以下のようにする。iOSの場合とちょっと違うので注意。
- (id)init { NSNib *nib = [[NSNib alloc] initWithNibNamed:@"View" bundle:nil]; NSArray *topLevelObjects; if ([nib instantiateNibWithOwner:self topLevelObjects:&topLevelObjects]) { for (NSObject *object in topLevelObjects) { if ([object isMemberOfClass:[View class]]) { self = object; } } } return self; }
参考:objective c - programatically loading object from subclass of NSView from nib - Stack Overflow