iOS could not set nil as the value for the key

从数据库中请求到的数据往往存在空值, 这时前台便无法处理数据, 赋值model属性的时候出现: could not set nil as the value for the key的报错.这时可用下列方式解决:

1. 在model的基类中重写setnilvalueforkey:

- (void)setNilValueForKey:(NSString *)key{    [self setValue:@"" forKey:key];}

2. 另外网上给出了另一个解决方案, 你如果使用网络请求类是AFN那么可以通过设置AFN中responseSerializer的removesKeysWithNullValues属性来规避空值

/** Whether to remove keys with `NSNull` values from response JSON. Defaults to `NO`. */@property (nonatomic, assign) BOOL removesKeysWithNullValues;

((AFJSONResponseSerializer *)session.responseSerializer).removesKeysWithNullValues