TableView不显示来自parse.com的数据

Question

Hi everyone beginner here. I have a table view inside the ViewController. Content of the cell will be taken from parse.com. (A String) I already put necessary frameworks and set up a class in parse with a column and some rows. I can tap the cells in simulator and when i add or delete new rows in parse the cells i can tap also changes. But somehow the table turns empty, no label is displayed. I have no errors or issues. Here is the code:

ViewController.h

#import <UIKit/UIKit.h>
#import <Parse/Parse.h>
#import "TableCell.h"

@interface ViewController : UIViewController <UITableViewDelegate> {

NSArray *Event;
}
@property (weak, nonatomic) IBOutlet UITableView *newsTable;

@end

ViewController.m

#import "ViewController.h"
#import "TableCell.h"

@interface ViewController ()

@end

@implementation ViewController
@synthesize newsTable;


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

}

- (void) retreiveFromParse {
PFQuery *retrieveEvents = [PFQuery queryWithClassName:@"News"];
[retrieveEvents findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
    if (!error) {
        Event = [[NSArray alloc] initWithArray:objects];

}
    [newsTable reloadData];
}];
}

//*********************Setup table of folder names ************************

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

//get number of rows by counting number of folders
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return Event.count;
}

//setup cells in tableView
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath       *)indexPath {

//setup cell
static NSString *CellIdentifier = @"EventCell";
TableCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

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

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

return cell;
}


//user selects folder to add tag to
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"cell tapped");
}



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

@end

Answer 1

Few corrections -

1. First - it will be more appropriate to use a @property for the event array.
2. Second - it will be more appropriate to use Lowercased property name.
3. Your Array is not retained (it is nil), this is why you see nothing.

So, you should :

Add this to your interface -

  @property (strong, nonatomic) NSArray *events;

Add this to your viewDidLoad, before you call retreiveFromParse

 - (void)viewDidLoad
     {
       [super viewDidLoad];
        self.events = [NSArray array];
        // Do any additional setup after loading the view, typically from a nib.
        [self performSelector: @selector(retreiveFromParse)];
      }

That should work.

BTW Parse has a TableViewController class that can simplify your work, look here - Parse PFQueryTableViewController