C# 访问路径被拒绝在 Documents 中创建文件的异常

Question

I am trying to write a windows forms app that will write logs to a.txt file in:

Documents/subfolder/name.txt

I am able to create a the subfolder directory using

        string documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
        string dirPath = Path.Combine(documentsPath, appFolderName, logFolderSubpath);

        if (!Directory.Exists(dirPath))
        {
            Directory.CreateDirectory(dirPath);
        }

        string fileName = "log" + DateTime.Now.ToString("_yyyy-MM-dd_hh-mm-ss") + ".txt";

        string path = Path.Combine(dirPath, fileName);

but when I try to create a StreamWriter:

StreamWriter writer = new StreamWriter(Path.Combine(path, filename));

where filename is just a name of a.txt file, I get the exception:

System.UnauthorizedAccessException
  HResult=0x80070005
  Message=Access to the path 'C:\Users\milos_qhhen\Documents\DNDice\logs\log_2021-04-30_10-30-33.txt' is denied.
  Source=mscorlib
  StackTrace:
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.StreamWriter.CreateFile(String path, Boolean append, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path)
   at Character_Sheet.Logger..ctor() in D:\Milos\DND\Character Sheet\Character Sheet\Logger.cs:line 35
   at Character_Sheet.MainForm.MainForm_Load(Object sender, EventArgs e) in D:\Milos\DND\Character Sheet\Character Sheet\MainForm.cs:line 57
   at System.Windows.Forms.Form.OnLoad(EventArgs e)
   at System.Windows.Forms.Form.OnCreateControl()
   at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   at System.Windows.Forms.Control.CreateControl()
   at System.Windows.Forms.Control.WmShowWindow(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at System.Windows.Forms.Form.WmShowWindow(Message& m)
   at System.Windows.Forms.Form.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

  This exception was originally thrown at this call stack:
    [External Code]
    Character_Sheet.Logger.Logger() in Logger.cs
    Character_Sheet.MainForm.MainForm_Load(object, System.EventArgs) in MainForm.cs
    [External Code]

I am trying to make my app write log files into the Documents directory because this is a program that will be used by multiple people and I want a constant place where I can write the logs to. So I need my program to be able to create the directory, to create the file inside it, and then write into that file. I would prefer not to do this in the same directory where the.exe is.

Answer 1

Maybe the user you are using doesn't have write permission on that folder. Try to add write permission for you user or simply run the VS as administrator. It should work

Answer 2

I had this issue when running a .net console app on a Linux machine. the issues was that the user didn't have execute permissions to the folder

this command solved it for me

sudo chmod -R a+rwx ##folder path##