如何在 iPhone 中按降序对数组进行排序

本文介绍了如何在 iPhone 中按降序对数组进行排序的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试按降序对数组进行排序，我可以按升序对数组进行排序，这是我按升序排序的代码，

I am trying to sort an array in descending order,I can sort array in ascending order,Here is my code to sort in ascending order,

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"year" ascending:NO]; NSArray * descriptors = [NSArray arrayWithObjects:sortDescriptor, nil]; sortedArray = [array sortedArrayUsingDescriptors:descriptors]; dictionaryWithSortedYears = [[NSMutableDictionary alloc] init]; NSString *tempDateKey = nil; for (TreeXmlDetails *list in sortedArray) { id obj = [dictionaryWithSortedYears objectForKey:list.year]; if(!obj) { if(tempDateKey == nil) { arrayFromList = [[NSMutableArray alloc] init]; tempDateKey = list.year; } } if([list.year isEqualToString:tempDateKey]) [arrayFromList addObject:list]; else { [dictionaryWithSortedYears setObject:arrayFromList forKey:tempDateKey]; tempDateKey = nil; arrayFromList = nil; arrayFromList = [[NSMutableArray alloc] init]; tempDateKey = list.year; [arrayFromList addObject:list]; } } [dictionaryWithSortedYears setObject:arrayFromList forKey:tempDateKey]; NSArray *arr = [dictionaryWithSortedYears allKeys]; sortedKeys = [[NSArray alloc] initWithArray:[arr sortedArrayUsingSelector:@selector(compare:)]];

但是，我想按降序对数组进行排序，请帮帮我.提前致谢.

But, I want to sort an array in descending array,Please help me. Thanks in advnace.

推荐答案

使用以下内容:

[yourArrayToBeSorted sortUsingComparator:^NSComparisonResult(id obj1, id obj2){ return [(NSDate *)obj2 compare:(NSDate *)obj1];} ];