问题
I would like to pass a parameter to a function called as a selector from a timer. Specifically the reference to a cell so i can update something in the UI.
So what I want to something like this:
timer = Timer.init(timeInterval: 1.0, target: self, selector: #selector(downloadTimer(cell: cell), userInfo: nil, repeats: true)
Function
func downloadTimer(cell: InnerCollectionCell) {
cell.progressBar.setProgress(downloadProgress, animated: true)
}
Though I might be a bit niece in assuming this can be done?
------ EDIT ------
As per the below examples, but not getting expected results as usual from a cell
let innerCell: InnerCollectionCell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifierInner, for: indexPath) as! InnerCollectionCell
timer = Timer.init(timeInterval: 1.0, target: self, selector: #selector(downloadTimer(_:)), userInfo: innerCell, repeats: true)
func downloadTimer(_ timer: Timer) {
let cell = timer.userInfo
cell. // no options as expected of a cell
}
I expected more options like this if the data was sent correctly:
回答1:
set your timer with the userinfo
timer = Timer.init(timeInterval: 1.0, target: self, selector: #selector(downloadTimer(cell: cell), userInfo: data, repeats: true)
and get userinfo as follow
func downloadTimer(_ timer: Timer) {
let data = timer.userInfo
}
------ EDIT ------
As per the below examples, but not getting expected results as usual from a cell
let innerCell: InnerCollectionCell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifierInner, for: indexPath) as! InnerCollectionCell
timer = Timer.init(timeInterval: 1.0, target: self, selector: #selector(downloadTimer(_:)), userInfo: innerCell, repeats: true)
func downloadTimer(_ timer: Timer) {
let cell = timer.userInfo as! InnerCollectionCell
cell. // no options as expected of a cell
}
回答2:
You pass in the data you want as the userInfo argument when creating the Timer:
timer = Timer.init(timeInterval: 1.0, target: self, selector: #selector(downloadTimer(_:), userInfo: myData, repeats: true)
and make the callback look like:
func downloadTimer(_ timer: Timer) {
// access timer.userInfo here
}
来源：https://stackoverflow.com/questions/42155837/pass-parameter-to-selector-function-in-swift