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Namespace:

System.Runtime.InteropServices

Assemblies:

mscorlib.dll, System.Runtime.InteropServices.dll

Assemblies:

netstandard.dll, System.Runtime.InteropServices.dll

Assembly:

System.Runtime.InteropServices.dll

Assembly:

mscorlib.dll

Assembly:

netstandard.dll

Source:

Marshal.cs

Source:

Marshal.cs

Source:

Marshal.cs

Source:

Marshal.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

public: static int QueryInterface(IntPtr pUnk, Guid % iid, [Runtime::InteropServices::Out] IntPtr % ppv);

[System.Security.SecurityCritical]public static int QueryInterface(IntPtr pUnk, ref Guid iid, out IntPtr ppv);

public static int QueryInterface(IntPtr pUnk, in Guid iid, out IntPtr ppv);

[System.Runtime.Versioning.SupportedOSPlatform("windows")]public static int QueryInterface(IntPtr pUnk, ref Guid iid, out IntPtr ppv);

public static int QueryInterface(IntPtr pUnk, ref Guid iid, out IntPtr ppv);

[<System.Security.SecurityCritical>]static member QueryInterface : nativeint * Guid * nativeint -> int

static member QueryInterface : nativeint * Guid * nativeint -> int

[<System.Runtime.Versioning.SupportedOSPlatform("windows")>]static member QueryInterface : nativeint * Guid * nativeint -> int

Public Shared Function QueryInterface (pUnk As IntPtr, ByRef iid As Guid, ByRef ppv As IntPtr) As Integer

Parameters

Returns

An HRESULT that indicates the success or failure of the call.

Attributes

SecurityCriticalAttributeSupportedOSPlatformAttribute

Remarks

TheQueryInterface method exposes theIUnknown::QueryInterface method of a COM object, which attempts to obtain a specific interface pointer. UsingQueryInterface on a COM object is the same as performing a cast operation in managed code. Calling an object with this method causes the reference count to increment on the interface pointer before the pointer is returned. Always useMarshal.Release to decrement the reference count once you have finished with the pointer. To obtain anIntPtr value that represents aIUnknown interface pointer, you can callMarshal.GetComInterfaceForObject,Marshal.GetIUnknownForObject, orMarshal.GetIDispatchForObject.

See also

• AddRef(IntPtr)
• Release(IntPtr)
• GetComInterfaceForObject(Object, Type)
• GetIUnknownForObject(Object)
• GetIDispatchForObject(Object)
• GetObjectForIUnknown(IntPtr)