WDF_DECLARE_CONTEXT_TYPE マクロ

The WDF_DECLARE_CONTEXT_TYPE macro creates a name and an accessor method for a driver's object-specific context space.

構文

void WDF_DECLARE_CONTEXT_TYPE(
     _contexttype
);

パラメーター

• _contexttype
  The symbol name of a driver-defined structure. The structure must describe the contents of an object's context space.

戻り値

This マクロ は値を返しません。

解説

For more information about using this macro, see Framework Object Context Space.

例

The following code example defines a context structure (MY_REQUEST_CONTEXT) for a request object, registers the structure, and then invokes the WDF_DECLARE_CONTEXT_TYPE macro. The macro creates an accessor method for the context structure and names the method WdfObjectGet_MY_REQUEST_CONTEXT.

  typedef struct _MY_REQUEST_CONTEXT {
  LIST_ENTRY ListEntry;
  WDFMEMORY Memory;
} MY_REQUEST_CONTEXT, *PMY_REQUEST_CONTEXT;

WDF_DECLARE_CONTEXT_TYPE(MY_REQUEST_CONTEXT)

The following code example creates a request object, and then it uses the WdfObjectGet_MY_REQUEST_CONTEXT accessor method to obtain a pointer to the object's context space.

  WDFREQUEST Request;
WDF_OBJECT_ATTRIBUTES MyRequestObjectAttributes;
PMY_REQUEST_CONTEXT pMyContext;

WDF_OBJECT_ATTRIBUTES_INIT(&MyRequestObjectAttributes);
WDF_OBJECT_ATTRIBUTES_SET_CONTEXT_TYPE(
                                       &MyRequestObjectAttributes,
                                       MY_REQUEST_CONTEXT
                                       );
status = WdfRequestCreate(
                          &MyRequestObjectAttributes
                          NULL,
                          &Request
                          );
if (!NT_SUCCESS(status)) {
    return status;
}
pMyContext = WdfObjectGet_MY_REQUEST_CONTEXT(Request);

要件

参照

WdfObjectGetTypedContext

WDF_DECLARE_CONTEXT_TYPE_WITH_NAME