这个问题在这里已有答案:
我有一个NSArray
的NSDictionaries
,在NSDictionary
我有一个名为'rowID'的元素,它被保存为NSString
,但是保存在其中的所有内容都是一个数字..但仍然是一个字符串值。
我想知道如何根据这个值对数组进行排序,但是在排序1-100方面,目前当我对它进行排序时,它首先出现....当它应该是1-10时。
这就是我的排序方式:
NSArray *tempSortedItemsArray = [itemArray sortedArrayUsingDescriptors:
@[[NSSortDescriptor
sortDescriptorWithKey:@"rowID" ascending:YES]]];
试试这个 :-
NSArray *aSortedArray = [itemArray sortedArrayUsingComparator:^(NSMutableDictionary *obj1,NSMutableDictionary *obj2) {
NSString *num1 =[obj1 objectForKey:@"rowID"];
NSString *num2 =[obj2 objectForKey:@"rowID"];
return (NSComparisonResult) [num1 compare:num2 options:(NSNumericSearch)];
}];
您可以按照以下代码进行数字排序: -
NSMutableArray *tmpAr = [[NSMutableArray alloc] init];
NSMutableDictionary *tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number5"];
[tmpDict setObject:@"5" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number3"];
[tmpDict setObject:@"3" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number2"];
[tmpDict setObject:@"2" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number1"];
[tmpDict setObject:@"1" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number4"];
[tmpDict setObject:@"4" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number25"];
[tmpDict setObject:@"25" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number10"];
[tmpDict setObject:@"10" forKey:@"id"];
[tmpAr addObject:tmpDict];
tmpDict = [[NSMutableDictionary alloc] init];
[tmpDict setObject:@"name" forKey:@"number7"];
[tmpDict setObject:@"7" forKey:@"id"];
[tmpAr addObject:tmpDict];
NSLog(@"tmpar1 = %@",tmpAr);
[tmpAr sortUsingComparator:
^(id obj1, id obj2)
{
NSInteger value1 = [[obj1 objectForKey: @"id"] intValue];
NSInteger value2 = [[obj2 objectForKey: @"id"] intValue];
if (value1 > value2)
{
return (NSComparisonResult)NSOrderedDescending;
}
if (value1 < value2)
{
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}];
NSLog(@"tmpar2 = %@",tmpAr);
如果使用initWithKey:ascending:selector:
或sortDescriptorWithKey:ascending:comparator:
创建排序描述符,则可以指定用于比较对象的选择器。
现在问题是哪个选择器通过。那么你可以在NSString上创建一个Category来实现一个自定义排序函数,该函数根据字符串的数值进行排序。记得从文件:
选择器必须指定由keyPath标识的属性值实现的方法。用于比较的选择器传递一个参数,即要与self进行比较的对象,并且必须返回相应的NSComparisonResult常量。选择器必须具有与以下相同的方法签名:
- (NSComparisonResult)localizedCompare:(NSString *)aString
指定属性键的对象(相对于集合中的每个对象)必须实现用于创建排序描述符的比较选择器。如果未指定自定义选择器,则对象必须实现compare:。
试试这样: -
NSDictionary *row1 = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"rowId",nil];
NSDictionary *row2 = [NSDictionary dictionaryWithObjectsAndKeys:@"2",@"rowId",nil];
NSDictionary *row3 = [NSDictionary dictionaryWithObjectsAndKeys:@"3",@"rowId",nil];
NSMutableArray *arr = [[NSMutableArray alloc] initWithObjects:row1,row2,row3,nil];
NSSortDescriptor *desc = [[NSSortDescriptor alloc] initWithKey:@"rowId" ascending:YES];
[arr sortUsingDescriptors:[NSArray arrayWithObject:desc]];
// before sort
NSLog(@"Before %@",arr);
[arr sortedArrayUsingComparator:^(NSDictionary *item1, NSDictionary *item2) {
NSString *first = [item1 objectForKey:@"rowId"];
NSString *second = [item2 objectForKey:@"rowId"];
return [first compare:second options:NSNumericSearch];
}];
// After sort
NSLog(@"After %@",arr);