UnauthorizedAccessException 类

定义

当操作系统因 I/O 错误或指定类型的安全错误而拒绝访问时所引发的异常。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)]
[System.Serializable]
public class UnauthorizedAccessException : SystemException
type UnauthorizedAccessException = class
    inherit SystemException
Public Class UnauthorizedAccessException
Inherits SystemException
继承
UnauthorizedAccessException
派生
属性

示例

下面的示例演示尝试UnauthorizedAccessException写入只读文件时引发的异常。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.

注解

通常情况下, 包装 Windows API 调用的方法会引发异常。UnauthorizedAccessExceptionAn UnauthorizedAccessException exception is typically thrown by a method that wraps a Windows API call. 若要查找异常的原因, 请检查异常对象Message的属性的文本。To find the reasons for the exception, examine the text of the exception object's Message property.

UnauthorizedAccessExceptionHRESULT 使用,COR_E_UNAUTHORIZEDACCESS其值为0x80070005。UnauthorizedAccessException uses the HRESULT COR_E_UNAUTHORIZEDACCESS, which has the value 0x80070005.

构造函数

UnauthorizedAccessException()

初始化 UnauthorizedAccessException 类的新实例。Initializes a new instance of the UnauthorizedAccessException class.

UnauthorizedAccessException(SerializationInfo, StreamingContext)

用序列化数据初始化 UnauthorizedAccessException 类的新实例。Initializes a new instance of the UnauthorizedAccessException class with serialized data.

UnauthorizedAccessException(String)

用指定的错误消息初始化 UnauthorizedAccessException 类的新实例。Initializes a new instance of the UnauthorizedAccessException class with a specified error message.

UnauthorizedAccessException(String, Exception)

使用指定的错误消息和对作为此异常原因的内部异常的引用来初始化 UnauthorizedAccessException 类的新实例。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.

属性

Data

获取提供有关异常的其他用户定义信息的键/值对集合。Gets a collection of key/value pairs that provide additional user-defined information about the exception.

(继承自 Exception)
HelpLink

获取或设置指向与此异常关联的帮助文件链接。Gets or sets a link to the help file associated with this exception.

(继承自 Exception)
HResult

获取或设置 HRESULT(一个分配给特定异常的编码数字值)。Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

(继承自 Exception)
InnerException

获取导致当前异常的 Exception 实例。Gets the Exception instance that caused the current exception.

(继承自 Exception)
Message

获取描述当前异常的消息。Gets a message that describes the current exception.

(继承自 Exception)
Source

获取或设置导致错误的应用程序或对象的名称。Gets or sets the name of the application or the object that causes the error.

(继承自 Exception)
StackTrace

获取调用堆栈上的即时框架字符串表示形式。Gets a string representation of the immediate frames on the call stack.

(继承自 Exception)
TargetSite

获取引发当前异常的方法。Gets the method that throws the current exception.

(继承自 Exception)

方法

Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetBaseException()

当在派生类中重写时,返回 Exception,它是一个或多个并发的异常的根源。When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

(继承自 Exception)
GetHashCode()

作为默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetObjectData(SerializationInfo, StreamingContext)

当在派生类中重写时,用关于异常的信息设置 SerializationInfoWhen overridden in a derived class, sets the SerializationInfo with information about the exception.

(继承自 Exception)
GetType()

获取当前实例的运行时类型。Gets the runtime type of the current instance.

(继承自 Exception)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

创建并返回当前异常的字符串表示形式。Creates and returns a string representation of the current exception.

(继承自 Exception)

事件

SerializeObjectState

当异常被序列化用来创建包含有关该异常的徐列出数据的异常状态对象时会出现该问题。Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception.

(继承自 Exception)

适用于

另请参阅