关于 NSUserDefaults setBool 的值取出后if判断不了的问题

使用 [[NSUserDefaults standardUserDefaults] setBool:(BOOL)value forKey:(NSString *)defaultName] 设置的值，如果用普通的objectForKey:取出的值是__NSCFBoolean类型，if语句无法判断，即使后加== YES也没用，还会出问题。

要用 [[NSUserDefaults standardUserDefaults] boolForKey:(NSString *)defaultName] 来取值，

同理：

- (void)setInteger:(NSInteger)value forKey:(NSString *)defaultName;
- (void)setFloat:(float)value forKey:(NSString *)defaultName;
- (void)setDouble:(double)value forKey:(NSString *)defaultName;
- (void)setBool:(BOOL)value forKey:(NSString *)defaultName;
- (void)setURL:(nullable NSURL *)url forKey:(NSString *)defaultName;

如上所示等入值方法，都用对应配套的取值方法

- (NSInteger)integerForKey:(NSString *)defaultName;
- (float)floatForKey:(NSString *)defaultName;
- (double)doubleForKey:(NSString *)defaultName;
- (BOOL)boolForKey:(NSString *)defaultName;
- (nullable NSURL *)URLForKey:(NSString *)defaultName;