UITableViewCell subclass with UIImageView proper way to reuse - ios

Question

I have a UITableViewCell subclass. I want to add a UIImageView as a subview, but make sure to do proper reuse so that I am not adding the subview over and over. I also want to make sure to nil out the image in prepareForReuse.
What is the proper method for doing this?

Answer 1

In your custom cell subclass you should add any required views in the initWithStyle:reuseIdentifier: method. As long as you have registered your cell class against the reuse identifier in your table view then this initialiser will be called by dequeueReusableCellWithIdentifier:forIndexPath: whenever a new cell is required. This method will not be called when a cell is reused, so your image view won't be added more than once.
You can clear the image view's current image in the cell class's prepareForReuse method.

Answer 2

For proper reuse of cell, register cell xib in viewDidLoad in UIViewController class and then write
CustomCell *cell = [tableView dequeueReusableCellWithIdentifier:#"cell_ID"];
and then load image in imageView inn cell.This guarantees reuse of cell.

Answer 3

You need to add the UIImageView as a property of the UITableviewCell subclass. That way in cellForRowAtIndexPath you just say myCellInstance.profilePicView.image = ...
Have a look at my answer here on how I added textfields as cell subviews. Look specifically at the override for initWithStyle:reusableIdentifier: in the PersonCell class. No use of prototype cells in storyboard, no use of viewWithTag, just as you want.
Here is what the cellForRowAtIndexPath would look like if the Person class had a profile pic :
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
PersonCell *cell = nil;
cell = [tableView dequeueReusableCellWithIdentifier: #"CellWithNameAndSurname"];
if(!cell)
{
cell = [[PersonCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"CellWithNameAndSurname"];
cell.contentView.backgroundColor = [[UIColor blueColor] colorWithAlphaComponent: 0.08f];
cell.delegate = self;
}
//this should be outside the above if statement!
Person *respectivePerson = _peopleArray[indexPath.row];
cell.profilePicView.image = respectivePerson.profilePic;
cell.nameTextField.text = respectivePerson.name;
cell.surnameTextField.text = respectivePerson.surname;
cell.positionLabel.text = [NSString stringWithFormat:#"%i", (int)indexPath.row];
return cell;
}

Answer 4

Proper way to clean cell before reuse is
-(void)prepareForReuse;
just set self.imageView.image = nil;
And to create UIImageView , I'd do something like that:
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
[self setup];
return self;
}
- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
[self setup];
return self;
}
- (void)setup {
/// Create your UIImageView and set layout
}