AccessViolationException Class
The exception that is thrown when there is an attempt to read or write protected memory.
Assembly: mscorlib (in mscorlib.dll)
The AccessViolationException type exposes the following members.
| Name | Description | |
|---|---|---|
| AccessViolationException() | Initializes a new instance of the AccessViolationException class with a system-supplied message that describes the error. | |
| AccessViolationException(String) | Initializes a new instance of the AccessViolationException class with a specified message that describes the error. | |
| AccessViolationException(SerializationInfo, StreamingContext) | Initializes a new instance of the AccessViolationException class with serialized data. | |
| AccessViolationException(String, Exception) | Initializes a new instance of the AccessViolationException class with a specified error message and a reference to the inner exception that is the cause of this exception. |
| Name | Description | |
|---|---|---|
| Data | Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception.) | |
| HelpLink | Gets or sets a link to the help file associated with this exception. (Inherited from Exception.) | |
| HResult | Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception.) | |
| InnerException | Gets the Exception instance that caused the current exception. (Inherited from Exception.) | |
| Message | Gets a message that describes the current exception. (Inherited from Exception.) | |
| Source | Gets or sets the name of the application or the object that causes the error. (Inherited from Exception.) | |
| StackTrace | Gets a string representation of the immediate frames on the call stack. (Inherited from Exception.) | |
| TargetSite | Gets the method that throws the current exception. (Inherited from Exception.) |
| Name | Description | |
|---|---|---|
| Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) | |
| Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) | |
| 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 | Serves as a hash function for a particular type. (Inherited from Object.) | |
| GetObjectData | When overridden in a derived class, sets the SerializationInfo with information about the exception. (Inherited from Exception.) | |
| GetType | Gets the runtime type of the current instance. (Inherited from Exception.) | |
| MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) | |
| ToString | Creates and returns a string representation of the current exception. (Inherited from Exception.) |
| Name | Description | |
|---|---|---|
| SerializeObjectState | Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception.) |
An access violation occurs in unmanaged or unsafe code when the code attempts to read or write to memory that has not been allocated, or to which it does not have access. This usually occurs because a pointer has a bad value. Not all reads or writes through bad pointers lead to access violations, so an access violation usually indicates that several reads or writes have occurred through bad pointers, and that memory might be corrupted. Thus, access violations almost always indicate serious programming errors. In the .NET Framework version 2.0, an AccessViolationException clearly identifies these serious errors.
In programs consisting entirely of verifiable managed code, all references are either valid or null, and access violations are impossible. An AccessViolationException occurs only when verifiable managed code interacts with unmanaged code or with unsafe managed code.
Version Information
This exception is new in the .NET Framework version 2.0. In earlier versions of the .NET Framework, an access violation in unmanaged code or unsafe managed code is represented by a NullReferenceException in managed code. A NullReferenceException is also thrown when a null reference is dereferenced in verifiable managed code, an occurrence that does not involve data corruption, and there is no way to distinguish between the two situations in versions 1.0 or 1.1.
Administrators can allow selected applications to revert to the behavior of the .NET Framework version 1.1. Place the following line in the <runtime> Element section of the configuration file for the application:
<legacyNullReferenceExceptionPolicy enabled = "1"/>
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.