Question

我有一个NSObject实体用于存储一些数据，如来自服务器的名称，id

NSObject文件如下所示，

@interface MyEntity : NSObject
@property(nonatomic,strong)NSString *userId;
@property(nonatomic,strong)NSString *userName;
- (id)initWithJSON:(NSDictionary *)dataDict;
@end

- (id)initWithJSON:(NSDictionary *)dataDict
{
   if (self = [super init])
   {
       self.userId = [dataDict objectForKeyNotNull:@"userId"] ;
       self.userName = [dataDict objectForKeyNotNull:@"userName"] ;
   }
   return self;
}

我将值从服务器存储到NSMutableArray，

NSMutableArray *array = [[NSMutableArray alloc] initWithArray:responseData[@"result"]];
for (NSDictionary *dict in array) {
        MyEntity *ent = [[MyEntity alloc] initWithJSON:dict];
        [myArray addObject:ent];
}

现在，我想使用NSPredicate通过某些用户名过滤NSMutableArray。我试过下面的代码，

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"ANY MyEntity.userName == %@", @"popo"];
NSArray *predicateFilteredArray = [myArray filteredArrayUsingPredicate:predicate];
[myArray removeAllObjects];
[myArray addObjectsFromArray:predicateFilteredArray];

它不起作用。我怎样才能做到这一点？

Answer 1

你只需要检查谓词的实体名称是否写为简单谓词就可以了，我的意思就是替换你的代码

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"ANY MyEntity.userName == %@", @"popo"];

使用

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"userName == %@", @"popo"];它会起作用。

使用NSPredicate过滤NSDictionary的NSMutableArray

1 个答案: