segue不使用UITableViewCell alloc，但是dequeueReusableCellWithIdentifier

Question

I'm using storyboard with UITableView in UINavigationController. In this UITableView, used custom tableViewCell having interior properties.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    CustomTableViewCell *cell = nil;

    if (SYSTEM_VERSION_LESS_THAN(@"6.0") ) {

        //iOS 6.0 below
        cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"];
    }
    else {
        //iOS 6.0 above

        cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath]; //work segue

    }

Above code work well with push segue. But not when I used

     cell = [[CustomTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];   //not work segue

I used this alloc method for preserve cell's data from reusing cell.

It's just alloc vs deque.. method difference. What am I missing?

edit) I know that not using the dequeReusableCell method is bad for the performance reason. But, the number of cells would not be many. This is why I don't need the deque method.

1. "not working" means "do not perform push segue", not crash.

   It shows cell same like when dequeReusable method used except the disclosure indicator icon at the right of cell. The indicator icon come from storyboard setting.

   And when I touch the cell, the cell highlighted blue but the push segue does not performed.

2. CustomTableViewCell has 4 properties. That's all different from UITableViewCell. Users set the properties at DetailViewController(push segue lead to this). The cell doesn't have IBOutlet ref. In MasterViewController(having the tableView), cellForRowAtIndexPath method returns CustomTableViewCell above code.

3. cellForRowAtIndexPath method adds a on/off button on the left of indicator on CustomTableViewCell And set a tag number for the cell.

Answer 1

The use of dequeueReusableCellWithIdentifier is what enables you to use your prototype cell. If you use initWithStyle instead of dequeueReusableCellWithIdentifier , then you don't and you therefore lose any segues, disclosure indicators, other UI appearance that you've defined for those cell prototypes, too.

If you're determined to go this route, you'll have to go "old school" (ie do what we all used to do before cell prototypes) and write your own didSelectRowForIndexPath . But if you already have that segue defined, let's say you called it "SelectRow", then your didSelectRowForIndexPath can perform that:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

    [self performSegueWithIdentifier:@"SelectRow" sender:cell];
}

If you need to have your disclosure indicator, then your custom cell routine (or the cellForRowAtIndexPath ) will have to set that manually. And if you add it with

cell.accessoryType = UITableViewCellAccessoryDetailDisclosureButton;

Then you need to manually handle it:

- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

    [self performSegueWithIdentifier:@"SelectAccessory" sender:cell];
}

Bottom line, you can get this to work, but you're just doing a lot of extra work and losing losing the performance and memory benefits of dequeuing cells. I'd heartily encourage you to revisit the decision to not use dequeueCellWithIdentifier .