UnauthorizedAccessException UnauthorizedAccessException UnauthorizedAccessException Class

Definition

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

public ref class UnauthorizedAccessException : SystemException
[System.Runtime.InteropServices.ComVisible(true)]
public class UnauthorizedAccessException : SystemException
Public Class UnauthorizedAccessException
Inherits SystemException
Inheritance
UnauthorizedAccessExceptionUnauthorizedAccessExceptionUnauthorizedAccessException
Derived
Attributes

Examples

The following example illustrates the UnauthorizedAccessException exception that is thrown when attempting to write to a read-only file.

using System;
using System.IO;

public class Example
{
   public static void Main()
   {
      string filePath = @".\ROFile.txt";
      if (! File.Exists(filePath))
         File.Create(filePath);
      // Keep existing attributes, and set ReadOnly attribute.
      File.SetAttributes(filePath, 
                        (new FileInfo(filePath)).Attributes | FileAttributes.ReadOnly);

      StreamWriter sw = null;
      try {
         sw = new StreamWriter(filePath);
         sw.Write("Test");
      }
      catch (UnauthorizedAccessException) {
         FileAttributes attr = (new FileInfo(filePath)).Attributes;
         Console.Write("UnAuthorizedAccessException: Unable to access file. ");
         if ((attr & FileAttributes.ReadOnly) > 0)
            Console.Write("The file is read-only."); 
       }
       finally {
         if (sw != null) sw.Close();
      }   
   }
}
// The example displays the following output:
//    UnAuthorizedAccessException: Unable to access file. The file is read-only.
Imports System.IO

Module Example
   Public Sub Main()
      Dim filePath As String = ".\ROFile.txt"
      If Not File.Exists(filePath) Then File.Create(filePath)
      ' Keep existing attributes, and set ReadOnly attribute.
      File.SetAttributes(filePath, 
                        (New FileInfo(filePath)).Attributes Or FileAttributes.ReadOnly)

      Dim sw As StreamWriter = Nothing
      Try
         sw = New StreamWriter(filePath)
         sw.Write("Test")
      Catch e As UnauthorizedAccessException
         Dim attr As FileAttributes = (New FileInfo(filePath)).Attributes
         Console.Write("UnAuthorizedAccessException: Unable to access file. ")
         If (attr And FileAttributes.ReadOnly) > 0 Then
            Console.Write("The file is read-only.") 
         End If
       Finally
         If sw IsNot Nothing Then sw.Close()
      End Try   
   End Sub
End Module
' The example displays the following output:
'   UnAuthorizedAccessException: Unable to access file. The file is read-only.

Remarks

An UnauthorizedAccessException exception is typically thrown by a method that wraps a Windows API call. To find the reasons for the exception, examine the text of the exception object's Message property.

UnauthorizedAccessException uses the HRESULT COR_E_UNAUTHORIZEDACCESS, which has the value 0x80070005.

Constructors

UnauthorizedAccessException() UnauthorizedAccessException() UnauthorizedAccessException()

Initializes a new instance of the UnauthorizedAccessException class.

UnauthorizedAccessException(SerializationInfo, StreamingContext) UnauthorizedAccessException(SerializationInfo, StreamingContext) UnauthorizedAccessException(SerializationInfo, StreamingContext)

Initializes a new instance of the UnauthorizedAccessException class with serialized data.

UnauthorizedAccessException(String) UnauthorizedAccessException(String) UnauthorizedAccessException(String)

Initializes a new instance of the UnauthorizedAccessException class with a specified error message.

UnauthorizedAccessException(String, Exception) UnauthorizedAccessException(String, Exception) UnauthorizedAccessException(String, Exception)

Initializes a new instance of the UnauthorizedAccessException class with a specified error message and a reference to the inner exception that is the cause of this exception.

Properties

Data Data Data

Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(Inherited from Exception)
HelpLink HelpLink HelpLink

Gets or sets a link to the help file associated with this exception.

(Inherited from Exception)
HResult HResult HResult

Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(Inherited from Exception)
InnerException InnerException InnerException

Gets the Exception instance that caused the current exception.

(Inherited from Exception)
Message Message Message

Gets a message that describes the current exception.

(Inherited from Exception)
Source Source Source

Gets or sets the name of the application or the object that causes the error.

(Inherited from Exception)
StackTrace StackTrace StackTrace

Gets a string representation of the immediate frames on the call stack.

(Inherited from Exception)
TargetSite TargetSite TargetSite

Gets the method that throws the current exception.

(Inherited from Exception)

Methods

Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetBaseException() GetBaseException() GetBaseException()

When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(Inherited from Exception)
GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetObjectData(SerializationInfo, StreamingContext) GetObjectData(SerializationInfo, StreamingContext) GetObjectData(SerializationInfo, StreamingContext)

When overridden in a derived class, sets the SerializationInfo with information about the exception.

(Inherited from Exception)
GetType() GetType() GetType()

Gets the runtime type of the current instance.

(Inherited from Exception)
MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString()

Creates and returns a string representation of the current exception.

(Inherited from Exception)

Events

SerializeObjectState SerializeObjectState SerializeObjectState

Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

(Inherited from Exception)

Applies to

See Also