NSArray的排序功能sortedArrayUsingSelector

 

- (NSArray *)sortedArrayUsingSelector:(SEL)comparator

Parameters

comparator

A selector that identifies the method to use to compare two elements at a time. The method should returnNSOrderedAscending if the receiver is smaller than the argument, NSOrderedDescending if the receiver is larger than the argument, and NSOrderedSame if they are equal

 

NSArray *sortedArray =

    [anArray sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];

 

 

 

@property (nonatomic,readwrite, retain) NSMutableArray *parameters;

 

[self.parameterssortUsingSelector:@selector(compare:)];

 

 

#pragma mark -

 

- (NSComparisonResult)compare:(id)inObject {

NSComparisonResult result = [self.namecompare:[(MPURLRequestParameter *)inObjectname]];

 

if (result ==NSOrderedSame) {

result = [self.valuecompare:[(MPURLRequestParameter *)inObjectvalue]];

}

 

return result;

}

 

//////////////////////////////////////////////////////////

 

sortedArrayUsingFunction:适合基本类型（支持compare方法）

#pragma mark SORT METHOTDS

NSInteger sortObjectsByLatestTime(id obj1,id obj2, void *context)

{

 

NSDate* d1 = [(MessageGroup*)obj1latestTime];

NSDate* d2 = [(MessageGroup*)obj2latestTime];

 

//sort by desc

return [d2compare:d1];

}

 

NSInteger dateSort(id obj1,id obj2, void *context)

{

NSDate* d1 = ((Inbox*)obj1).datetime;

NSDate* d2 = ((Inbox*)obj2).datetime;

 

 

return [d1compare:d2];

}

////////////////////////////////////////////////////////////////////

 

 

-(NSArray*)sortedMessages

{

return [[groupMessagesallValues] sortedArrayUsingFunction:sortObjectsByLatestTimecontext:NULL];

}

//////////////////////////////////////////////////////////

sortUsingDescriptors:适合元素是dict类型，initWithKey既是dict key.

 

NSMutableArray *regions = [NSMutableArrayarray];

 

 

NSSortDescriptor *sortDescriptor = [[NSSortDescriptoralloc] initWithKey:@"name"ascending:YES];

NSArray *sortDescriptors = [NSArrayarrayWithObject:sortDescriptor];

[regionssortUsingDescriptors:sortDescriptors];

[sortDescriptor release];