ios - 将对象从 Parse 添加到 UITableView 错误的数组

Question

我正在尝试使用从 Parse 中检索到的对象来填充 UITableView。
这些项目重新调整好，当我尝试将它们用于我的 _appliances NSArray 我得到:

'NSInvalidArgumentException', reason: '-[__NSCFString count]: 无法识别的选择器发送到实例

控制台将我的 _appliances array 打印为:

014-07-27 18:24:16.249 myapp[15839:60b] Fan
2014-07-27 18:24:16.249 myapp[15839:60b] kettle 
2014-07-27 18:24:16.250 myapp[15839:60b] Projector 

viewDidLoad:

    PFQuery *queryApplianceClass = [PFQuery queryWithClassName:@"savedAppliances"];

    [queryApplianceClass selectKeys:@[@"appliance"]];

    [queryApplianceClass orderByDescending:@"updatedAt"];

    queryApplianceClass.limit = 100;

    [queryApplianceClass findObjectsInBackgroundWithBlock:^(NSArray *applianceObjects, NSError *error) {
        if (!error) {


            for (PFObject *applianceList in applianceObjects) {
                 NSLog(@"%@", applianceList[@"appliance"]); //Prints to console as above

                  //Array of Appliances from database
                 _appliances = applianceList[@"appliance"]; 

            }


        }
        else {

            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
      }];

Answer 1

您不断将 NSString 值分配给 _appliances 数组变量。我相信你想要这个:

[queryApplianceClass findObjectsInBackgroundWithBlock:^(NSArray *applianceObjects, NSError *error) {
    if (applianceObjects) {
        NSMutableArray *appliances = [NSMutableArray array];
        for (PFObject *applianceList in applianceObjects) {
             NSLog(@"%@", applianceList[@"appliance"]); //Prints to console as above
             //Array of Appliances from database
             [appliances addObject:applianceList[@"appliance"]]; 
        }
        _appliances = appliances;
    }
    else {
        NSLog(@"Error: %@ %@", error, [error userInfo]);
    }
  }];

另请注意，如果 applianceObjects 为 nil，则应仅检查error。