Xcode9.3 解决Block implicitly retains 'self'; explicitly mention 'self' to indicate this...警告

升级到Xcode9.3之后，大括号里声明的属性，在Block里面就会出现Block implicitly retains 'self'; explicitly mention 'self' to indicate this...的警告，大量这样声明的属性，产生了大量的黄色警告⚠️，很烦人！解决办法如下图所示：

在Build Setting里面搜索Implicit retain of 'self' within blocks里面从YES设置为NO即可，亲测有效！