在块中使用弱对象时崩溃

Question

我的代码是这样的：

Member *member = [Member new];
__weak __typeof(self) weakSelf = self
member.gotoPageBlock = ^(NSString *url) {
    __strong __typeof(weakSelf) self = weakSelf
    [self goToPageWithURL:[NSURL URLWithString:url]];
};

很少会崩溃，这次崩溃的栈顶是这样的：

Exception Type:  SIGSEGV
Exception Codes: SEGV_ACCERR at 0x365722298
Triggered by Thread:  0
Thread 0 Crashed:
0   libobjc.A.dylib                 0x0000000182794bb4 _objc_loadWeakRetained :156 (in libobjc.A.dylib)

执行块时发生崩溃。
有人知道怎么回事吗？

Answer 1

不需要再次强大自己所以，删除此行__strong __typeof(weakSelf) self = weakSelf然后应该可以正常工作

使用这个

Member *member = [Member new];
__weak __typeof(self) weakSelf = self
member.gotoPageBlock = ^(NSString *url) {
    //the difference is here
    [weakSelf goToPageWithURL:[NSURL URLWithString:url]];
};

在执行时失去所有权部分查看此https://sectionfive.net/blog/2014/11/24/arc-exploration-and-pitfalls/以获取更多信息

在块中使用弱对象时崩溃

Crash when use weak obj in block

block

objective-c

automatic-ref-counting