In my .net windows application am using a xml file .
But after installing the application by creating setup, while I am running that 'Access Denied' to that xml file message is shown.
I am using System.IO.File methods for doing file operations.
If any body knows the solution pls share.
Write access to program directory has been more and more restricted (starting with XP/Vista) since that is a secruity risk!
I would suggest to have the "base version" of that file readonly in your program directory...
Upon start of your app you check whether it is present in ApplicationData or LocalApplicationData or CommonApplicationData - (to get the real path at runtime use Environment.GetFolderPath). If it is not there then copy it there - in those locations your application has write access by default with no need for Administrator rights.
Program Files folder has limited access and can be modified by Administrator account. I would suggest you to save your xml file in *C:\Users\YourPCName\AppData\Local\YourAppFolder* .
This way you will be able to access and modify the file
I had this problem once so I used Isolated Storage and that fixed my problem. It may or may not work for you depending on the nature of your situation, but here's a quick tutorial on how to use it:
http://www.codeproject.com/KB/dotnet/IsolatedStorage.aspx
Related
Im trying to get the Users/Shared folder location in Mac so that i can write common user data(license) to it.I tried using
System.IO.Path.Combine (Environment.GetFolderPath (Environment.SpecialFolder.CommonApplicationData));
But its returning the folder in which I'm logged in.I know that i need to place the common application data in the Application Support folder but i think root privilege is required for this.If there is a better way to write to that folder,please suggest.
UPDATE:
I tried doing
File.Copy ("myfile.rtf", "Users//Shared//ll.txt");
But i get this exception >> Destination directory not found: Users/Shared
In OS X the directory is simply /Users/Shared, and it's directly off the root of the volume. There's no need to do Environment.GetFolderPath...
If you want to have user data or application data that can be shared by multiple users (read+write) you'll either want to create your own directory:
/Users/Shared/MyApp
and/or you can use:
/Users/Shared/Library/Application Support/MyApp
This way your application can share user data and application settings with all users. The /Library/Application Support folder (not to be confused with the one shared one), is owned by the system and anything that needs to write to it must obtain permission. The contents are read only, even for admin level users — something you'll want to consider when deciding where to store shared application data.
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!
I ran my program in C# that suppose to create and write a file in C:\, but an error occurred saying that access to the path C:\mytextfile.txt is denied. Is there any code that will give the user permission in C:\?
Yes by using the manifest http://www.codeproject.com/Articles/66259/Requesting-Admin-Approval-at-Application-Start or run as different account which has sufficient rights
You need to run the code as an administrator. You don't need C# code for this, you need to change how you're running the code.
However, I suspect that you're trying to do something wrong. I'd guess that you're trying to store some data locally, and are using the root of C: for simplicity, when you should actually be using the standard libraries to locate the users folder or to get a temporary file.
e.g. Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData)
(for other folders, use Intellisense to look at the other SpecialFolder children.)
I have a text file in Program Files. I cannot write it from a C# application while running in non-admin mode.
I am using this snippet
TextReader read = new StreamReader("C:\Program Files\......\link");
It is throwing an error that the access to the file is denied, however I can read it!
Thanks
Access to a file can be different for reading and writing. As a non-admin, it's normal to be able to read files in Program Files, but not be able to write them.
If the file is a setting for the current user, you should put it in a folder under the AppData folder. You can find the AppData folder's location by calling Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData))
If the file is a setting for all users on the computer, use Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData))
See http://msdn.microsoft.com/en-us/library/system.environment.specialfolder.aspx for a list of other possible special folder locations.
Non-admin users don't have write access to files in C:\Program Files by default. If you want to write to a file that is accessible to all users, you should create it in C:\ProgramData.
In .net there is a class File
through which you can use the method
File.read(file path)
this return a string
so you can easily manage it
it also works in a non admin mode
This snippet works well if I try to write in a user directory but as soon as I try to write in Program Files, it just executes silently and the file has not been copied (no exception). If I try to copy the file in C:\ or in C:\Windows I catch an UnauthorizedAccessException.
Do you know another way to get the permissions to write in that directory or to make it work another way?
Any help greatly appreciated! Thanks
using(FileStream fs=File.Open(source, FileMode.Open)){ }
try
{
FileIOPermission fp = new FileIOPermission(FileIOPermissionAccess.Write,
AccessControlActions.Change, "C:\\Program Files\\MyPath");
fp.Demand(); //<-- no exception but file is not copied
File.Copy("C:\\Users\\teebot\\Documents\\File.xml","C:\\Program Files\\MyPath\\File.xml",true);
}
catch(SecurityExceptions)
{
throw(s);
}
catch(UnauthorizedAccessException unauthroizedException)
{
throw unauthroizedException;
}
If you are running under Vista then the system just redirects writes to the program files folder, this is done so old program that keep their configuration in the program directory will continue to work when the user is not an Admin (or UAC is enabled).
All you have to do is add a manifest to your program that specify the required access level, then the system assume your program is Vista-aware and turns off all those compatibility patches.
You can see an example of a manifest file on my blog at:
http://www.nbdtech.com/blog/archive/2008/06/16/The-Application-Manifest-Needed-for-XP-and-Vista-Style-File.aspx
(the focus of the post is on getting the right version of the common controls, but the Vista security declarations are also there)
Don't write in the Program Files folder.
That's a big no-no, and will especially cause problems when the day comes where your code runs in Vista or on a machine at a company where users only get standard security rather than admin rights. Use the Application Data folder instead.
Are you running on Vista? If so then you may be running into file system virtualization. This is a feature in 32 bit versions of Vista which allows a normal user to write to protected parts of the file system. It's a shim introduced to reduce the pain of the LUA features of Vista.
The short version is that the operating system will create a virtual file system for certain protected roots (such as program files). When a non-admin attempts to write to it, a copy will be created an editted instead of the original. When your user account attempts to look at the file it will see the edit.s Other user accounts will only see the original.
Longer Version: http://thelazyadmin.com/blogs/thelazyadmin/archive/2007/04/26/file-system-virtualization.aspx
Code access security grants or denies permissions to your code.
It can't be used to override permissions that are granted/denied to the current user.