iOS … NS_REQUIRES_NIL_TERMINATION – iPhone手機開發技術文章 iPhone軟體開發教學課程

看到官方的一個例子不錯,這裡留記。

 

#import 

@interface NSMutableArray (variadicMethodExample)

- (void) appendObjects:(id) firstObject, ...; // This method takes a nil-terminated list of objects.

@end

@implementation NSMutableArray (variadicMethodExample)

- (void) appendObjects:(id) firstObject, ...
{
id eachObject;
va_list argumentList;
if (firstObject) // The first argument isn't part of the varargs list,
  {                                   // so we'll handle it separately.
  [self addObject: firstObject];
  va_start(argumentList, firstObject); // Start scanning for arguments after firstObject.
  while (eachObject = va_arg(argumentList, id)) // As many times as we can get an argument of type id
      [self addObject: eachObject]; // that isn't nil, add it to self's contents.
  va_end(argumentList);
  }
}

@end 

 

最經常見到的應該是UIAlertView裡用的瞭。

 

- (id)initWithTitle:(NSString *)title message:(NSString *)message delegate:(id /**/)delegate cancelButtonTitle:(NSString *)cancelButtonTitle otherButtonTitles:(NSString *)otherButtonTitles, ... NS_REQUIRES_NIL_TERMINATION;

 

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