iphone - 排序NSDate

Question

我的程序中有几个字典，我将所有这些字典放入一个数组中，我想对这些日期进行排序，字典应该交换其位置，下面显示的是我正在使用的代码，但我没有对它进行排序。请帮助解决这个问题

** NSLog(@“在排序之前-％d”，[allDataArray计数])；

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

看起来您在这里正在重新发明轮子(几十年前已经解决了排序问题)，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"]];
}]