NSSortDescriptor可以根據(jù)數(shù)組中對象的屬性來排序
為排序數(shù)組的每個屬性創(chuàng)建NSSortDescriptor對象瞻讽，將所有這些對象放入一個數(shù)組中噩峦，該數(shù)組將會在后面用作參數(shù)骆膝。使用NSArray類的sortedArrayUsingDescripors:方法并將NSSortDescriptor對象數(shù)組作為參數(shù)傳遞過去缅阳，會返回一個排好序的數(shù)組
創(chuàng)建一個OS X 的Application含蓉，選擇Command Line Tool以政，語言為Objective-C
- 首先創(chuàng)建一個Person類用于排序
Person.h
@interface Person : NSObject
@property (nonatomic, copy) NSString *firstName;
@property (nonatomic, copy) NSString *lastName;
@property (nonatomic, assign) NSInteger age;
-(instancetype)initWithFirstName:(NSString *)fName lastName:(NSString *)lName age:(NSInteger) age;
/**
* 輸出狀態(tài)
*/
-(void)printState;
@end
Person.m
@implementation Person
-(instancetype)initWithFirstName:(NSString *)fName lastName:(NSString *)lName age:(NSInteger)age {
self = [super init];
if (self) {
self.firstName = fName;
self.lastName = lName;
self.age = age;
}
return self;
}
-(void)printState {
NSLog(@"Name is %@ %@ is %ld years old",_firstName, _lastName, _age);
}
@end
- 在main.m中排序
#import "Person.h"
int main(int argc, const char * argv[]) {
Person *p1 = [[Person alloc] initWithFirstName:@"Wenxuan" lastName:@"Huo" age:21];
Person *p2 = [[Person alloc] initWithFirstName:@"MaHa" lastName:@"B" age:30];
Person *p3 = [[Person alloc] initWithFirstName:@"MeKe" lastName:@"C" age:30];
Person *p4 = [[Person alloc] initWithFirstName:@"MaLian" lastName:@"A" age:30];
Person *p5 = [[Person alloc] initWithFirstName:@"HoHo" lastName:@"A" age:40];
Person *p6 = [[Person alloc] initWithFirstName:@"Guo" lastName:@"Zhong" age:5000];
// 包含所有Person的數(shù)組
NSArray *peopleArray = @[p1, p2, p3, p4, p5, p6];
// 為每個屬性創(chuàng)建NSSortDescriptor對象
NSSortDescriptor * sdFirstName = [NSSortDescriptor sortDescriptorWithKey:@"firstName" ascending:YES];
NSSortDescriptor * sdLastName = [NSSortDescriptor sortDescriptorWithKey:@"lastName" ascending:YES];
NSSortDescriptor * sdAge = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:YES];
// 設(shè)置排序優(yōu)先級鞭执，并組成數(shù)組司顿。這里優(yōu)先級最高為age，之后是firstName
NSArray * sortedArray = [peopleArray sortedArrayUsingDescriptors:@[sdAge, sdLastName, sdFirstName]];
// 為數(shù)組中每個元素執(zhí)行方法兄纺，輸出狀態(tài)
[sortedArray makeObjectsPerformSelector:@selector(printState)];
return 0;
}
輸出結(jié)果：
Name is Wenxuan Huo is 21 years old
Name is MaLian A is 30 years old
Name is MaHa B is 30 years old
Name is MeKe C is 30 years old
Name is HoHo A is 40 years old
Name is Guo Zhong is 5000 years old
下面測試另一種排序方式
// 優(yōu)先級最高為firstName大溜，之后是age
NSArray * sortedArray = [peopleArray sortedArrayUsingDescriptors:@[sdLastName, sdAge, sdFirstName]];
[sortedArray makeObjectsPerformSelector:@selector(printState)];
輸出結(jié)果:
Name is MaLian A is 30 years old
Name is HoHo A is 40 years old
Name is MaHa B is 30 years old
Name is MeKe C is 30 years old
Name is Wenxuan Huo is 21 years old
Name is Guo Zhong is 5000 years old
Nice
