从解析中获取对象并转换为字符串

Question

我正在尝试从解析中获取数据。有 4-5 个字符串格式的字段，并将它们显示在 IOS 故事板的下拉菜单中。

实际上有 9 列，包括解析默认列。他们创建数据、ACL、对象 ID 等等。

我只需要从解析中获取那些字符串格式的字段，我想在 UIViewController 中将它们显示为下拉菜单。对于下拉菜单，我是 UITableViewController。 serviceview.h

@interface ServiceViewController : UIViewController <UIPickerViewDelegate, UIPickerViewDataSource, UITableViewDataSource,UITableViewDelegate>

@property (strong, nonatomic)NSArray *selectionArray;

@property (weak, nonatomic) IBOutlet UILabel *resultLabel;

@property (weak, nonatomic) IBOutlet UIPickerView *servicepicker;

@property (weak, nonatomic) IBOutlet UITableView *tableViewCars;

@property (strong, nonatomic)NSArray *customerCars;

- (IBAction)customerCarBtn:(id)sender;

serviceview.m

@interface ServiceViewController ()

@end

@implementation ServiceViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.tableViewCars.delegate = self;
    self.tableViewCars.dataSource = self;
     _selectionArray = @[@"Car Service", @"Brake Pads", @"Car Battery", @"Alternator",@"Starter Motor",@"Timing Belt",@"Cooling System",@"Clutch Repair",@"Repair-Others"];
    NSString *uType = [[PFUser currentUser] objectForKey:@"email"];

    PFQuery *query = [PFQuery queryWithClassName:@"customerCars"];
    [query whereKey:@"cEmail" containsString:uType];
    NSLog(@"%@",uType);
    [query findObjectsInBackgroundWithBlock:^(NSArray *customerCar, NSError *error) {
        if (customerCar) {
            NSLog(@"Successfully retrieved %lu scores.", (unsigned long)customerCar.count);
            for (PFObject *objects in customerCar) {
                NSLog(@"%@", objects.objectId);
                _customerCars = @[objects];
                self.customerCars = [[NSArray alloc]initWithObjects:@[objects], nil];
               // NSLog(@"%@",[_customerCars.objectId]);
            }
            //NSLog(customerCars);
        }
    }];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{

    return [self.customerCars count];

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{


    static NSString *simpleTableIdentifier = @"SimpleTableItem";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];



    if (cell == nil) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];

    }


    cell.textLabel.text = [self.customerCars objectAtIndex:indexPath.row] ;

    //cell.textLabel.font = [UIFont systemFontOfSize:11.0];


    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{


    UITableViewCell *cell = [self.tableViewCars cellForRowAtIndexPath:indexPath];


    self.tableViewCars.hidden = YES;

}


- (IBAction)customerCarBtn:(id)sender {

    if (self.tableViewCars.hidden == YES) {
        self.tableViewCars.hidden = NO;
    }

    else
        self.tableViewCars.hidden = YES;


}

Answer 1

存储在您的 customerCars 数组中的对象属于 PFObject 类型，因为这是 Parse returns.

为了从汽车的一个 Parse 属性中获取字符串值，请将其作为对象的字典键进行访问。

例如，假设您要更新单元格文本标签以显示汽车的 'colour' 属性。你会使用类似的东西：

PFObject *car = [self.customerCars objectAtIndex:indexPath.row];
cell.textLabel.text = [NSString stringWithFormat: @"%@ - %@", car[@"make"], car[@"model"]];

Answer 2

首先，您必须检查具有字符串格式值的字段的解析。

然后您必须使用 PFQuery 的 selectKeys 方法并在数组中传递 keyNames 以仅从解析中获取选定的键，如下所示：

PFQuery *query = [PFQuery queryWithClassName:@"customerCars"];
[query whereKey:@"cEmail" containsString:uType];
[query selectKeys:@[@"column1",@"column2",@"column3"]];

从解析中获取对象并转换为字符串

getting object from parse into array and converting into strings

objective-c

ios

parse-platform

xcode7