NullReferenceException Class
The exception that is thrown when there is an attempt to dereference a null object reference.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
The NullReferenceException type exposes the following members.
| Name | Description | |
|---|---|---|
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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. |
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NullReferenceException(String) | Initializes a new instance of the NullReferenceException class with a specified error message. |
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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. |
| Name | Description | |
|---|---|---|
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Data | Gets a collection of key/value pairs that provide additional user-defined information about the exception. (Inherited from Exception.) |
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HResult | Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception. (Inherited from Exception.) |
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InnerException | Gets the Exception instance that caused the current exception. (Inherited from Exception.) |
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Message | Gets a message that describes the current exception. (Inherited from Exception.) |
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StackTrace | Gets a string representation of the frames on the call stack at the time the current exception was thrown. (Inherited from Exception.) |
| Name | Description | |
|---|---|---|
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Equals(Object) | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) |
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Finalize | Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.) |
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GetBaseException | When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions. (Inherited from Exception.) |
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GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) |
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GetType | Gets the runtime type of the current instance. (Inherited from Exception.) |
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MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
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ToString | Creates and returns a string representation of the current exception. (Inherited from Exception.) |
Note that applications throw the ArgumentNullException exception rather than the NullReferenceException exception discussed here.
The following Microsoft intermediate language (MSIL) instructions throw NullReferenceException :
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callvirt
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cpblk
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cpobj
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initblk
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ldelem.<type>
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ldelema
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ldfld
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ldflda
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ldind.<type>
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ldlen
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stelem.<type>
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stfld
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stind.<type>
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throw
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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.
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.