bionintl.blogg.se - Downcast to c

If pMyDoc does not point to an object derived directly or indirectly from CDocument, the macro will ASSERT. The class specified in the class_name parameter must be derived from CObject and must use the DECLARE_DYNAMIC and IMPLEMENT_DYNAMIC, the DECLARE_DYNCREATE and IMPLEMENT_DYNCREATE, or the DECLARE_SERIAL and IMPLEMENT_SERIAL macros as explained in the article CObject Class: Deriving a Class from CObject.įor example, you might cast a pointer to CMyDoc, called pMyDoc, to a pointer to CDocument using this expression: CDocument* pDoc = STATIC_DOWNCAST(CDocument, pMyDoc) In non- _DEBUG builds, the macro performs the cast without any type checking. In builds of your application with the _DEBUG preprocessor symbol defined, the macro will ASSERT if pobject is not NULL, or if it points to an object that is not a "kind of" the class specified in the class_name parameter (see CObject::IsKindOf). Pobject must either be NULL, or point to an object of a class which is derived directly, or indirectly, from class_name.

The pointer to be cast to a pointer to a class_name object. STATIC_DOWNCASTĬasts pobject to a pointer to a class_name object. If it is not a legal cast, the macro returns NULL. If the object referenced by the pointer is a "kind of" the identified class, the macro returns the appropriate pointer. The macro will cast the pointer parameter to a pointer to an object of the class parameter's type. DYNAMIC_DOWNCAST(class, pointer)Ī pointer to be cast to a pointer to an object of type class. Provides a handy way to cast a pointer to a pointer to a class object while checking to see if the cast is legal. In a debug build, causes an ASSERT if the object is not a "kind of" the target type. Macros That Cast Pointers to MFC Class Objects NameĬasts a pointer to a pointer to a class object while checking to see if the cast is legal.Ĭasts a pointer to an object from one class to a pointer of a related type. The following table lists the MFC type casting macros. When you tap Downcast in the list, you will be taken to an import view where you can select to import the file into a new "podcast" or add it to an existing one.Type casting macros provide a way to cast a given pointer to a pointer that points to an object of specific class, with or without checking that the cast is legal. Downcast will be included in this list if the file is an audio or video file. If the app supports it, when viewing a file it will display a "share" icon that, when tapped, will present a list of installed apps that can open the file in question.

"Open With" from another iOS App: Many iOS apps offer the ability to share files with other apps.

You can then choose to import any of them into a new "podcast" or select an existing one. After the items are extracted (which can take some time since some items may need to be converted to a supported file type), the items will show up in the import list. Choose the media items you'd like to extract and tap the "Done" button.

iOS Media Library: Navigate to the "More" view (tap the gear icon in the upper-right on the iPad), choose "Tools", "Import Media Files" and then tap "Extract from Media Library" in the bottom toolbar.

The file at the specified URL will be added to the selected podcast as a new episode and immediately queued for download.

Then paste or type the URL to the media file and tap the "Import" button.

URL: You can import a media file into Downcast via URL by navigating to the "Import" view (Tap the "More" tab (the gear icon in the upper-right on the iPad), choose "Tools" and finally, "Import Media Files") and selecting "URL" at the top of the screen.

You can then choose to import any of the synced media files into a new "podcast" or select an existing one. Then navigate to the "More" view (tap the gear icon in the upper-right if using an iPad), choose "Tools" and finally, "Import Media Files".

iTunes File Sharing: Using Apple's file sharing instructions you can sync media files to your iOS device.

There are three ways to import these files: The downcasting does not follow the is- a relation in most of the cases. It manually cast the base class’s object to the derived class’s object, so we must specify the explicit typecast. Downcast offers the ability to import audio and video files that may exist outside of any podcast feed. The Downcasting is an opposite process to the upcasting, which converts the base class’s pointer or reference to the derived class’s pointer or reference.