假设对象A有一个属性:
@property (nonatomic, strong) Foo * bar;
在实现中合成为:
@synthesize bar = _bar;
对象B操纵a Foo **,如本示例中对象A的调用:
Foo * temp = self.bar;
[objB doSomething:&temp];
self.bar = temp;
doSomething:方法的正确声明是什么？此外,假设在我有机会设置属性之前可以释放对象Bbar(从而获取指向的实例的所有权temp) - 我如何告诉ARC切换拥有的引用？换句话说,如果我想让以下示例代码段起作用,我将如何处理ARC问题？
Foo * temp = self.bar; // Give it a reference to some current value
[objB doSomething:&temp]; // Let it modify the reference
self.bar = nil; // Basically release whatever we have
_bar = temp; // Since we're …我正在尝试将指针传递给指向某个方法的指针,但显然ARC在如何操作方面存在一些问题.这里有两种方法:
+ (NSString *)personPropertyNameForIndex:(kSHLPersonDetailsTableRowIndex)index
{
static NSArray *propertyNames = nil;
(nil == propertyNames) ?
[self SHL_initPersonPropertyNamesWithArray:&propertyNames] : NULL;
}
+ (void)SHL_initPersonPropertyNamesWithArray:(NSArray **)theArray
{
*theArray = [[NSArray alloc]
initWithObjects:@"name", @"email", @"birthdate", @"phone", nil];
}
我收到以下错误:
自动引用计数问题:将非本地对象的地址传递给__autoreleasing参数以进行回写
在出现以下命令的行上:
[self SHL_initPersonPropertyNamesWithArray:&propertyNames] : NULL;
我正在尝试用ios5制作应用程序,我真的很困惑,为什么会发生这种情况.有人可以帮我解释一下为什么出现错误时出现错误
将非本地对象的地址传递给__autoreleasing参数以进行回写
以下调用导致错误
// note the following method returns _inStream and _outStream with a retain count that the caller must eventually release
if (![netService getInputStream:&_inStream outputStream:&_outStream]) {
NSLog(@"error in get input and output streams");
return;
}
我的班级.h
NSInputStream *_inStream;
NSOutputStream *_outStream;
@property (nonatomic, strong) NSInputStream *_inStream;
@property (nonatomic, strong) NSOutputStream *_outStream;
我的班级.m
@synthesize _inStream;
@synthesize _outStream;
所述的getInputStream是NSNetService类方法
请在下面的NSNetService类getInputStream实现
/* Retrieves streams from the NSNetService instance. The instance's delegate methods are not called. Returns YES if the …