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InvalidCastException Class

The exception that is thrown for invalid casting or explicit conversion.

For a list of all members of this type, see InvalidCastException Members.


[Visual Basic]
Public Class InvalidCastException
   Inherits SystemException
public class InvalidCastException : SystemException
public __gc class InvalidCastException : public SystemException
class InvalidCastException extends SystemException

Thread Safety

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


InvalidCastException is thrown if:

  • For a conversion from a Single or a Double to a Decimal, the source value is infinity, Not-a-Number (NaN), or too large to be represented as the destination type.
  • A failure occurs during an explicit reference conversion.

For an explicit reference conversion to be successful, the source value must be a null reference (Nothing in Visual Basic), or the object type referenced by the source argument must be convertible to the destination type by an implicit reference conversion.

For information on conversions supported by the system, see the Convert class. For errors that occur when the destination type can store source type values, but is not large enough to store a specific source value, see OverflowException exception.

The following Microsoft intermediate language (MSIL) instructions throw InvalidCastException

  • castclass
  • refanyval
  • unbox

InvalidCastException uses the HRESULT COR_E_INVALIDCAST, which has the value 0x80004002.

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


Namespace: System

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework

Assembly: Mscorlib (in Mscorlib.dll)

See Also

InvalidCastException Members | System Namespace | Exception | Handling and Throwing Exceptions