转载：Existing ivar 'title' for unsafe_unretained property 'title' must be __unsafe_unretained

iOS项目中，启用 ARC特性的情况下，属性（ property ）的从属限定符必须与实例变量（ instance variable ）的从性限定符一致，否则将遇到标题中这样的编译错误。最直接的处理方式是去掉实例变量的声明。

http://stackoverflow.com/questions/8368157/existing-ivar-title-for-unsafe-unretained-property-title-must-be-unsafe-un/8368240#8368240

亮点：

OR you can just omit the ivar declaration, and just let the compiler do that for you as well. Like this:

@interface Movie : NSObject

@property(assign) NSString *title;

@property(assign) int rating;

@property(assign) int year;

@end

Hope that helps.

谷丽萍