单元格中的UILabel仅在上下滚动后显示

Question

我在单元格中有一个标签，我想用我解析的JSON数组中的数据更新它。问题是，在获得数据后，标签是空白的，只有在我上下滚动表视图后才会显示。我已经尝试过用[self.view setNeedsDisplay];强制重新加载视图，但它仍然不起作用。我该如何处理？

以下是代码片段，其中包含一些注释：

@implementation outletView
@synthesize outletInfo;
- (void)viewDidLoad
{
    [super viewDidLoad];
    ...
    // Do any additional setup after loading the view.
    [[AFHTTPRequestOperationManager manager] GET:[SERVER_URL stringByAppendingString:@"api/points"] parameters:[NSDictionary dictionaryWithObjectsAndKeys:[[NSUserDefaults standardUserDefaults] objectForKey:@"authToken"],@"auth_token",nil] success:^(AFHTTPRequestOperation *operation, id responseObject) {
        NSString *outletID = [[outletInfo valueForKeyPath:@"preference"] objectForKey:@"outlet_id"];
        NSArray *outletArray = (NSArray*)responseObject;
        NSLog(@"array: %@", outletArray);
        for(NSDictionary *diction in outletArray) {
            NSString *dictionID = [diction objectForKey:@"outlet_id"];
            if ([dictionID isEqualToString:outletID]) {
                pointOutlet = [diction objectForKey:@"total"]; 
            }
        }        
    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
        NSLog(@"Error : %@",[error description]);
    }];
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *CellIdentifier = indexPath.section==0 ? @"outletViewCell" : @"categoryCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    // Here is the cell
    if(indexPath.section==0){
        [cell setSelectionStyle:UITableViewCellSelectionStyleNone];
        [(UIImageView *)[cell viewWithTag:1] sd_setImageWithURL:[NSURL URLWithString:outletInfo[@"backgroundImageUrl"]] placeholderImage:nil];
        [(UIImageView *)[cell viewWithTag:2] sd_setImageWithURL:[NSURL URLWithString:outletInfo[@"logoUrl"]] placeholderImage:nil];
        [(UILabel *)[cell viewWithTag:3] setText:outletInfo[@"name"]];
        [(UILabel *)[cell viewWithTag:4] setText:outletInfo[@"address"]];
        //Here is the UILabel that I want to update
        [(UILabel *)[cell viewWithTag:6] setText:pointOutlet];
    } else {
       ...
    }
    return cell;
}
@end

Answer 1

执行以下更改：-

 [[AFHTTPRequestOperationManager manager] GET:[SERVER_URL stringByAppendingString:@"api/points"] parameters:[NSDictionary dictionaryWithObjectsAndKeys:[[NSUserDefaults standardUserDefaults] objectForKey:@"authToken"],@"auth_token",nil] success:^(AFHTTPRequestOperation *operation, id responseObject) {
    NSString *outletID = [[outletInfo valueForKeyPath:@"preference"] objectForKey:@"outlet_id"];
    NSArray *outletArray = (NSArray*)responseObject;
    NSLog(@"array: %@", outletArray);
    for(NSDictionary *diction in outletArray) {
        NSString *dictionID = [diction objectForKey:@"outlet_id"];
        if ([dictionID isEqualToString:outletID]) {
            pointOutlet = [diction objectForKey:@"total"]; 
        }
     }
       //Here you need to call tableView reload. This will reload your tableView and show the label.
      [tableView reload];       
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
    NSLog(@"Error : %@",[error description]);
}];

Answer 2

解析响应时，在主线程上重新加载表。

 dispatch_async(dispatch_get_main_queue(), ^{
    });

重新加载此块中的表。

Answer 3

当数据没有到来，并且您的tableView方法之前调用，从服务器获取所有数据后重新加载表视图时，就会出现这种问题。