// // Person.h #import <Foundation/Foundation.h> @interface Person : NSObject @property (nonatomic, assign) int age; + (instancetype)person; - (instancetype)initWithAge:(int)age; + (instancetype)personWithAge:(int)age; @end
// Person.m #import "Person.h" @implementation Person //提供构造方法的时候也要提供类工厂方法(API里面是这么写的),如果是MRC还要提供antorelease. + (instancetype)person //类工厂方法 { return [[[self alloc] init] autorelease]; } - (instancetype)initWithAge:(int)age{ //构造方法 if (self = [super init]) { _age = age; } return self; } + (instancetype)personWithAge:(int)age //类工厂方法 { /* Person *p = [[self alloc] init]; p.age = age; return [p autorelease]; */ return [[[self alloc] initWithAge:age] autorelease]; //self = Person; } - (void)dealloc { NSLog(@"%s", __func__); [super dealloc]; } @end
// // main.m // auatorelease应用场景 #import <Foundation/Foundation.h> #import "Person.h" int main(int argc, const char * argv[]) { @autoreleasepool { Person *p = [[[Person alloc] init] autorelease]; p.age = 10; NSLog(@"age = %i", p.age); Person *p1 = [[[Person alloc] init] autorelease]; Person *p2 = [[[Person alloc] init] autorelease]; Person *1p = [Person person]; 1p.age = 10; NSLog(@"age = %i", 1p.age); // 注意: Foundation框架的类, 但凡是通过类工厂方法创建的对象都是autorelease的 [[NSString alloc] init]; [NSString string]; // [NSString alloc] initWithString:(NSString *) // [NSString stringWithString:(NSString *)]; Person *p = [[[Person alloc] initWithAge:10] autorelease]; NSLog(@"age = %i", p.age); Person *p = [Person personWithAge:10]; NSLog(@"age = %i", p.age); } return 0; }