iphone - 使用 NSSortDescriptor 非常自定义的顺序

Question

假设我有不同状态的对象。状态从 0 到 2。我需要使用 NSSortDescriptor 以这种方式对它们进行排序:

1

2

0

有什么建议吗？

Answer 1

类似这样的东西(未经测试):

descriptor = [[[NSSortDescriptor alloc]
          initWithKey:@"status"
          ascending:YES
          selector:@selector(customStatusCompare:)] autorelease];

@interface NSNumber (CustomStatusCompare)
- (NSComparisonResult)customStatusCompare:(NSNumber*)other;
@end

@implementation NSNumber (CustomStatusCompare)
- (NSComparisonResult)customStatusCompare:(NSNumber*)other {
  NSAssert([other isKindOfClass:[NSNumber class]], @"Must be a number");
  if ([self isEqual:other]) {
    return NSOrderedSame;
  }
  else if (... all your custom comparison logic here ...)
  }
}