表格视图以编程方式滚动到顶部后，UIRefreshControl 不会消失

Question

When i want to the update data source of the tableview, firstly i want to scroll to top (to header view) then show the UIRefreshControl view, after data source updated then i want to hide the UIRefreshControll.

To do that i tried following line:

self.kisilerTable.scrollRectToVisible(CGRect(x: 0, y: 0, width: 1, height: 1), animated: false)
self.kisilerTable.setContentOffset(CGPoint(x: 0, y: self.kisilerTable.contentOffset.y - (self.refreshControl.frame.size.height)), animated: true)
self.kisilerTable.refreshControl?.beginRefreshing()

Above code is scrolling to top then it shows the UIRefreshControl. And after my data updated i tried to hide it with following code:

self.kisilerTable.reloadData()
DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
    self.kisilerTable.refreshControl?.endRefreshing()
}

But the problem is, above code is hiding the indicator animation but it leaves a space there. As you can see in the screenshot:

If i try to hide with following code:

DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
    self.kisilerTable.reloadData()
    self.kisilerTable.refreshControl?.endRefreshing()
}

It is hiding but, i am losing the hide animation. I don't want to lose hide animation.

How can i resolve this problem?

Answer 1

I think it happens, because in the beginning you use setContentOffset to leave a space, but that space is not removed.

I will suggest another implementation, which works very well:

First you declare the refreshControll before the method viewDidLoad() :

 let refreshControl = UIRefreshControl()

Now do you need create a method for stop the animation when needed:

func stopAnimatingRefreshControl() {
    if let refreshControl = 
       tableView.subviews.first(where: { $0 is UIRefreshControl})as? UIRefreshControl,
       refreshControl.isRefreshing {

        refreshControl.endRefreshing()
    }
}

Now you create an @objc function that be called when scrolls the table to update, normally in this moment you call methods that make your server request to update data.

When this data is updated, you call the function stopAnimatingRefreshControl():

@objc func refreshMyData() {
    // call methods for get data from server
    getDataFromServer()
}

func getDataFromServer() {
   // request completed and data is updated, now i need stop the loading.

    DispatchQueue.main.async {
        self.tableView.reloadData()
    }

    stopAnimatingRefreshControl()
}

Finally, after creating the necessary methods, you need to link our @objc function to refreshControll and our tableView , do it in method viewDidLoad() :

refreshControl.addTarget(self, action: #selector(refreshMyData), for: .valueChanged)
tableView.addSubview(refreshControl)

Now you're done, I hope I helped.