iOS开发中，如何将OC语言的线程安全单例成？
摘要：SingleClass.h SingleClass.hFirst Created by xxx on 202229.#import <FoundationFoundatio
SingleClass.h
//
// SingleClass.h
// First
//
// Created by xxx on 2022/2/9.
//
#import <Foundation/Foundation.h>
@interface SingleClass : NSObject
+(instancetype) sharedInstance;
@end
SingleClass.m
//
// SingleClass.m
// First
//
// Created by xxx on 2022/2/9.
//
#import "SingleClass.h"
@implementation SingleClass
+ (instancetype)sharedInstance {
static SingleClass * ins = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
ins = [[super allocWithZone:nil] init];
});
return ins;
}
+(id)allocWithZone:(NSZone *)zone {
return [self sharedInstance];
}
-(id)copyWithZone:(NSZone *) zone {
return [[self class] sharedInstance];
}
-(id)mutableCopyWithZone:(NSZone *) zone {
return [[self class] sharedInstance];
}
@end
测试
#import "SingleClass.h"
SingleClass *ins1 = [SingleClass sharedInstance];
NSLog(@"SingleClass obj1 = %@.", ins1);
SingleClass *ins2 = [[SingleClass alloc] init];
NSLog(@"SingleClass obj2 = %@.", ins2);
SingleClass *ins3 = [SingleClass new];
NSLog(@"SingleClass obj3 = %@.", ins3);
if (ins1 == ins2 && ins1 == ins3) {
NSLog(@"SingleClass test success");
} else {
NSLog(@"SingleClass test failed");
}