GCHandle::Alloc Method (Object^)

.NET Framework (current version)

Allocates a Normal handle for the specified object.

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

Syntax

public:
[SecurityCriticalAttribute]
static GCHandle Alloc(
	Object^ value
)

Parameters

value: Type: System::Object^
The object that uses the GCHandle.

Return Value

Type: System.Runtime.InteropServices::GCHandle

A new GCHandle that protects the object from garbage collection. This GCHandle must be released with Free when it is no longer needed.

Exceptions

Exception	Condition
ArgumentException	An instance with nonprimitive (non-blittable) members cannot be pinned.

Remarks

Normal handles are opaque, which means that you cannot resolve the address of the object it contains through the handle.

The following example shows an App class that creates a handle to a managed object using the GCHandle.Alloc method, which prevents the managed object from being collected. A call to the EnumWindows method passes a delegate and a managed object (both declared as managed types, but not shown), and casts the handle to an IntPtr. The unmanaged function passes the type back to the caller as a parameter of the callback function.

C++

No code example is currently available or this language may not be supported.

Security

SecurityCriticalAttribute

requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

Version Information

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1