在block函数中规避警告信息 "capturing

以形如

_fontValueChangedBlock = ^(){

[self.fontSmallButton addTarget:self action:@selector(btnFontSmallClicked) forControlEvents:UIControlEventTouchUpInside];

};

的代码为例，这个代码运行会报警告。"capturing self strongly in this block is likely to lead to a retain cycle”

要想消除这个警告，需要将代码改为如下形式：

__weak typeof(self) weakSelf = self;

_fontValueChangedBlock = ^(){

typeof(weakSelf) __strong strongSelf = weakSelf;

[strongSelf.fontSmallButton addTarget:strongSelf action:@selector(btnFontSmallClicked) forControlEvents:UIControlEventTouchUpInside];

};