概述：NSSortDescriptor是用来指定排序规则, 对集合等进行排序时指定结果的排序规则;
他可以对一个类的某个属性(下文中方法中的key参数)指定排序规则, 也可以对一个字符串集合进行指定排序规则, 这时, 只需要把参数key赋值为nil即可。
iOS中的集合都有相应的扩展方法来使用NSSortDescriptor:
-(NSArray<ObjectType> *)sortedArrayUsingDescriptors:(NSArray<NSSortDescriptor *> *)sortDescriptors
具体的方法有：
1.
+ (instancetype)sortDescriptorWithKey:(nullable NSString *)key ascending:(BOOL)ascending NS_AVAILABLE(10_6, 4_0);
参数：
key : 排序key, 某个对象的属性名称
ascending : 是否升序, YES-升序, NO-降序
举一些例子：
NSMutableArray *myMutableArr = [[NSMutableArray alloc] init] ;
NSDictionary *dicOne = [NSDictionary dictionaryWithObjectsAndKeys:@"1",@"price",@"2",@"number", nil];
NSDictionary *dicTWo = [NSDictionary dictionaryWithObjectsAndKeys:@"6",@"price",@"5",@"number", nil];
NSDictionary *dicThree = [NSDictionary dictionaryWithObjectsAndKeys:@"3",@"price",@"1",@"number", nil];
NSDictionary *dicFour = [NSDictionary dictionaryWithObjectsAndKeys:@"4",@"price",@"3",@"number", nil];
[myMutableArr addObject:dicOne];
[myMutableArr addObject:dicTWo];
[myMutableArr addObject:dicThree];
[myMutableArr addObject:dicFour];
NSArray *sortDescriptors = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"price" ascending:YES]];
[myMutableArr sortUsingDescriptors:sortDescriptors];
NSLog(@"排序后的数组%@",myMutableArr);
NSSortDescriptor *descriptor = [[NSSortDescriptor alloc] initWithKey:@"self" ascending:YES];
NSArray *descriptors = [NSArray arrayWithObject:descriptor];
NSArray *reverseDayInMonthArray = [displayKeyDataArray sortedArrayUsingDescriptors:descriptors];
比较数字字符串和数字
NSArray *array1 = @[@"5", @"7", @"9", @"12", @"35", @"1", @"3"];
NSArray *array2 = @[@5, @6, @9, @1, @3, @19];
NSSortDescriptor *ds1 = [NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES];
NSArray *sortedArray1 = [array1 sortedArrayUsingDescriptors:@[ds1]];
NSLog(@"sortedArray1:%@",sortedArray1);
NSArray *sortedArray2 = [array2 sortedArrayUsingDescriptors:@[ds1]];
NSLog(@"sortedArray2:%@",sortedArray2);
输出结果：
sortedArray1:[
"1",
"12",
"3",
"35",
"5",
"7",
"9"
]
sortedArray2:[
1,
3,
5,
6,
9,
19
]
NSMutableArray比较
NSMutableArray *array3 = [@[@5, @6, @9, @1, @3, @19] mutableCopy];
[array3 sortUsingDescriptors:@[ds1]];
NSLog(@"sortedArray3:%@",array3);
输出结果：
sortedArray3:[
1,
3,
5,
6,
9,
19
]
比较NSDate数组
NSArray *timeArray = @[[NSDate getSGDateByString:@"2020-12-02 14:00:00" format:@"yyyy-MM-dd HH:mm:ss"], [NSDate getSGDateByString:@"2020-12-12 14:00:00" format:@"yyyy-MM-dd HH:mm:ss"], [NSDate getSGDateByString:@"2020-11-22 14:00:00" format:@"yyyy-MM-dd HH:mm:ss"], [NSDate getSGDateByString:@"2020-12-02 14:00:01" format:@"yyyy-MM-dd HH:mm:ss"]];
NSSortDescriptor *ds2 = [NSSortDescriptor sortDescriptorWithKey:nil ascending:YES];
NSArray *sortedTimeArray = [timeArray sortedArrayUsingDescriptors:@[ds2]];
NSLog(@"sortedTimeArray:%@",sortedTimeArray);
输出结果：
sortedTimeArray:(
"2020-11-22 14:00:00 +0000",
"2020-12-02 14:00:00 +0000",
"2020-12-02 14:00:01 +0000",
"2020-12-12 14:00:00 +0000"
)
比较NSDictionary数组，根据字典中某个key的value值进行排序，使用两个条件进行排序
NSArray *dicArray = @[@{@"name":@"1A", @"age":@14, @"score":@99.9}, @{@"name":@"1C", @"age":@14, @"score":@79.9}, @{@"name":@"1X", @"age":@12, @"score":@99.6}, @{@"name":@"1B", @"age":@4, @"score":@89.9}, @{@"name":@"2A", @"age":@12, @"score":@99}, @{@"name":@"3C", @"age":@14, @"score":@99.9}, @{@"name":@"1X", @"age":@15, @"score":@69.9}];
NSSortDescriptor *ds3 = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:YES];
NSSortDescriptor *ds4 = [NSSortDescriptor sortDescriptorWithKey:@"score" ascending:NO];
NSArray *sortedDicArray = [dicArray sortedArrayUsingDescriptors:@[ds4,ds3]];
NSLog(@"sortedDicArray:%@",sortedDicArray);
输出结果：
sortedDicArray:[
{
"name" : "1A",
"age" : 14,
"score" : 99.900000000000006
},
{
"name" : "3C",
"age" : 14,
"score" : 99.900000000000006
},
{
"name" : "1X",
"age" : 12,
"score" : 99.599999999999994
},
{
"name" : "2A",
"age" : 12,
"score" : 99
},
{
"name" : "1B",
"age" : 4,
"score" : 89.900000000000006
},
{
"name" : "1C",
"age" : 14,
"score" : 79.900000000000006
},
{
"name" : "1X",
"age" : 15,
"score" : 69.900000000000006
}
]
比较NSDictionary数组，字典中某个key的value值为字典，根据子字典中某个key的value值进行排序
NSArray *dicdicArray = @[@{@"name":@"1A", @"age":@14, @"score":@{@"yuwen":@87}}, @{@"name":@"1C", @"age":@14, @"score":@{@"yuwen":@79.9}}, @{@"name":@"1X", @"age":@12, @"score":@{@"yuwen":@99.6}}, @{@"name":@"1B", @"age":@4, @"score":@{@"yuwen":@89.9}}, @{@"name":@"2A", @"age":@12, @"score":@{@"yuwen":@99}}, @{@"name":@"3C", @"age":@14, @"score":@{@"yuwen":@99}}, @{@"name":@"1X", @"age":@15, @"score":@{@"yuwen":@69.9}}];
NSSortDescriptor *ds5 = [NSSortDescriptor sortDescriptorWithKey:@"score.yuwen" ascending:YES];
NSArray *sortedDicdicArray = [dicdicArray sortedArrayUsingDescriptors:@[ds5,ds3]];
NSLog(@"sortedDicdicArray:%@",sortedDicdicArray);
输出结果：
sortedDicdicArray:[
{
"name" : "1X",
"age" : 15,
"score" : {
"yuwen" : 69.900000000000006
}
},
{
"name" : "1C",
"age" : 14,
"score" : {
"yuwen" : 79.900000000000006
}
},
{
"name" : "1A",
"age" : 14,
"score" : {
"yuwen" : 87
}
},
{
"name" : "1B",
"age" : 4,
"score" : {
"yuwen" : 89.900000000000006
}
},
{
"name" : "2A",
"age" : 12,
"score" : {
"yuwen" : 99
}
},
{
"name" : "3C",
"age" : 14,
"score" : {
"yuwen" : 99
}
},
{
"name" : "1X",
"age" : 12,
"score" : {
"yuwen" : 99.599999999999994
}
}
]
2.
+ (instancetype)sortDescriptorWithKey:(nullable NSString *)key ascending:(BOOL)ascending selector:(nullable SEL)selector NS_AVAILABLE(10_6, 4_0);
参数:
key : 排序key, 某个对象的属性名称
ascending : 是否升序, YES-升序, NO-降序
selector : 自定义排序规则, 如果需要自己定义排序规则, 可传递此方法, 这个使用相对比较复杂; 如果待比较的属性是字符串(NSString)类型, 可使用其默认的方法: localizedStandardCompare:
3. 也可以使用NSComparisonResult，自己提供一个排序规则
+ (instancetype)sortDescriptorWithKey:(nullable NSString *)key ascending:(BOOL)ascending comparator:(NSComparator)cmptr NS_AVAILABLE(10_6, 4_0);
参数:
key : 排序key, 某个对象的属性名称
ascending : 是否升序, YES-升序, NO-降序
cmptr: 一个block, 可以在其中指定比较规则
最终的排序顺序依赖 -> ascending和cmptr进行合并操作 升序为yes，降序为no，两者进行合并操作 NO、NO-> YES； YES、YES->YES； YES、NO->NO
//NSSortDescriptor中 + (instancetype)sortDescriptorWithKey:(nullable NSString *)key ascending:(BOOL)ascending comparator:(NSComparator)cmptr;
//[obj1 compare:obj2] 升序
//[obj2 compare:obj2] 降序
//ascending 与 comparator会进行合并操作 升序为yes，降序为no，两者进行合并操作 NO、NO-> YES； YES、YES->YES； YES、NO->NO
举一些例子：
NSArray *dicArray = @[@{@"1A":@14}, @{@"1C":@12}, @{@"1X":@12}, @{@"1B":@4}, @{@"2A":@11}, @{@"3C":@9}, @{@"1X":@19}];
NSSortDescriptor *ds3 = [NSSortDescriptor sortDescriptorWithKey:nil ascending:nil comparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
return [[obj1 allValues][0] compare:[obj2 allValues][0]];
}];
NSArray *sortedComparatorDicArray = [dicArray sortedArrayUsingDescriptors:@[ds3]];
NSLog(@"Comparator - sortedDicArray:%@",sortedComparatorDicArray);// ascending:nil NSComparisonResultYES -> NO 降序
Comparator - sortedDicArray:[
{
"1X" : 19
},
{
"1A" : 14
},
{
"1C" : 12
},
{
"1X" : 12
},
{
"2A" : 11
},
{
"3C" : 9
},
{
"1B" : 4
}
]
NSArray *dicdicArray = @[@{@"name":@"1A", @"age":@14, @"score":@{@"yuwen":@87}}, @{@"name":@"1C", @"age":@14, @"score":@{@"yuwen":@79.9}}, @{@"name":@"1X", @"age":@12, @"score":@{@"yuwen":@99.6}}, @{@"name":@"1B", @"age":@4, @"score":@{@"yuwen":@89.9}}, @{@"name":@"2A", @"age":@12, @"score":@{@"yuwen":@99}}, @{@"name":@"3C", @"age":@14, @"score":@{@"yuwen":@99}}, @{@"name":@"1X", @"age":@15, @"score":@{@"yuwen":@69.9}}];
NSSortDescriptor *dsdic = [NSSortDescriptor sortDescriptorWithKey:@"score" ascending:NO comparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
NSNumber *num1 = [obj1 allValues][0];
NSNumber *num2 = [obj2 allValues][0];
return [num2 compare:num1];
}];
NSArray *sortedDicDicArray = [dicdicArray sortedArrayUsingDescriptors:@[dsdic]];
NSLog(@"Comparator - sortedDicDicArray:%@",sortedDicDicArray);//ascending:NO NSComparisonResult NO -> NO 降序
Comparator - sortedDicDicArray:[
{
"name" : "1X",
"age" : 15,
"score" : {
"yuwen" : 69.900000000000006
}
},
{
"name" : "1C",
"age" : 14,
"score" : {
"yuwen" : 79.900000000000006
}
},
{
"name" : "1A",
"age" : 14,
"score" : {
"yuwen" : 87
}
},
{
"name" : "1B",
"age" : 4,
"score" : {
"yuwen" : 89.900000000000006
}
},
{
"name" : "2A",
"age" : 12,
"score" : {
"yuwen" : 99
}
},
{
"name" : "3C",
"age" : 14,
"score" : {
"yuwen" : 99
}
},
{
"name" : "1X",
"age" : 12,
"score" : {
"yuwen" : 99.599999999999994
}
}
]
NSArray *dicindicArray = @[@{@"1A":@{@"yuwen":@87}}, @{@"1C":@{@"yuwen":@79.9}}, @{@"1X":@{@"yuwen":@99.6}}, @{@"1B":@{@"yuwen":@89.9}}, @{@"2A":@{@"yuwen":@99}}, @{@"3C":@{@"yuwen":@99}}, @{@"1X":@{@"yuwen":@69.9}}];
NSSortDescriptor *dsdicindic = [NSSortDescriptor sortDescriptorWithKey:nil ascending:NO comparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
return [[[obj2 allValues][0] allValues][0] compare:[[obj1 allValues][0] allValues][0]];
}];
NSArray *sortedDicInDicArray = [dicindicArray sortedArrayUsingDescriptors:@[dsdicindic]];
NSLog(@"Comparator - sortedDicInDicArray:%@",sortedDicInDicArray);//ascending:NO NSComparisonResultNO-> NO 降序
Comparator - sortedDicInDicArray:[
{
"1X" : {
"yuwen" : 69.900000000000006
}
},
{
"1C" : {
"yuwen" : 79.900000000000006
}
},
{
"1A" : {
"yuwen" : 87
}
},
{
"1B" : {
"yuwen" : 89.900000000000006
}
},
{
"2A" : {
"yuwen" : 99
}
},
{
"3C" : {
"yuwen" : 99
}
},
{
"1X" : {
"yuwen" : 99.599999999999994
}
}
]
NSSortDescriptor *dsNormal = [NSSortDescriptor sortDescriptorWithKey:nil ascending:NO comparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
return [obj1 compare:obj2];
}];
NSArray *array1 = @[@"5", @"7", @"9", @"12", @"35", @"1", @"3"];
NSArray *array2 = @[@5, @6, @9, @1, @3, @19];
NSArray *sortedArray1 = [array1 sortedArrayUsingDescriptors:@[dsNormal]];
NSLog(@"Comparator - sortedArray1:%@",sortedArray1);
NSArray *sortedArray2 = [array2 sortedArrayUsingDescriptors:@[dsNormal]];
NSLog(@"Comparator - sortedArray2:%@",sortedArray2);//ascending:NO NSComparisonResult YES-> NO降序
Comparator - sortedArray1:[
"9",
"7",
"5",
"35",
"3",
"12",
"1"
]
2020-12-04 10:46:05.448428+0800 InterTec[69682:1897614] Comparator - sortedArray2:[
19,
9,
6,
5,
3,
1
]
NSMutableArray *tempArray = [NSMutableArray new];
[dicArray enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
[tempArray addObject:@{@"name":[obj allKeys][0], @"value":[obj allValues][0]}];
}];
NSSortDescriptor *ds4 = [NSSortDescriptor sortDescriptorWithKey:@"value" ascending:YES];
NSArray *sortedDicArray = [tempArray sortedArrayUsingDescriptors:@[ds4]];
NSLog(@"Comparator - normal -sortedDicArray:%@",sortedDicArray);//ascending:YES 升序
Comparator - normal -sortedDicArray:[
{
"name" : "1B",
"value" : 4
},
{
"name" : "3C",
"value" : 9
},
{
"name" : "2A",
"value" : 11
},
{
"name" : "1C",
"value" : 12
},
{
"name" : "1X",
"value" : 12
},
{
"name" : "1A",
"value" : 14
},
{
"name" : "1X",
"value" : 19
}
]
NSSortDescriptor *ds5 = [NSSortDescriptor sortDescriptorWithKey:@"value" ascending:NO comparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {
return [obj1 compare:obj2];
}];
NSArray *sortedDicArray2 = [tempArray sortedArrayUsingDescriptors:@[ds5]];
NSLog(@"Comparator - ! -sortedDicArray:%@",sortedDicArray2); //ascending:NO NSComparisonResultYES，最终为NO，降序
Comparator - ! -sortedDicArray:[
{
"name" : "1X",
"value" : 19
},
{
"name" : "1A",
"value" : 14
},
{
"name" : "1C",
"value" : 12
},
{
"name" : "1X",
"value" : 12
},
{
"name" : "2A",
"value" : 11
},
{
"name" : "3C",
"value" : 9
},
{
"name" : "1B",
"value" : 4
}
]
