Pass parameter to selector function in Swift [dupl

问题:

This question already has answers here:

Passing parameters to the method called by a NSTimer (6 answers)

Closed 3 years ago.

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
}