在后台运行完成后,如何使用parse.com查询中的数据填充UITableView？

Question

我有一个UITableViewController负责显示满员的桌子.此数据存储在parse.com上的数据库中.

这是我的UITableViewController,我刚开始商店:

-(id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{
    self = [super initWithNibName:nil bundle:nil];
    if(self){
        store = [[EmployeeStore alloc] init]; 
    }
    return self;
}

这是EmployeeStoreinit方法,我在其中查询员工:

-(id) init{
    self = [super init];
    if(self){
        employees = [[NSMutableArray alloc] init];
        [self fetchEmployeesFromDatabase];
    }
    return self;
}

fetchEmployeesFromDatabase,我在那里查询员工.

-(void) fetchEmployeesFromDatabase{
    PFQuery *query = [PFQuery queryWithClassName:@"Employee"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            // The find succeeded.
            NSLog(@"Successfully retrieved %d scores.", objects.count);
            // Do something with the found objects
            for (PFObject *object in objects) {
                NSLog(@"%@", object.objectId);
                [employees addObject:object]; 
            }
        } else {
            // Log details of the failure
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
    }];
}

我成功地接收了它们,但是问题是查询发生在后台,并且直到表视图加载完成后才完成,因此表视图不会填充.我需要让表在查询完成后重新加载其数据,但我该怎么做呢？

Answer 1

的UITableViewController

-(id) initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{
    self = [super initWithNibName:nil bundle:nil];
    if(self){
        store = [[EmployeeStore alloc] init];
        store.tableView = self.tableView; 
    }
    return self;
}

EmployeeStore.h

@property (nonatomic, strong) UITableView *tableView;

EmployeeStore.m

-(id) init{
    self = [super init];
    if(self){
        employees = [[NSMutableArray alloc] init];
        [self fetchEmployeesFromDatabase];
    }
    return self;
}

和fetchEmployeesFromDatabase

-(void) fetchEmployeesFromDatabase{
    PFQuery *query = [PFQuery queryWithClassName:@"Employee"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            // The find succeeded.
            NSLog(@"Successfully retrieved %d scores.", objects.count);
            // Do something with the found objects
            for (PFObject *object in objects) {
                NSLog(@"%@", object.objectId);
                [employees addObject:object]; 
            }

             dispatch_async(dispatch_get_main_queue(), ^ {
                [self.tableView reloadData];
              });

        } else {
            // Log details of the failure
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
    }];
}