CHandle: Difference between revisions

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[[Category:Variables]]
[[Category:Variables]]
[[Category:English]]

Revision as of 13:15, 14 May 2011

Template:Otherlang2

CHandle is a C++ class that represents a 32-bit ID (entindex + serial number) unique to every past and present entity in a game. It is used to refer to entities where pointers and entity indexes are unsafe; mainly across the client/server divide and after restoring a saved game.

Tip.pngTip:CHandles are slower to access than pointers. If you create pointers for access purposes and are supporting saved games, remember to repopulate them in Restore()!

Usage

CHandle<YourStoredClass> hMyHandle;

A CHandle is broadly similar to a pointer, but as it is a custom C++ class, and not a built-in feature, extra syntax is needed in some places:

  • You must assign a pointer to the object, not the object itself.
  • The CHandle's Get() function, or a cast, is required access the class it is storing.
  • IsValid() is used to check whether a value is stored.
  • To invalidate, call Term() or assign INVALID_EHANDLE_INDEX.

EHANDLE

CHandle is often used through the EHANDLE typedef, which is shorthand for CHandle<C_BaseEntity>. If you want to store a particular class it's better to declare a more specific CHandle manually (see previous section).

Example

// Create a pointer to an entity
CBasePlayer* pPlayer = gEntList.FindEntityByClassname( NULL, "player" );
 
// Store it (twice, for demonstration purposes)
EHANDLE hPlayer = pPlayer;
CHandle<CBasePlayer> hPlayer_ = pPlayer;
 
// Convert the EHANDLE back to a CBasePlayer pointer
pPlayer = dynamic_cast<CBasePlayer*>( hPlayer.Get() );

See Also