Attempts to acquire a lock, blocking a thread’s execution until the lock can be acquired. (required)
Original signature is '- (void)lock'
Available in Mac OS X v10.0 and later.

C# | Visual Basic | Visual C++ |
public virtual void Lock()
Public Overridable Sub Lock
public: virtual void Lock()

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)