Develop Reference

System.UnauthorizedAccessException Why

Hi i have problem with permission(i think). Im trying to download a file from Mega.nz by MegaApiClient and when it trying to do that that problem appears:
"System.UnauthorizedAccessException: Access to the path '/storage/emulated/0/Download' is denied."
so i was trying different ways to do that like changing path folder or just simple create new file and write all content to that new file but nothing works.
of course i have permission added in AndroidManifest.xml
<uses-permission android:name="android.permission.WRITE_USER_DICTIONARY" />
<usespermissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
var client = new MegaApiClient();
client.LoginAnonymous();
Uri fileLink = new Uri(Link);
INodeInfo node = client.GetNodeFromLink(fileLink);
client.DownloadFile(node, node.Name); //problem occurs here
client.Logout();

I think that you are writing to internal memory not external.
On the new Android you need to make the user accept the permission. So there most be a warning popup to allow write permission, location, etc.
Also you may try this: Android Dev Console support

The problem probably occurs since your device / emulator on which you test your App has API 23 or higher. This means that the manifest permissions are not enough and you need to add runtime permissions asking for writing files.
This link will explain it using xamarin and this is the official documentation.
A runtime permission basically displays the user a dialog which lets him decide whether or not the App is allowed to access for instance the internal storage of the device.
Oh and this article will also help you implementing it.

C# The network path was not found

Im having trouble with writing files to remote directory via network. The following code fails when I try to check if the directory exists:
if (!Directory.Exists(processingPath))
Directory.CreateDirectory(processingPath);
processingPath is composed like
processingPath = xxxObject.serverPath + "processing\\";
xxxObject.serverPath contains something like this
\\machineNetworkName\sharedFolder\
Its working properly, but when many requests are processing (running as tasks asynchronously), it stops working and failing into exception:
System.IO.IOException: The network path was not found.
Could you please help me what could be the problem and why it is failing after some time on network path???
Thanks for your solutions

I got the same error before, it was about authentication problems.
You have to be sure that you set properly the user on IIS, because it use a Default App Pool's identity which can't access to your NFS.
You can also use IIS virtual folders to set the identity.
(on IIS manager, see App Pool settings -> Identity and also virtual folders settings -> identity).
In my case, it worked better by using the Impersonation directly in the code, so I recommend you to use the VladL WrappedImpersonationContext Object: How to provide user name and password when connecting to a network share
Last thing to check, the owner of the files on your NFS server, if they were created under the root user, it might not work.

I had the same problem and solved it. The problem in my code and I see it in yours, too, is that you have the slash at the end of the network path.
Instead of processingPath = xxxObject.serverPath + "processing\\"; write: processingPath = xxxObject.serverPath + "processing";

C# UWP using System.IO.Directory return empty array?

i am trying to return all the files contain in a folder in UWP application for Windows 10, the code is shown below:
var path = #"C:\Users\Desktop";
var files = System.IO.Directory.GetFiles(path); //get empty arrays
But, i get empty string arrays, may I know what causes this problem?

You can't. For uwp and store apps, only the app installation and app temp folders are granted for direct access. 'Direct' means ... accesses without Windows.Storge broker process. (System.IO is 'direct'.)
If you want to access the 'outside' of your app - like as desktop, you need to ask user to pick the location by File/FolderPicker. Without the user interaction, you can't access.
However, Windows.Storage broker service provide the rich methods for file operation, and additional functions like as CommnonQuery features.
There are some exception for pictures, video folders, but the basic concept is same.
Following link may helps you. :)
File access permissions

Probably because C:\Users\Desktop doesn't exist on the system - it would be under C:\Users\YOUR_USERNAME\Desktop.
Additionally, your application might be operating in a sandbox, so all filesystem access will be virtualized to a private silo elsewhere - Windows would pretend that the directory you specified exists but says it's empty, because it doesn't want you accessing the user's files without prior permission.

WP8 copy SharedStorge file directly into IsolatedStorage

I am developing a Windows Phone 8 application but am having a lot of issues with file access permission exceptions hindering the approval of my application when ever I try accessing files in the "local" folder (this only happens after the application has been signed by the WP store, not when deployed from Visual Studio). To solve this I have moved all file operations to IsolatedStorage and this seems to have fixed the problems.
I only have one problem left though. My application needs to make use of the file extension system to open external files and this seems to involve the file first being copied to the local folder where after I can then manually copy it into IsolatedStorage. I have no problem in implementing this but it seems that a file access permission exception also occurs once the system tries to copy the external file into the local folder.
The only way I think this can be solved is if I can direct the system to directly copy into IsolatedStorage but I cannot figure how to do this or if it is even possible. It seems as if though the SharedStorageAccessManager can only copy into a StorageFolder instance but I have no idea how to create one that is directed into IsolatedStorage, any ideas?
PS. Do you think that the Microsoft system might be signing my application with some incompetent certificate or something because there is not a hint of trouble when I deploy the application from Visual Studio, it only happens when Microsoft tests it or when I install it from the store using the Beta submission method.
Below is a screenshot of the catched exception being displayed in a messagebox upon trying to open a file from an email:
EDIT:
Just to make it even clearer, I do NOT need assistance in figuring out the normal practice of using a deep link uri to copy an external file into my application directory. I need help in either copying it directly into isolatedstorage or resolving the file access exception.

Listening for a file launch
When your app is launched to handle a particular file type, a deep link URI is used to take the user to your app. Within the URI, the FileTypeAssociation string designates that the source of the URI is a file association and the fileToken parameter contains the file token.
For example, the following code shows a deep link URI from a file association.
/FileTypeAssociation?fileToken=89819279-4fe0-4531-9f57-d633f0949a19
Upon launch, map the incoming deep link URI to an app page that can handle the file
// Get the file token from the URI
// (This is easiest done from a UriMapper that you implement based on UriMapperBase)
// ...
// Get the file name.
string incomingFileName = SharedStorageAccessManager.GetSharedFileName(fileID);
// You will then use the file name you got to copy it into your local folder with
// See: http://msdn.microsoft.com/en-us/library/windowsphone/develop/windows.phone.storage.sharedaccess.sharedstorageaccessmanager.copysharedfileasync(v=vs.105).aspx
SharedStorageAccessManager.CopySharedFileAsync(...)
I've inline the information on how to do this from MSDN http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj206987(v=vs.105).aspx
Read that documentation and it should be clear how to use the APIs as well as how to setup your URI mapper.
Good luck :)

Ok I figured it out. The "install" directory is actually restricted access but for some reason the Visual Studio signing process leaves the app with enough permissions to access this folder. The correct procedure of determining a relative directory is not to use "Directory.GetCurrentDirectory()" but rather to use "ApplicationData.Current.LocalFolder". Hope this helps!

Remote Upload Sharepoint programatically using C#

Is it possible to remotely upload files using a Windows Application (C#) to Sharepoint Server?
Thank you.

Yes, although you may need some of the SharePoint assemblies on the "remote" machine in order to achieve what you need.
Uploading files using Client Object Model in SharePoint 2010 is a pretty good starting point for SharePoint 2010.

In case you are using the 2007 version (WSS 3.0), you can find a great summary of different ways to upload files on this link: http://vspug.com/smc750/2009/05/19/uploading-content-into-sharepoint-let-me-count-the-ways/
You must be very careful if your farm is 32bit, in that case it is very easy to use up all the available memory in the w3wp.exe process if you're uploading large files or many files in parallel, especially if the farm is a busy one. In that case you might want to use the RPC interface described in the link above, since this is the only one where you can upload files in chunks. With all other ways the entire file being uploaded must first be loaded in the w3wp's memory before it's committed to the SharePoint list item.
For ways that involve SharePoint object model, you might want to write your own web service facade to enable the clients that do not have SharePoint dlls to upload files (+ metadata if you need it).

You can use the client object model in sp2010, rather than talking to the web services directly.
Taken from my upload profile picture applications:
http://spc3.codeplex.com/SourceControl/changeset/view/57957#1015709
using (ClientContext context = new ClientContext(siteurl)) {
context.AuthenticationMode = ClientAuthenticationMode.Default;
List list = context.Web.Lists.GetByTitle(listname);
context.Load(list);
context.Load(list.RootFolder);
context.ExecuteQuery();
string url = siteurl.CombineUrl(list.RootFolder.ServerRelativeUrl).CombineUrl(listfolder).CombineUrl(name);
FileCreationInformation fci = new FileCreationInformation();
fci.Content = data;
fci.Overwrite = true;
fci.Url = url;
Microsoft.SharePoint.Client.File file = list.RootFolder.Files.Add(fci);
context.ExecuteQuery();
}

I wrote a tool available as a NuGet package in Visual Studio called SharePoint.DesignFactory.ContentFiles. With this tool you can manage all files with metadata to be uploaded to the SharePoint content database. You can use this for SharePoint 2007 (currently have to work on the SharePoint machine itself) or for SharePoint 2010 and Office 365. In this case you can work from a machine without SharePoint installed. See http://weblogs.asp.net/soever/archive/tags/SharePoint.DesignFactory.ContentFiles/default.aspx for blogposts on the tooling.