.
Guid uploadId = Guid.NewGuid();
// Get the name of the file.
string uniqueFileName = Path.GetFileName(fileName);
// Ensure that target library exists, and create it if it is missing.
if (!LibraryExists(ctx, ctx.Web, libraryName))
{
CreateLibrary(ctx, ctx.Web, libraryName);
}
// Get the folder to upload into.
List docs = ctx.Web.Lists.GetByTitle(libraryName);
ctx.Load(docs, l => l.RootFolder);
// Get the information about the folder that will hold the file.
ctx.Load(docs.RootFolder, f => f.ServerRelativeUrl);
ctx.ExecuteQuery();
// File object.
Microsoft.SharePoint.Client.File uploadFile;
// Calculate block size in bytes.
int blockSize = fileChunkSizeInMB * 1024 * 1024;
// Get the information about the folder that will hold the file.
ctx.Load(docs.RootFolder, f => f.ServerRelativeUrl);
ctx.ExecuteQuery();
// Get the size of the file.
long fileSize = new FileInfo(fileName).Length;
if (fileSize <= blockSize)
{
// Use regular approach.
using (FileStream fs = new FileStream(fileName, FileMode.Open))
{
FileCreationInformation fileInfo = new FileCreationInformation();
fileInfo.ContentStream = fs;
fileInfo.Url = uniqueFileName;
fileInfo.Overwrite = true;
uploadFile = docs.RootFolder.Files.Add(fileInfo);
ctx.Load(uploadFile);
ctx.ExecuteQuery();
// Return the file object for the uploaded file.
return uploadFile;
}
}
else
{
// Use large file upload approach.
ClientResult<long> bytesUploaded = null;
FileStream fs = null;
try
{
fs = System.IO.File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
using (BinaryReader br = new BinaryReader(fs))
{
byte[] buffer = new byte[blockSize];
Byte[] lastBuffer = null;
long fileoffset = 0;
long totalBytesRead = 0;
int bytesRead;
bool first = true;
bool last = false;
// Read data from file system in blocks.
while ((bytesRead = br.Read(buffer, 0, buffer.Length)) > 0)
{
totalBytesRead = totalBytesRead + bytesRead;
// You've reached the end of the file.
if (totalBytesRead == fileSize)
{
last = true;
// Copy to a new buffer that has the correct size.
lastBuffer = new byte[bytesRead];
Array.Copy(buffer, 0, lastBuffer, 0, bytesRead);
}
if (first)
{
using (MemoryStream contentStream = new MemoryStream())
{
// Add an empty file.
FileCreationInformation fileInfo = new FileCreationInformation();
fileInfo.ContentStream = contentStream;
fileInfo.Url = uniqueFileName;
fileInfo.Overwrite = true;
uploadFile = docs.RootFolder.Files.Add(fileInfo);
// Start upload by uploading the first slice.
using (MemoryStream s = new MemoryStream(buffer))
{
// Call the start upload method on the first slice.
bytesUploaded = uploadFile.StartUpload(uploadId, s);
ctx.ExecuteQuery();//<------here exception
// fileoffset is the pointer where the next slice will be added.
fileoffset = bytesUploaded.Value;
}
// You can only start the upload once.
first = false;
}
}
else
{
// Get a reference to your file.
uploadFile = ctx.Web.GetFileByServerRelativeUrl(docs.RootFolder.ServerRelativeUrl + System.IO.Path.AltDirectorySeparatorChar + uniqueFileName);
if (last)
{
// Is this the last slice of data?
using (MemoryStream s = new MemoryStream(lastBuffer))
{
// End sliced upload by calling FinishUpload.
uploadFile = uploadFile.FinishUpload(uploadId, fileoffset, s);
ctx.ExecuteQuery();
// Return the file object for the uploaded file.
return uploadFile;
}
}
else
{
using (MemoryStream s = new MemoryStream(buffer))
{
// Continue sliced upload.
bytesUploaded = uploadFile.ContinueUpload(uploadId, fileoffset, s);
ctx.ExecuteQuery();
// Update fileoffset for the next slice.
fileoffset = bytesUploaded.Value;
}
}
}
} // while ((bytesRead = br.Read(buffer, 0, buffer.Length)) > 0)
}
}
finally
{
if (fs != null)
{
fs.Dispose();
}
}
}
return null;
}
But I'm getting runtime exception : ServerExecution with the message: Method "StartUpload" does not exist at line "ctx.ExecuteQuery();" (<-- I marked this line in the code)
I also tried with SharePoint2013 package and the method "startupload" doesn't supported in this package.
UPDATE:
Adam's code worked for ~1GB files it turns out that inside web.config in the path : C:\inetpub\wwwroot\wss\VirtualDirectories\{myport}\web.config
at the part <requestLimit maxAllowedContentLength="2000000000"/> that's in bytes and not kilobytes as I thougt at the begining, therefore I changed to 2000000000 and it worked.

method to upload 1 GB file on SP 2013 using CSOM that works (tested and developed for couple of days of trying different approaches :) )
try
{
Console.WriteLine("start " + DateTime.Now.ToLongDateString() + " " + DateTime.Now.ToLongTimeString());
using (ClientContext context = new ClientContext("[URL]"))
{
context.Credentials = new NetworkCredential("[LOGIN]","[PASSWORD]","[DOMAIN]");
context.RequestTimeout = -1;
Web web = context.Web;
if (context.HasPendingRequest)
context.ExecuteQuery();
byte[] fileBytes;
using (var fs = new FileStream(#"D:\OneGB.rar", FileMode.Open, FileAccess.Read))
{
fileBytes = new byte[fs.Length];
int bytesRead = fs.Read(fileBytes, 0, fileBytes.Length);
}
using (var fileStream = new System.IO.MemoryStream(fileBytes))
{
Microsoft.SharePoint.Client.File.SaveBinaryDirect(context, "/Shared Documents/" + "OneGB.rar", fileStream, true);
}
}
Console.WriteLine("end " + DateTime.Now.ToLongDateString() + " " + DateTime.Now.ToLongTimeString());
}
catch (Exception ex)
{
Console.WriteLine("error -> " + ex.Message);
}
finally
{
Console.ReadLine();
}
Besides this I had to:
extend the max file upload on CA for this web application,
set on CA for this web application 'web page security Validation' on
Never (in this link there is a screen how to set it)
extend timeout on IIS
and the final result is:
sorry for the lang but I usually work in PL
all history defined here post

Install the SharePoint Online CSOM library using the command below.
Install-Package Microsoft.SharePointOnline.CSOM -Version 16.1.8924.1200
Then use the code below to upload the large file.
int blockSize = 8000000; // 8 MB
string fileName = "C:\\temp\\6GBTest.odt", uniqueFileName = String.Empty;
long fileSize;
Microsoft.SharePoint.Client.File uploadFile = null;
Guid uploadId = Guid.NewGuid();
using (ClientContext ctx = new ClientContext("siteUrl"))
{
ctx.Credentials = new SharePointOnlineCredentials("user#tenant.onmicrosoft.com", GetSecurePassword());
List docs = ctx.Web.Lists.GetByTitle("Documents");
ctx.Load(docs.RootFolder, p => p.ServerRelativeUrl);
// Use large file upload approach
ClientResult<long> bytesUploaded = null;
FileStream fs = null;
try
{
fs = System.IO.File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
fileSize = fs.Length;
uniqueFileName = System.IO.Path.GetFileName(fs.Name);
using (BinaryReader br = new BinaryReader(fs))
{
byte[] buffer = new byte[blockSize];
byte[] lastBuffer = null;
long fileoffset = 0;
long totalBytesRead = 0;
int bytesRead;
bool first = true;
bool last = false;
// Read data from filesystem in blocks
while ((bytesRead = br.Read(buffer, 0, buffer.Length)) > 0)
{
totalBytesRead = totalBytesRead + bytesRead;
// We've reached the end of the file
if (totalBytesRead <= fileSize)
{
last = true;
// Copy to a new buffer that has the correct size
lastBuffer = new byte[bytesRead];
Array.Copy(buffer, 0, lastBuffer, 0, bytesRead);
}
if (first)
{
using (MemoryStream contentStream = new MemoryStream())
{
// Add an empty file.
FileCreationInformation fileInfo = new FileCreationInformation();
fileInfo.ContentStream = contentStream;
fileInfo.Url = uniqueFileName;
fileInfo.Overwrite = true;
uploadFile = docs.RootFolder.Files.Add(fileInfo);
// Start upload by uploading the first slice.
using (MemoryStream s = new MemoryStream(buffer))
{
// Call the start upload method on the first slice
bytesUploaded = uploadFile.StartUpload(uploadId, s);
ctx.ExecuteQuery();
// fileoffset is the pointer where the next slice will be added
fileoffset = bytesUploaded.Value;
}
// we can only start the upload once
first = false;
}
}
else
{
// Get a reference to our file
uploadFile = ctx.Web.GetFileByServerRelativeUrl(docs.RootFolder.ServerRelativeUrl + System.IO.Path.AltDirectorySeparatorChar + uniqueFileName);
if (last)
{
// Is this the last slice of data?
using (MemoryStream s = new MemoryStream(lastBuffer))
{
// End sliced upload by calling FinishUpload
uploadFile = uploadFile.FinishUpload(uploadId, fileoffset, s);
ctx.ExecuteQuery();
// return the file object for the uploaded file
return uploadFile;
}
}
else
{
using (MemoryStream s = new MemoryStream(buffer))
{
// Continue sliced upload
bytesUploaded = uploadFile.ContinueUpload(uploadId, fileoffset, s);
ctx.ExecuteQuery();
// update fileoffset for the next slice
fileoffset = bytesUploaded.Value;
}
}
}
}
}
}
finally
{
if (fs != null)
{
fs.Dispose();
}
}
}
Or download the example code from GitHub.
Large file upload with CSOM

I'm looking for a way to upload 1GB file to SharePoint 2013
You can change the upload limit with the PowerShell below:
$a = [Microsoft.SharePoint.Administration.SPWebService]::ContentService
$a.ClientRequestServiceSettings.MaxReceivedMessageSize = 209715200
$a.Update()
References:
https://thuansoldier.net/4328/
https://blogs.msdn.microsoft.com/sridhara/2010/03/12/uploading-files-using-client-object-model-in-sharepoint-2010/
https://social.msdn.microsoft.com/Forums/en-US/09a41ba4-feda-4cf3-aa29-704cd92b9320/csom-microsoftsharepointclientserverexception-method-8220startupload8221-does-not-exist?forum=sharepointdevelopment
Update:
SharePoint CSOM request size is very limited, it cannot exceed a 2 MB limit and you cannot change this setting in Office 365 environment. If you have to upload bigger files you have to use REST API. Here is MSDN reference https://msdn.microsoft.com/en-us/library/office/dn292553.aspx
Also see:
https://gist.github.com/vgrem/10713514
File Upload to SharePoint 2013 using REST API
Ref: https://sharepoint.stackexchange.com/posts/149105/edit (see the 2nd answer).

Replicate Wave file using Naudio - Copy/Append Latest Available bytes

I have an Active wave recording wave-file.wav happening to the Source folder.
I need to replicate this file to Destination folder with a new name wave-file-copy.wav.
The recording and replication should happen in parallel.
I have implemented a scheduled job, which will run in every 10 minutes and copy the source file to destination.
private static void CopyWaveFile(string destinationFile, string sourceFile){
using (var fs = File.Open(sourceFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)){
using (var reader = new WaveFileReader(fs)){
using (var writer = new WaveFileWriter(destinationFile, reader.WaveFormat)){
reader.Position = 0;
var endPos = (int)reader.Length;
var buffer = new byte[1024];
while (reader.Position < endPos){
var bytesRequired = (int)(endPos - reader.Position);
if (bytesRequired <= 0) continue;
var bytesToRead = Math.Min(bytesRequired, buffer.Length);
var bytesRead = reader.Read(buffer, 0, bytesToRead);
if (bytesRead > 0){
writer.Write(buffer, 0, bytesRead);
}
}
}
}
}
}
The copy operation is working fine, even though the source file is being updated continuously.
Time taken for the copy operation is increasing in linear time, because i am copying the entire file every time.
I am trying to implement a new function ConcatenateWavFiles(), which should update the content of destination file, with the latest available bytes of source recording.
I have tried few sample codes - the approach i am using is :
Read destination file meta info, and get the length.
Set the length of destination file as reader.Position of source file waveReader
Read the source file till end, starting from position.
public static void ConcatenateWavFiles(string destinationFile, string sourceFile){
WaveFileWriter waveFileWriter = null;
var sourceReadOffset = GetWaveFileSize(destinationFile);
try{
using (var fs = File.Open(sourceFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
using (var reader = new WaveFileReader(fs))
{
waveFileWriter = new WaveFileWriter(destinationFile, reader.WaveFormat);
if (!reader.WaveFormat.Equals(waveFileWriter.WaveFormat)){
throw new InvalidOperationException(
"Can't append WAV Files that don't share the same format");
}
var startPos = sourceReadOffset - sourceReadOffset % reader.WaveFormat.BlockAlign;
var endPos = (int) reader.Length;
reader.Position = startPos;
var bytesRequired = (int)(endPos - reader.Position);
var buffer = new byte[bytesRequired];
if (bytesRequired > 0)
{
var bytesToRead = Math.Min(bytesRequired, buffer.Length);
var bytesRead = reader.Read(buffer, 0, bytesToRead);
if (bytesRead > 0)
{
waveFileWriter.Write(buffer, startPos, bytesRead);
}
}
}
}
}
finally{
if (waveFileWriter != null){
waveFileWriter.Dispose();
}
}
}
I was able to get the new content.
Is it possible to append the latest content to existing destination file?
If possible what am I doing wrong in the code?
My code throws the following exception - Offset and length were out of bounds for the array or count is greater than the number of elements from index to the end of the source collection.

I couldn't find a solution to wave audio file replication with NAudio Library.
But I have implemented a solution using C# MemoryStreams and FileStreams.
Copy the Source file to destination, if destination file doesn't exist.
Append all the latest bytes (recorded after the last operation) to the destination file.
Modify the Wave File Header to to reflect the last appended bytes. (Else the duration of the file will not be updated, only the file size will increase.
Repeat this append operation in regular intervals.
public void ReplicateFile(string destinationFile, string sourceFile){
if (!Directory.Exists(GetRoutePathFromFile(sourceFile)))
return;
if (!File.Exists(sourceFile))
return;
if (Directory.Exists(GetRoutePathFromFile(destinationFile))){
if (File.Exists(destinationFile)){
UpdateLatestWaveFileContent(destinationFile, sourceFile);
}else{
CopyWaveFile(destinationFile, sourceFile);
}
}else{
Directory.CreateDirectory(GetRoutePathFromFile(destinationFile));
CopyWaveFile(destinationFile, sourceFile);
}
}
private static string GetRoutePathFromFile(string file){
var rootPath = Directory.GetParent(file);
return rootPath.FullName;
}
private static void CopyWaveFile(string destination, string source){
var sourceMemoryStream = new MemoryStream();
using (var fs = File.Open(source, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)){
fs.CopyTo(sourceMemoryStream);
}
using (var fs = new FileStream(destination, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.ReadWrite)){
sourceMemoryStream.WriteTo(fs);
}
}
private static void UpdateLatestWaveFileContent(string destinationFile, string sourceFile){
var sourceMemoryStream = new MemoryStream();
long offset = 0;
using (var fs = File.Open(destinationFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)){
offset = fs.Length;
}
using (var fs = File.Open(sourceFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)){
fs.CopyTo(sourceMemoryStream);
}
var length = sourceMemoryStream.Length - offset;
var buffer = sourceMemoryStream.GetBuffer();
using (var fs = new FileStream(destinationFile, FileMode.Append, FileAccess.Write, FileShare.ReadWrite)){
fs.Write(buffer, (int)offset, (int)length);
}
var bytes = new byte[45];
for (var i = 0; i < 45; i++){
bytes[i] = buffer[i];
}
ModifyHeaderDataLength(destinationFile, 0, bytes);
}
private static void ModifyHeaderDataLength(string filename, int position, byte[] data){
using (Stream stream = File.Open(filename, FileMode.OpenOrCreate, FileAccess.Write, FileShare.ReadWrite))
{
stream.Position = position;
stream.Write(data, 0, data.Length);
}
}

Try Reading the Source File one or two Wav blocks prior to the actual end of the source file.
The case could be that the code is judging the end of the source file too close for comfort.

Looking for workaround due to FileStream.Create UnauthorizedAccessException

I am using FileStream.Create to upload a .csv file onto a server and then read it into a SQL database. Once it is read in, I just delete the file from the folder that it was written to. The goal is to just get the file into the database. This would run fine locally, but I cannot get write access on the new server so I get an UnauthorizedAccessException. I don't think that it is necessary to upload the file to the server to read it into the SQL table, but I am having trouble adjusting the code.
[HttpPost]
public ActionResult UploadValidationTable(HttpPostedFileBase csvFile)
{
var inputFileDescription = new CsvFileDescription
{
SeparatorChar = ',',
FirstLineHasColumnNames = true
};
var cc = new CsvContext();
var filePath = uploadFile(csvFile.InputStream);
var model = cc.Read<Credit>(filePath, inputFileDescription);
try
{
var entity = new Entities();
foreach (var item in model)
{
var tc = new TemporaryCsvUpload
{
Id = item.Id,
Amount = item.Amount,
Date = item.Date,
Number = item.Number,
ReasonId = item.ReasonId,
Notes = item.Notes
};
entity.TemporaryCsvUploads.Add(tc);
}
entity.SaveChanges();
System.IO.File.Delete(filePath);
Here is the uploadFile method:
private string uploadFile(Stream serverFileStream)
{
const string directory = "~/Content/CSVUploads";
var directoryExists = Directory.Exists(Server.MapPath(directory));
if (!directoryExists)
{
Directory.CreateDirectory(Server.MapPath(directory));
}
var targetFolder = Server.MapPath(directory);
var filename = Path.Combine(targetFolder, Guid.NewGuid() + ".csv");
try
{
const int length = 256;
var buffer = new byte[length];
// write the required bytes
using (var fs = new FileStream(filename, FileMode.Create))
{
int bytesRead;
do
{
bytesRead = serverFileStream.Read(buffer, 0, length);
fs.Write(buffer, 0, bytesRead);
} while (bytesRead == length);
}
serverFileStream.Dispose();
return filename;
}
catch (Exception)
{
return string.Empty;
}
}
To sum it up, I am uploading a .csv file to a temporary location, reading it into an object, reading it into a database, then deleting the .csv file out of the temporary location. I am using Linq2Csv to create the object. Can I do this without uploading the file to the server (because I can't get write access)?

According to http://www.codeproject.com/Articles/25133/LINQ-to-CSV-library,
you can read from a StreamReader
Read<T>(StreamReader stream)
Read<T>(StreamReader stream, CsvFileDescription fileDescription)
You can probably use a streamreader (or a stringbuilder) to create your file instead of a csv - Write StringBuilder to Stream
How to take a stringbuilder and convert it to a streamReader?
and then send that to your CSVContext?

How do I zip files in Xamarin for Android?

I have a function that creates a zip file a string array of files passed. The function does succeed in creating the zip file and the zip entry files inside it, but these zip entry files are empty. I've tried a couple of different methods - the function code below is the closest I've gotten to something working:
public static bool ZipFile(string[] arrFiles, string sZipToDirectory, string sZipFileName)
{
if (Directory.Exists(sZipToDirectory))
{
FileStream fNewZipFileStream;
ZipOutputStream zos;
try {
fNewZipFileStream = File.Create(sZipToDirectory + sZipFileName);
zos = new ZipOutputStream(fNewZipFileStream);
for (int i = 0; i < arrFiles.Length; i++) {
ZipEntry entry = new ZipEntry(arrFiles[i].Substring(arrFiles[i].LastIndexOf("/") + 1));
zos.PutNextEntry(entry);
FileStream fStream = File.OpenRead(arrFiles[i]);
BufferedStream bfStrm = new BufferedStream(fStream);
byte[] buffer = new byte[bfStrm.Length];
int count;
while ((count = bfStrm.Read(buffer, 0, 1024)) != -1) {
zos.Write(buffer);
}
bfStrm.Close();
fStream.Close();
zos.CloseEntry();
}
zos.Close();
fNewZipFileStream.Close();
return true;
}
catch (Exception ex)
{
string sErr = ex.Message;
return false;
}
finally
{
fNewZipFileStream = null;
zos = null;
}
}
else
{
return false;
}
}
I think it's got to do with the byte stream handling. I've tried this bit of code that handles the stream but it goes into an infinite loop:
while ((count = fStream.Read(buffer, 0, 1024)) != -1) {
zos.Write(buffer, 0, count);
}
fStream.Close();

I found a solution that is quite simple - I used the ReadAllBytes method of the static File class.
ZipEntry entry = new ZipEntry(arrFiles[i].Substring(arrFiles[i].LastIndexOf("/") + 1));
zos.PutNextEntry(entry);
byte[] fileContents = File.ReadAllBytes(arrFiles[i]);
zos.Write(fileContents);
zos.CloseEntry();

Using Read() on a FileStream returns the amount of bytes read into the stream or 0 if the end of the stream has been reached. It will never return a value of -1.
From MSDN:
The total number of bytes read into the buffer. This might be less than the number of bytes requested if that number of bytes are not currently available, orzero if the end of the stream is reached.
I'd modify your code to the following:
System.IO.FileStream fos = new System.IO.FileStream(sZipToDirectory + sZipFileName, FileMode.Create);
Java.Util.Zip.ZipOutputStream zos = new Java.Util.Zip.ZipOutputStream(fos);
byte[] buffer = new byte[1024];
for (int i = 0; i < arrFiles.Length; i++) {
FileInfo fi = new FileInfo (arrFiles[i]);
Java.IO.FileInputStream fis = new Java.IO.FileInputStream(fi.FullName);
ZipEntry entry = new ZipEntry(arrFiles[i].Substring(arrFiles[i].LastIndexOf("/") + 1));
zos.PutNextEntry(entry);
int count = 0;
while ((count = fis.Read(buffer)) > 0) {
zos.Write(buffer, 0, count);
}
fis.Close();
zos.CloseEntry();
}
This is nearly identical to the code I've used for creating zip archives on Android in the past.

Are you allowed to use SharpZip? It's really easy to use.
Here is a blog post I wrote to extract zip files
private static void upzip(string url)
{
WebClient wc = new WebClient();
wc.DownloadFile(url, "temp.zip");
//unzip
ZipFile zf = null;
try
{
zf = new ZipFile(File.OpenRead("temp.zip"));
foreach (ZipEntry zipEntry in zf)
{
string fileName = zipEntry.Name;
byte[] buffer = new byte[4096];
Stream zipStream = zf.GetInputStream(zipEntry);
using (FileStream streamWriter = File.Create( fileName))
{
StreamUtils.Copy(zipStream, streamWriter, buffer);
}
}
}
finally
{
if (zf != null)
{
zf.IsStreamOwner = true;
zf.Close();
}
}
}

private void ZipFolder(string[] _files, string zipFileName)
{
using var memoryStream = new MemoryStream();
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
foreach (var item in _files)
{
var demoFile = archive.CreateEntry(Path.GetFileName(item));
using var readStreamW = File.OpenRead(item);
using (var entryStream = demoFile.Open())
{
using (var streamWriter = new StreamWriter(entryStream))
{
readStreamW.Seek(0, SeekOrigin.Begin);
readStreamW.CopyTo(streamWriter.BaseStream);
}
}
}
}
using var fileStream = new FileStream(zipFileName, FileMode.Create);
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}