自我保留在这个Objective-C块中吗? [英] Is self retained within this Objective-C block?
问题描述
当我在Objective-C中有一个看起来像这样的块时:
When I have a block in Objective-C that looks like this:
self.request = [[ASIHTTPRequest requestWithURL:...
[self.longPollRequest setCompletionBlock:^{
NSLog(@"%@", self.request.responseString);
}];
它会保留 self
还是明确保留 self.request
?
will it retain self
or explicitly retain self.request
?
推荐答案
作为块编程主题说:
在引用计数环境中,当您引用
Objective-C对象时,默认为
阻止,保留
。即使你
只是引用对象的实例变量
也是如此。使用__block存储类型
修饰符标记为
的对象变量不会保留。
In a reference-counted environment, by default when you reference an Objective-C object within a block, it is retained. This is true even if you simply reference an instance variable of the object. Object variables marked with the __block storage type modifier, however, are not retained.
如果在方法的实现中使用块,对象
实例变量的内存管理规则
更微妙:
If you use a block within the implementation of a method, the rules for memory management of object instance variables are more subtle:
如果通过引用访问实例变量,则self为
保留;
If you access an instance variable by reference, self is retained;
如果按
值访问实例变量,则保留变量。
If you access an instance variable by value, the variable is retained.
您在块中引用 self
,因此 self
将被保留。
you reference self
in block, so self
is retained.
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