I'm creating an UWP application to split CSV and Excel files. The user has to select a file in any folder on the machine and the application has to read the file. At the end of the process, the application has to save one or more files based on what the user wants.
When I try to read a CSV file with this code
using (var reader = new StreamReader(file))
using (var csv = new CsvReader(reader, config))
{
return csv.GetRecords<dynamic>();
}
I receive an error
System.UnauthorizedAccessException: 'Access to the path 'C:\Users\enric\Downloads\combined_data.csv' is denied.'
I checked the capabilities in the Package.appxmanifest but there is none related to files or folders. There is only Removable Storage that seems similar to what I'm looking for but it doesn't work.
In the Microsoft documentation, I read to add a custom capability
<Capabilities><uap:Capability Name="documentsLibrary"/></Capabilities>
but it doesn't work either.
You don't need to specify capabilities, just use pick file or read file code, this code can be also found in Microsoft doc and doc.
private async void Btn_OpenFile_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e)
{
try
{
FileOpenPicker picker = new FileOpenPicker();
picker.FileTypeFilter.Add(".csv");
picker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
var file = await picker.PickSingleFileAsync();
if (file != null)
{
}
}
catch
{
}
}
Related
I'm trying to add multiple files to an already created ZIP file using PickMultipleFilesAsync(). I previously created the ZIP file I want to access in the same code using FilesavePicker.PickSaveFileAsync() method. The app is running on Windows 10 Pro version 1803 in Laptop PC, and I used Visual Studio Community 2017 to create it.
The problem I get is that, after following steps described in the FileOpenPicker MSDN page, I get a System.UnauthorizedAccessException: 'Access to the path 'C:\Users\'User'\Downloads{ZIP file}' is denied.'
I created ZIP file and tried to add new files using this code:
StorageFile file = await savePicker.PickSaveFileAsync();
if (file != null)
{
// Prevent updates to the remote version of the file until we finish making changes and call CompleteUpdatesAsync.
CachedFileManager.DeferUpdates(file);
try
{
Stream stream = await file.OpenStreamForWriteAsync();
using (ZipArchive archive = new ZipArchive(stream, ZipArchiveMode.Update))
{
// This line works fine, file is added
archive.CreateEntryFromFile(path_to_another_file, file_name_in_ZIP);
//....
var dialog = new MessageDialog("Do you want to add more files to ZIP?");
//... (dialog configuration for Yes/No options)
var result = await dialog.ShowAsync();
if(result.Label == "Yes")
{
Debug.WriteLine("Yes option was selected!");
// Include additional files
var openPicker = new FileOpenPicker();
openPicker.FileTypeFilter.Add("*");
openPicker.SuggestedStartLocation = PickerLocationId.Downloads;
IReadOnlyList<StorageFile> addedFiles = await openPicker.PickMultipleFilesAsync();
if (addedFiles.Count > 0)
{
// Application now has read/write access to the picked file(s)
foreach (StorageFile addedFile in addedFiles)
{
Debug.WriteLine(addedFile.Path); // No problem here
// I get the UnauthorizedAccessException here:
archive.CreateEntryFromFile(addedFile.Path, #"additional files/" + addedFile.Name);
}
}
else
{
// Update log file
globalLog += GetTime() + "No additional files";
}
}
}
}
}
I already added <rescap:Capability Name="broadFileSystemAccess"/> to appxmanifest just in case, but as I had access to selected files using FileOpenPicker I think that is not the problem.
As I created the ZIP file within this code I should still have access to it, right? I suspect that FileOpenPicker somehow "closes" access to ZIP file in order to give access to files to be added, or that MessageDialog prevents of accessing the ZIP file I created after I called showAsync().
Is there any other way to achieve what I'm trying?
EDIT: I can not access the file(s) I select using FileOpenPicker, despite I can show file name(s) in Debug console. ZIP file access is OK.
I just found a solution. As stated here, you can use a buffer to stream file contents to ZIP file, just replace:
// I get the UnauthorizedAccessException here:
archive.CreateEntryFromFile(addedFile.Path, #"additional files/" + addedFile.Name);
With:
ZipArchiveEntry readmeEntry = archive.CreateEntry(#"additional files/" + addedFile.Name);
byte[] buffer = WindowsRuntimeBufferExtensions.ToArray(await FileIO.ReadBufferAsync(addedFile));
using (Stream entryStream = readmeEntry.Open())
{
await entryStream.WriteAsync(buffer, 0, buffer.Length);
}
That way, files are added and no UnauthorizedAccessException happens. Hope this helps anyone with the same problem!
I read some topic about file permission.
Someone said "App can access directories and files which the user manually selected with the FileOpenPicker or FolderPicker"
My codes are like as below:
public async void CsvParse()
{
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.FileTypeFilter.Add(".csv");
Windows.Storage.StorageFile file = await picker.PickSingleFileAsync();
if (file != null)
{
string[] lines = File.ReadAllLines(file.Path);//this is where app stops working and gives error message.
}
}
Even when I choose file with FilePicker, it still gives me error. But when I choose file from appx folder, it works fine.
Is there a way to access other locations than app's folder?
try it this way:
public async void CsvParse()
{
var picker = new Windows.Storage.Pickers.FileOpenPicker();
picker.FileTypeFilter.Add(".csv");
Windows.Storage.StorageFile file = await picker.PickSingleFileAsync();
if (file != null)
{
IList<string> lines = await FileIO.ReadLinesAsync(file);//this is where app stops working and gives error message.
}
}
the StorageFile is the way you get access to a file. File.ReadAllLines(file.Path) you are passing a Filename, not the StorageFile but just the filepath is not enough for getting access
I'm trying to create a file explorer for windows 10 mobile
I need to launch files with default app from pathes (not installed directory)
ex. "d:\test.pdf"
Here's what I've tried:
string p = #"a.jpg";
StorageFolder externalDevices = Windows.Storage.KnownFolders.RemovableDevices;
StorageFile file = await externalDevices.GetFileAsync(p);
var success = await Launcher.LaunchFileAsync(fff);
you can use Windows.System.Launcher API to launch the default handler for a file you can read more here
async void DefaultLaunch()
{
// Path to the file in the app package to launch
string imageFile = #"images\test.png";
var file = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(imageFile);
if (file != null)
{
// Launch the retrieved file
var success = await Windows.System.Launcher.LaunchFileAsync(file);
if (success)
{
// File launched
}
else
{
// File launch failed
}
}
else
{
// Could not find file
}
}
If you want to access files from SD card, please make sure that you have read the What you can and can't access on the SD card section on document.
Your app can only read and write files of file types that the app has registered to handle in the app manifest file.
Your app can also create and manage folders.
Make sure that you check "Removable Storage" in the capabilities of the appxmanifest.
You must declare a file type association in the Package.appxmanifest in order to read files from the SD card. The following is an example of one that I set up:
Then, I used the following code sample to launch a picture which is contained in "New folder" on SD card successfully.
string p = #"1.jpg";
StorageFolder externalDevices = Windows.Storage.KnownFolders.RemovableDevices;
var rootfolder = (await externalDevices.GetFoldersAsync()).FirstOrDefault();
var folder = await rootfolder.GetFolderAsync("New folder");
var file = await folder.GetFileAsync(p);
var success = await Launcher.LaunchFileAsync(file);
I'm trying to read data from json file in .NET 4.5 for Windows Phone app. After pressing button the exception appears saying:
System.IO.FileNotFoundException (Exception from HRESULT: 0x80070002)
My code:
public static async Task ReadFile()
{
StorageFolder local = Windows.ApplicationModel.Package.Current.InstalledLocation;
if (local != null)
{
var file = await local.OpenStreamForReadAsync("bazaDanych.json");
using (StreamReader streamReader = new StreamReader(file))
{
json = streamReader.ReadToEnd();
}
}
}
Here's my view of Solution Explorer:
You're not copying your file to the local storage.
Put your json file under the Assets folder, make sure that it's properties says "Content" and "Copy Always"
On the first launch you should read the json from the package
var filename = "Assets/BazaDanych.json";
var sFile = await StorageFile.GetFileFromPathAsync(filename);
var fileStream = await sFile.OpenStreamForReadAsync();
And store into the local storage.
There is an example for Windows 8 (which is more or less the same)
Related question.
I am facing a strange issue, I want to download a list of files from FTP. I preferred to go with Parallel Task. Below is my code. The issue is, all the list of files are getting downloaded, but duplicate files with different name are being generated. I am very new to Parallel task concept. Please help me to find out the issue.
Note: I am using SSH.Net for sftp connection and download.
private void ConcurrentDownload()
{
// Declaring Connection Information
PasswordAuthenticationMethod pm = new PasswordAuthenticationMethod("FTPUserName", "Password");
ConnectionInfo connectionInfo = new ConnectionInfo("FTPHost", 22, "FTPUserName", ProxyTypes.Socks5, "127.0.0.1", 8080, string.Empty, string.Empty, pm);
using (SftpClient sfc = new SftpClient(connectionInfo))
{
// Establish the remote connection
sfc.Connect();
// Getting Remote Directory Contents
IEnumerable<SftpFile> sFiles = new List<SftpFile>();
sFiles = sfc.ListDirectory(".\\");
// Building the File List
List<string> remotefiles = new List<string>();
foreach (SftpFile sfile in sFiles)
{
if (!sfile.IsDirectory)
{
string ss = sfile.Name;
remotefiles.Add(ss);
}
}
// Parallel Download
Parallel.ForEach(remotefiles.Distinct(), file => DownloadFile(sfc, file));
sfc.Disconnect();
}
}
private void DownloadFile(SftpClient sf, string RemoteFileName)
{
using (Stream ms = File.OpenWrite(RemoteFileName))
{
sf.DownloadFile(RemoteFileName, ms);
}
}
You better use Distinct like below
Parallel.ForEach(remotefiles.Distinct(), file => DownloadFile(sfc, file));
if you have duplicate file names and when parallel processing start on same file you will get exception on those duplicate files.
And also you are not downloading to another location, what you are doing is download to same ftp source location. is that correct?
I would give diferent download directory and get file name from source file and then download to that location as below
private void DownloadFile(SftpClient sf, string RemoteFileName)
{
string downloadTo = Path.Combine(DownloadDirectoryPath, Path.GetFileName(RemoteFileName));
using (Stream ms = File.OpenWrite(downloadTo))
{
sf.DownloadFile(RemoteFileName, ms);
}
}
Related Reference : SFTP Async Upload in Parallel