UITableView cellForRowAtIndexPath未被调用

尝试做以下事情

1.)注册你的tableView

[_tableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"SimpleTableItem"];

2.)然后[_tableView reloadData]; 在下面添加

for (PFObject *object in objects) {
        NSLog(@"%@", object.objectId);
        tableData[countUsers] = [object valueForKey:@"username"];
        matchesForUser[countUsers] = [object valueForKey:@"matches"];
    }

内部if (!error)..

所以你的更新代码必须如此

[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
    for (PFObject *object in objects) {
        NSLog(@"%@", object.objectId);
        tableData[countUsers] = [object valueForKey:@"username"];
        matchesForUser[countUsers] = [object valueForKey:@"matches"];
    }
    [_tableView reloadData];
}else{
    NSLog([error description]);
}

NSLog(@"***tabledata***");
NSLog([NSString stringWithFormat:@"%lu", (unsigned long)[tableData count]]);
NSLog(@"***matchesdata***");
NSLog([NSString stringWithFormat:@"%lu", (unsigned long)[matchesForUser count]]);
}];