objective-c – 使用自动引用计数释放self的新模式是什么？

概述使用NSObject方法 – (id)awakeAfterUsingCoder：(NSCoder *)解码器作为示例,文档说： Allows an object, after being decoded, to substitute another object for itself. For example, an object that represents a font might, upo 使用NSObject方法 – (ID)awakeAfterUsingCoder：(NSCoder *)解码器作为示例,文档说：

Allows an object,after being decoded,to substitute another object
for itself. For example,an object that represents a Font might,upon
being decoded,release itself and return an existing object having the
same Font description as itself. In this way,redundant objects can be
eliminated.

通常你会这样做

[self release];return substitutedobject;

使用ARC,你必须离开这条线.这不会泄漏吗？或者我应该只相信NSCoder对象为我发布原始对象？如果是这样,为什么你必须首先用非ARC代码明确释放自己？

根据编译器文档中关于self的内容,我认为self = nil是不正确的：http://clang.llvm.org/docs/AutomaticReferenceCounting.html#misc.self

解决方法 如上所述,你不能写[self release];.另外,awakeAfterUsingCoder：不是初始化者 – 你可能不会重新分配自己.

Wouldn’t this leak?

是.在下面的程序中证明.

Or should I just trust the NSCoder object to release the original object for me?

没有.

下面是一种避免泄漏的方法 – 我不会称之为“新模式”,这只是我想到的第一种方法.它涉及自我的显式释放,在这种情况下显式保留结果：

#import <Foundation/Foundation.h>@interface MONBoolean : NSObject < NSCoding >- (ID)initWithBool:(bool)pBool;- (bool)isTrue;- (bool)isFalse;@endstatic Nsstring * const MONBoolean_KEY_value = @"MONBoolean_KEY_value";@implementation MONBoolean{    bool value;}- (ID)initWithBool:(bool)pBool{    self = [super init];    if (0 != self) {        value = pBool;    }    return self;}- (bool)isTrue{    return true == value;}- (bool)isFalse{    return false == value;}- (Nsstring *)description{    return [[Nsstring alloc] initWithFormat:@"<%s:%p> : %s",object_getClassname(self),self,self.isTrue ? "true" : "false"];}- (voID)encodeWithCoder:(NSCoder *)aCoder{    [aCoder encodeBool:value forKey:MONBoolean_KEY_value];}- (ID)initWithCoder:(NSCoder *)aDecoder{    self = [super init];    if (0 != self) {        value = [aDecoder decodeBoolForKey:MONBoolean_KEY_value];    }    return self;}- (ID)awakeAfterUsingCoder:(NSCoder *)aDecoder{    const bool b = value;    // cannot reassign self outsIDe of an initializer.    // if not released,will result in a leak:    CFRelease((__brIDge const voID*)self);    MONBoolean * result = [[MONBoolean alloc] initWithBool:b];    // Now we have to retain explicitly because this is    // an autoreleasing method:    CFRetain((__brIDge const voID*)result);    return result;}@endint main(int argc,const char * argv[]){    @autoreleasepool {        MONBoolean * a = [[MONBoolean alloc] initWithBool:true];        NSData * data = [NSKeyedArchiver archivedDataWithRootObject:a];        MONBoolean * b = [NSKeyedUnarchiver unarchiveObjectWithData:data];        NSLog(@"%@",b);    }    system("leaks name_OF_PROCESS_HERE");    return 0;}

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