ios - UITableView不会显示数据

Question

我有一个 UITableView，它拒绝显示任何数据，Xcode 没有显示任何错误或警告。不知道为什么这是因为相同的代码在不同的应用程序中工作(显然数组和 TableView 的名称不同)。我将委托(delegate)和数据源都设置为 View View Controller 。如果有什么我错过的请告诉我!这是我的代码:

#import "ViewController.h"

@interface UIViewController ()

@end

@implementation ViewController
@synthesize CafeTableView;

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    [self performSelector:@selector(RetriveData)];
    [CafeTableView reloadData];

}

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

- (void)RetriveData {
    PFQuery *query = [PFQuery queryWithClassName:@"CafeList"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            NSLog(@"%@",objects);
            NSLog(@"Successfully retrieved %d Cafes.", objects.count);
            cafeListArry = [[NSArray alloc] initWithArray:objects];

        }else{
            UIAlertView *theAlert = [[UIAlertView alloc] initWithTitle:@"Error"
                                                               message:(@"There has been an error loading the Cafe List Please Try Again!")
                                                              delegate:self
                                                     cancelButtonTitle:@"OK"
                                                     otherButtonTitles:nil];
            [theAlert show];
            NSLog(@"%@",error);
        }
    }];
    [CafeTableView reloadData];
}

//-------------------TABLE VIEW-----------------------

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    return cafeListArry.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"CafeCell";
    CafeListCell *cell = [CafeTableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

    // Configure the cell...

    PFObject *tempObject = [cafeListArry objectAtIndex:indexPath.row];

    cell.title.text = [tempObject objectForKey:@"CafeName"];
    cell.detail.text = [tempObject objectForKey:@"NumberOfStars"];

    return cell;
}


@end

Answer 1

按照其他人的建议，将您的调用移至 block 内的 reloadData 并按如下方式更改 if 条件:

- (void)RetriveData {
    PFQuery *query = [PFQuery queryWithClassName:@"CafeList"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (objects) {
            NSLog(@"%@",objects);
            NSLog(@"Successfully retrieved %d Cafes.", objects.count);
            cafeListArry = [[NSArray alloc] initWithArray:objects];
            [CafeTableView reloadData];  // HERE
        }else{
            UIAlertView *theAlert = [[UIAlertView alloc] initWithTitle:@"Error"
                                                               message:(@"There has been an error loading the Cafe List Please Try Again!")
                                                              delegate:self
                                                     cancelButtonTitle:@"OK"
                                                     otherButtonTitles:nil];
            [theAlert show];
            NSLog(@"%@",error);
        }
    }];
}

此外，按照 Lyndsey 在评论中的建议，更改以下行

cell.detail.text = [tempObject objectForKey:@"NumberOfStars"];

到

cell.detail.text = [[tempObject objectForKey:@"NumberOfStars"] stringValue];

因为你说是数字，不是字符串。