How to check file permission to write in c#

If you need to check that sufficient permissions exist to write to file or not.The following code example shows the use of the FileIOPermission(FileIOPermissionAccess, String) constructor to create a new instance of the FileIOPermission class with the write access to the C:\test.txt file, Write access includes deleting and overwriting files or directories. And then we can determine whether a write permission is granted or not with the help of SecurityManager.IsGranted() method.
 

//First method:
 
string FileLocation = @"C:\test.txt";
FileIOPermission writePermission = new FileIOPermission(
     FileIOPermissionAccess.Write, FileLocation);
if (SecurityManager.IsGranted(writePermission))
    {
  // you have permission
    }
else
    {
 // permission is required!
    }

 
The simplest way is try to access the directory and catch the UnauthorizedAccessException; if the exception was thrown the user does not have access.

 // Second method
try
     {
       // Write the code to check access file or directory
     }
catch (UnauthorizedAccessException ex)
     {
        MessageBox.Show("permission is required!");
     }
catch (Exception ex1)
     {
         MessageBox.Show(ex1.Message);
     }

Author: Hirendra Sisodiya

Programmer at PSPL. Can be found on Google Plus.