Why is access to the path denied?

问题:

I am having a problem where I am trying to delete my file but I get an exception.

if (result == \"Success\")
{
     if (FileUpload.HasFile)
     {
         try
         {
              File.Delete(Request.PhysicalApplicationPath + app_settings.login_images + txtUploadStatus.Text);
              string filename = Path.GetFileName(btnFileUpload.FileName);
              btnFileUpload.SaveAs(Request.PhysicalApplicationPath + app_settings.login_images + filename);
         }
         catch (Exception ex)
         {
               Message(ex.ToString());
         }
      }
}

Also I should note that the folder I am trying to delete from has full control to network services.

The full exception message is:

System.UnauthorizedAccessException: Access to the path \'C:\\Users\\gowdyn\\Documents\\Visual Studio 2008\\Projects\\hybrid\\hybrid\\temp_loginimages\\enviromental.jpg\' is denied. at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) at System.IO.File.Delete(String path) at hybrid.User_Controls.Imgloader_Add_Edit_Tbl.btnUpdate_Click(Object sender, EventArgs e) in C:\\Users\\gowdyn\\Documents\\Visual Studio 2008\\Projects\\hybrid\\hybrid\\User_Controls\\Imgloader_Add_Edit_Tbl.ascx.cs:line 242

Any ideas?

回答1:

I also had the problem, hence me stumbling on this post. I added the following line of code before and after a Copy / Delete.

Delete

File.SetAttributes(file, FileAttributes.Normal);
File.Delete(file);

Copy

File.Copy(file, dest, true);
File.SetAttributes(dest, FileAttributes.Normal);

回答2:

According to File.Delete Method...

An UnauthorizedAccessException means one of 4 things:

• The caller does not have the required permission.
• The file is an executable file that is in use.
• Path is a directory.
• Path specified a read-only file.

回答3:

This is an old issue, but I ran into it while searching. Turns out that I was missing the actual filename component in the save path for SaveAs...

string uploadPath = Server.MapPath(\"~/uploads\");
file.SaveAs(uploadPath); // BAD
file.SaveAs(Path.Combine(uploadPath, file.FileName)); // GOOD

回答4:

When a user tries to connect to your Web site, IIS assigns the connection to the IUSER_ComputerName account, where ComputerName is the name of the server on which IIS is running. By default, the IUSER_ComputerName account is a member of the Guests group. This group has security restrictions. Try to grand access to IUSER_ComputerName to that folder

Here is very good described answer about IIS security

Hope this helps

回答5:

Right click on Visual studio and click Run as Administrator

回答6:

If this is an IIS website that is having the problem, check the Identity property of the advanced settings for the application pool that the site or application uses. You may find that it is set to ApplicationPoolIdentity, and in that case then this is the user that will have to have access to the path.

Or you can go old style and simply set the Identity to Network Service, and give the Network Service user access to the path.

回答7:

I got the error because I didn\'t realize that the destination should be a file. I had a folder as the second parameter (which works in cmd). and I got Unhandled Exception: System.UnauthorizedAccessException: Access to the path is denied. because C# File.Move wants a file there, not just for the first parameter, but for the second too, and so if you put a directory as second parameter, it\'s trying to write a file like c:\\crp when you have a directory called c:\\crp.

this would be incorrect File.Move(args[0],\"c:\\\\crp\");

So, this would be correct File.Move(args[0],\"c:\\\\crp\\\\a.a\");

The same goes for File.Copy

回答8:

The exception that is thrown when the operating system denies access because of an I/O error or a specific type of security error.

I hit the same thing. Check to ensure that the file is NOT HIDDEN.

回答9:

I got this error and solved it in just a moment. Don\'t know why all of my folders are read-only，I cancelled the read-only and apply it. However, it is still read-only. So I moved the file into the root folder, it works - so weird.

回答10:

You need to modify the privileges of the folder you\'re trying to delete from/save to. Right-click on the containing folder and use the Security tab to permit modify rights for the user your application runs under.

回答11:

I had the same problem on a newly moved website on a shared server. Solved through the web host panel (DotNetPanel) setting true the \"allow write permissions\". So if you are in a shared server before reviewing all code worth taking a look at the server configuration and could save you a lot of time.

回答12:

Be aware that if you are trying to reach a shared folder path from your code, you dont only need to give the proper permissions to the physicial folder thru the security tab. You also need to \"share\" the folder with the corresponding app pool user thru the Share Tab

回答13:

Check your files properties. If the read-only is checked, uncheck it. This was my personal issue with the UnauthorizedAccessException.

回答14:

I was facing this error because

Sometimes when I Combine the path with File Name and FileName = \"\"

It become Path Directory not a file which is a problem as mentioned above

so you must check for FileName like this

if(itemUri!=\"\")
        File.Delete(Path.Combine(RemoteDirectoryPath, itemUri));

回答15:

An UnauthorizedAccessException exception is thrown when the operating system denies access because of an I/O error or a security error.

If you are attempting to access a file or registry key, make sure it is not read-only.

回答16:

I had the exact error when deleting a file. It was a Windows Service running under a Service Account which was unable to delete a .pdf document from a Shared Folder even though it had Full Control of the folder.

What worked for me was navigating to the Security tab of the Shared Folder > Advanced > Share > Add.

I then added the service account to the administrators group, applied the changes and the service account was then able to perform all operations on all files within that folder.

回答17:

I have also faced this issue when my window service started throwing the exception

System.UnauthorizedAccessException: Access to the path \"C:\\\\Order\\\\Media
44aa4857-3bac-4a18-a307-820450361662.mp4\" is denied.

So as a solution, I checked the user account associated with my service, as shown in below screen capture

So in my case it was NETWORK SERVICE

And then went to the folder properties to check if the associated user account also exists under their permission tab. It was missing in my case and when I added it and it fixed my issue.

For more information please check the below screen capture

回答18:

same issue for me too, I was pointing the folder instead of file.

so make sure in path, give path+filename

System.IO.File.WriteAllBytes(\"path\", bytearray);

回答19:

I too faced the same problem when trying to do this after deployment at server:

dirPath = Server.MapPath(\".\") + \"\\\\website\\\\\" + strUserName;
if (!Directory.Exists(dirPath))
{
    DirectoryInfo DI = Directory.CreateDirectory(dirPath);
}
string filePath = Server.MapPath(\".\") + \"\\\\Website\\\\default.aspx\";
File.Copy(filePath, dirPath + \"\\\\default.aspx\", true);
File.SetAttributes(dirPath + \"\\\\default.aspx\", FileAttributes.Normal);

I granted permission in IIS to other group including administrator and my problem got solved.

回答20:

I have found that this error can occur in DESIGN MODE as opposed to ? execution mode... If you are doing something such as creating a class member which requires access to an .INI or .HTM file (configuration file, help file) you might want to NOT initialize the item in the declaration, but initialize it later in FORM_Load() etc... When you DO initialize... Use a guard IF statement:

    /// <summary>FORM: BasicApp - Load</summary>
    private void BasicApp_Load(object sender, EventArgs e)
    {
        // Setup Main Form Caption with App Name and Config Control Info
        if (!DesignMode)
        {
            m_Globals = new Globals();
            Text = TGG.GetApplicationConfigInfo();
        }
    }

This will keep the MSVS Designer from trying to create an INI or HTM file when you are in design mode.

回答21:

I had this error thrown when I tried to rename a folder very rapidly after it had been either moved or created.

A simple System.Threading.Thread.Sleep(500); solved it:

void RenameFile(string from, string to)
{
   try
   {   
      System.IO.File.Move(from, to)      
   }   
   catch 
   {  
       System.Threading.Thread.Sleep(500);      
       RenameFile(from, to);      
   }   
}

回答22:

In my particular case I was repeatedly creating and deleting 10000 folders. It seems to me that the problem was in that although the method Directory.Delete(path, true) returns, the underling OS mechanism may still be deleting the files from the disk. And when I am starting to create new folders immediately after deletion of old ones, some of them are still locked because they are not completely deleted yet. And I am getting System.UnauthorizedAccessException: \"Access to the path is denied\".

Using Thread.Sleep(5000) after Directory.Delete(path, true) solves that problem. I absolutely agree that this is not safe, and I am not encouraging anyone to use it. I would love to here a better approach to solve this problem to improve my answer. Now I am just giving an idea why this exception may happen.

class Program
{
    private static int numFolders = 10000;
    private static string rootDirectory = \"C:\\\\1\";

    static void Main(string[] args)
    {
        if (Directory.Exists(rootDirectory))
        {
            Directory.Delete(rootDirectory, true);
            Thread.Sleep(5000);
        }

        Stopwatch sw = Stopwatch.StartNew();
        CreateFolder();
        long time = sw.ElapsedMilliseconds;

        Console.WriteLine(time);
        Console.ReadLine();
    }

    private static void CreateFolder()
    {
        var one = Directory.CreateDirectory(rootDirectory);

        for (int i = 1; i <= numFolders; i++)
        {
            one.CreateSubdirectory(i.ToString());
        }
    }
}

回答23:

First just check the path if the colon(:) character is missing or not after the drive letter. If colon is not missing then you can check if access/write permission is granted for that path. I had the same issue and i was only missing the colon, permission and everything else was fine.

C:\\folderpath

will work fine but,

C\\folderpath .........(missing colon)

will give you access denial error.