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11/18/2011

SafeHandle Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

This type can be used only by trusted applications. If you try to use its members in a partial-trust application, your code will throw a MethodAccessException exception. This type is security-critical, which restricts its use.

[SECURITY CRITICAL]

Represents a wrapper class for operating system handles. This class must be inherited.

Inheritance Hierarchy

System.Object
System.Runtime.ConstrainedExecution.CriticalFinalizerObject
System.Runtime.InteropServices.SafeHandle

Namespace: System.Runtime.InteropServices
Assembly: mscorlib (in mscorlib.dll)

Syntax

'Declaration
<SecurityCriticalAttribute> _
Public MustInherit Class SafeHandle _
    Inherits CriticalFinalizerObject _
    Implements IDisposable

[SecurityCriticalAttribute]
public abstract class SafeHandle : CriticalFinalizerObject, 
    IDisposable

The SafeHandle type exposes the following members.

Constructors

	Name	Description
	SafeHandle()	Initializes a new instance of the SafeHandle class using system defaults.
	SafeHandle(IntPtr, Boolean)	Initializes a new instance of the SafeHandle class with the specified invalid handle value.

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Properties

	Name	Description
	IsClosed	Gets a value indicating whether the handle is closed.
	IsInvalid	When overridden in a derived class, gets a value indicating whether the handle value is invalid.

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Methods

	Name	Description
	Close	Security Critical. Marks the handle for releasing and freeing resources.
	DangerousAddRef	Security Critical. Manually increments the reference counter on SafeHandle instances.
	DangerousGetHandle	Returns the value of the handle field.
	DangerousRelease	Security Critical. Manually decrements the reference counter on a SafeHandle instance.
	Dispose()	Releases all resources used by the SafeHandle class.
	Dispose(Boolean)	Security Critical. Releases the unmanaged resources used by the SafeHandle class specifying whether to perform a normal dispose operation.
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Frees all resources associated with the handle. (Overrides CriticalFinalizerObject.Finalize().)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ReleaseHandle	When overridden in a derived class, executes the code required to free the handle.
	SetHandle	Sets the handle to the specified pre-existing handle.
	SetHandleAsInvalid	Security Critical. Marks a handle as no longer used.
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Fields

	Name	Description
	handle	Specifies the handle to be wrapped.

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Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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.

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