objective-c 的引用计数管理_objective-c引用计数器操作-优快云博客

本文链接：https://blog.youkuaiyun.com/infinite_sh/article/details/43268535

本文通过一个Objective-C自定义类的实例，演示了对象初始化、内存分配及释放的过程，并强调了alloc、new、copy方法创建的对象才需调用release进行管理。

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直接上代码，简单

为了看清楚对象的分配和释放过程，继承了NSMutalbeArray，没有什么实用意义。

#import <Foundation/Foundation.h>

@interface ClassA : NSMutableArray
-(void) print: (NSString *)desc;
@end

@implementation ClassA
-(id) init
{
	self = [super init];
	NSLog(@"init retainCount=%i", [self retainCount]);
	return self;
}

-(void) dealloc
{
	NSLog(@"dealloc retainCount=%i", [self retainCount]);
	[super dealloc];
}

-(void) print: (NSString *)desc
{
	NSLog(@"%@ retainCount=%i", desc, [self retainCount]);
}
@end

void print(NSString *desc, int count)
{
	NSLog(@"%@ retain count=%i", desc, count);
}

int main(const int argc, const char *argv[])
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init];

    ClassA *a0 = [ClassA arrayWithCapacity: 10];
    [a0 print: @"arrayWithCapacity"];
    ClassA *a1 = [ClassA new];
    [a1 print: @"new"];

    [pool drain];
    [a1 print: @"after pool drain"];
    [a1 release];

	return 0;
}

看看输出结果

2015-01-29 11:08:51.953 cpro[5128] init retainCount=1
2015-01-29 11:08:51.969 cpro[5128] arrayWithCapacity retainCount=1
2015-01-29 11:08:51.969 cpro[5128] init retainCount=1
2015-01-29 11:08:51.969 cpro[5128] new retainCount=1
2015-01-29 11:08:51.969 cpro[5128] dealloc retainCount=1
2015-01-29 11:08:51.969 cpro[5128] after pool drain retainCount=1
2015-01-29 11:08:51.969 cpro[5128] dealloc retainCount=1

内存管理有个原则：只有使用alloc new copy方法获取的对象才需要调用release。