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NullReferenceException Class

.NET Framework 4.5

[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]

The exception that is thrown when there is an attempt to dereference a null object reference.

System.Object
  System.Exception
    System.SystemException
      System.NullReferenceException

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
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[SerializableAttribute]
[ComVisibleAttribute(true)]
public class NullReferenceException : SystemException

The NullReferenceException type exposes the following members.

  Name Description
Public method Supported by the XNA Framework Supported by Portable Class Library NullReferenceException() Initializes a new instance of the NullReferenceException class, setting the Message property of the new instance to a system-supplied message that describes the error, such as "The value 'null' was found where an instance of an object was required." This message takes into account the current system culture.
Public method Supported by the XNA Framework Supported by Portable Class Library NullReferenceException(String) Initializes a new instance of the NullReferenceException class with a specified error message.
Protected method NullReferenceException(SerializationInfo, StreamingContext) Initializes a new instance of the NullReferenceException class with serialized data.
Public method Supported by the XNA Framework Supported by Portable Class Library NullReferenceException(String, Exception) Initializes a new instance of the NullReferenceException class with a specified error message and a reference to the inner exception that is the cause of this exception.
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  Name Description
Public property Data Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception.)
Public property HelpLink Gets or sets a link to the help file associated with this exception. (Inherited from Exception.)
Public property Supported by the XNA Framework Supported by Portable Class Library HResult Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception.)
Public property Supported by the XNA Framework Supported by Portable Class Library InnerException Gets the Exception instance that caused the current exception. (Inherited from Exception.)
Public property Supported by the XNA Framework Supported by Portable Class Library Message Gets a message that describes the current exception. (Inherited from Exception.)
Public property Source Gets or sets the name of the application or the object that causes the error. (Inherited from Exception.)
Public property Supported by the XNA Framework Supported by Portable Class Library StackTrace Gets a string representation of the immediate frames on the call stack. (Inherited from Exception.)
Public property TargetSite Gets the method that throws the current exception. (Inherited from Exception.)
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  Name Description
Public method Supported by the XNA Framework Supported by Portable Class Library Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method Supported by the XNA Framework Supported by Portable Class Library Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method Supported by the XNA Framework Supported by Portable Class Library GetBaseException When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception.)
Public method Supported by the XNA Framework Supported by Portable Class Library GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetObjectData When overridden in a derived class, sets the SerializationInfo with information about the exception. (Inherited from Exception.)
Public method Supported by the XNA Framework Supported by Portable Class Library GetType Gets the runtime type of the current instance. (Inherited from Exception.)

In XNA Framework 3.0, this member is inherited from Object.GetType().

In Portable Class Library Portable Class Library, this member is inherited from Object.GetType().
Protected method Supported by the XNA Framework Supported by Portable Class Library MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method Supported by the XNA Framework Supported by Portable Class Library ToString Creates and returns a string representation of the current exception. (Inherited from Exception.)
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  Name Description
Protected event SerializeObjectState Occurs when an exception is serialized to create an exception state object that contains serialized data about the exception. (Inherited from Exception.)
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Note that applications throw the ArgumentNullException exception rather than the NullReferenceException exception discussed here.

The following Microsoft intermediate language (MSIL) instructions throw NullReferenceException :

  • callvirt

  • cpblk

  • cpobj

  • initblk

  • ldelem.<type>

  • ldelema

  • ldfld

  • ldflda

  • ldind.<type>

  • ldlen

  • stelem.<type>

  • stfld

  • stind.<type>

  • throw

  • unbox

NullReferenceException uses the HRESULT COR_E_NULLREFERENCE, which has the value 0x80004003.

For a list of initial property values for an instance of NullReferenceException, see the NullReferenceException constructors.

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 8 Consumer Preview, Windows Server 8 Beta, Windows 7, Windows Server 2008 SP2, Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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