I have a retain cycle when defining a closure as a variable.
The variable is defined as below:
public class MyCell: UICollectionViewCell {
public var callback: ((MyCell)->Void)?
}
If I use delegates instead of closures, the retain cycle disappears, but I would like to know how can it be defined with closures for future cases.
I tried to set callback variable as weak
, but, as I suppose, weak attribute can only be applied to class and class-bound protocol types.
EDIT
Usage:
class CustomController: UIViewController {
private func onActionOccurs(_ cell: MyCell) {
cell.backgroundColor = .red // For example
}
// After dequeuing the cell:
{
cell.callback = onActionOccurs(_:)
}
}
Thanks
If you don't need to use self, then you can use the cell itself, and modifying your closure implementation in cell like this
public class MyCell: UICollectionViewCell {
public var callback: (()->Void)?
}
then you can use it, like this example
class CustomController: UIViewController {
private func onActionOccurs(_ cell: MyCell) {
cell.backgroundColor = .red // For example
}
// After dequeuing the cell:
{
cell.callback = {
cell.backgroundColor = .red // For example
}
}
}
but if you need to use a ViewController method then you need to use the [weak self]
capture list If you need use UIViewController methods
class CustomController: UIViewController {
private func onActionOccurs(_ cell: MyCell) {
cell.backgroundColor = .red // For example
}
// After dequeuing the cell:
{
cell.callback = { [weak self] in
guard self != nil else {
return
}
self!.viewControllerMethod()
}
}
}
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