排序NSDates

Question

我在我的程序中有几个词典,我已将所有这些词典放在一个数组中我想对那些日期进行排序因此字典应该交换它的位置,下面显示的是我正在使用的代码,但我没有得到它排序.请帮助我解决这个问题

**NSLog(排序前的@" - %d",[allDataArray count]);

for(int i=0;i<[allDataArray count]-1;i++){
    NSString *dateStr1=[[allDataArray objectAtIndex:i]objectForKey:@"Date"];
    for(int j=i+1;j<[allDataArray count];j++){
        NSString *dateStr2=[[allDataArray objectAtIndex:j]objectForKey:@"Date"];
        if(([(NSDate*)dateStr1 compare:(NSDate*)dateStr2]==NSOrderedAscending)
           ||([(NSDate*)dateStr1 compare:(NSDate*)dateStr2]==NSOrderedSame))
            [allDataArray replaceObjectAtIndex:i withObject:[allDataArray objectAtIndex:j]];
    }
}
   NSLog(@"afterSorting-numbers--%@",allDataArray);**

Answer 1

看起来你在这里重新发明轮子(排序已经在几十年前解决了),而是这样做:

NSArray *allDataArray = ...;
NSArray *sortedAllDataArray = [allDataArray sortedArrayUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"Date" ascending:YES]]];

或这个:

NSArray *allDataArray = ...;
NSArray *sortedAllDataArray = [allDataArray sortedArrayUsingComparator:^NSComparisonResult(NSDictionary *dict1, NSDictionary *dict2) {
    return [[dict1 objectForKey:@"Date"] compare:[dict2 objectForKey:@"Date"]];
}]