why init method in cell won't get called when dequeueReusableCellWithIdentifier happened - ios

Question

my code look like this
viewcontroller.m
- (void)viewDidLoad {
[super viewDidLoad];
UITableView *tableView = [[UITableView alloc] init];
tableView.delegate = self;
tableView.dataSource = self;
[tableView registerClass:[TableViewCell class] forCellReuseIdentifier:#"cell"];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
TableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell" forIndexPath:indexPath];
cell.textLabel.text = #"Hello, world";
cell.delegate = self;
return cell;
}
cell.m
- (void)awakeFromNib {
[super awakeFromNib];
[self commonInit];
// Initialization code
}
- (instancetype)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self commonInit];
}
return self;
}
- (void)commonInit
{
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPress)];
[self addGestureRecognizer:longPress];
}
- (void)longPress
{
[self.delegate actionTriggered:self];
}
so screen shows a tableview with only one cell contains "hello world"
when use long press gesture nothing happened.
so I set a break point in commonInit.
find out this method does not get called.
can't figure out why. and how to fix it.
appreciating any helps.

Answer 1

In 'viewDidLoad' you create a local variable 'tableView'. That variable gets out-of-scope as soon as the method completes.
This can't work.
Assuming the class in your viewcontroller.m file inherits from UITableViewController you just have to make sure you configure the existing tableView property instead of creating a local variable:
-(void)viewDidLoad {
[super viewDidLoad];
// UITableView *tableView = [[UITableView alloc] init]; <-- Don't!
tableView.delegate = self;
tableView.dataSource = self;
[tableView registerClass:[TableViewCell class] forCellReuseIdentifier:#"cell"];
}