Why UIRefreshControl jumping?

问题:

I try to use the UIRefreshControl with swift 1.2 and works fine except the UI. It is jumping and I dont know why. Here is what I am doing:

class ViewController: UIViewController {

     var refreshControl:UIRefreshControl!

    @IBOutlet weak var tableView: UITableView!
    override func viewDidLoad() {
        super.viewDidLoad()

        self.refreshControl = UIRefreshControl()
        self.refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
        self.refreshControl.addTarget(self, action: "refresh:", forControlEvents: UIControlEvents.ValueChanged)
        self.tableView.addSubview(refreshControl)
    }

    func refresh(sender:AnyObject) {
        // Code to refresh table view
    }

}

And you can download my poc project from here: POC project

While you pull down the tableView, suddenly jump a little bit down. Has anybody any idea why?

If I use with UITableViewController, It works fine but I dont want to use this UI object. I would like to use a simple UITableView in a UIViewController.

回答1:

I found a solution, it works:

override func viewDidLoad() {
    super.viewDidLoad()

    self.refreshControl = UIRefreshControl()
    self.refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
    self.refreshControl.addTarget(self, action: "refresh:", forControlEvents: UIControlEvents.ValueChanged)


    var tableViewC = UITableViewController()
    tableViewC.refreshControl = self.refreshControl

    self.tableView = tableViewC.tableView

    self.view.addSubview(self.tableView)
}

回答2:

I have experienced this problem and I believe it is because the UIRefreshControl was meant for UITableViewController.

I think you should try to insert the view at index 0 like below. (Excuse the objective-c)

[self.tableView insertSubview:_refreshControl atIndex:0];

Edit

Do you have code to stop the refreshControl?

    // End Refreshing
    if ([self.refreshControl isRefreshing]) {
        float delayInSeconds = 1.0;

        dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
        dispatch_after(popTime, dispatch_get_main_queue(), ^{
            [self.refreshControl endRefreshing];

        });
    }

回答3:

For Xamarin.iOS it's looks like this:

[Register ("MyViewController")]
partial class MyViewController
{
    [Outlet]
    public UITableView myTableView { get; set; }

    // ...
}

public partial class MyViewController : UIViewController
{
    public UIRefreshControl myRefreshControl { get; set; }

    public override void ViewDidLoad()
    {
        base.ViewDidLoad();

        // ...

        this.myRefreshControl = new UIRefreshControl();
        this.myRefreshControl.AttributedTitle = new NSAttributedString("Load News from server...");
        this.myRefreshControl.AddTarget(this, new ObjCRuntime.Selector("RefreshSource"), UIControlEvent.ValueChanged);

        #region Fix the Jump problem
        UITableViewController tableViewController = new UITableViewController();
        tableViewController.TableView = this.myTableView;
        tableViewController.RefreshControl = this.myRefreshControl;
        #endregion

        #region Fix the unwanted first showing
        this.myRefreshControl.BeginRefreshing();
        this.myRefreshControl.EndRefreshing();
        #endregion

        // ...
    }

    [Export("RefreshSource")]
    private async void RefreshSource()
    {
        #region Edit source data
        await Task.Run(() =>
            {
                Thread.Sleep(3000);
            });
        #endregion

        this.myTableView.ReloadData();
        this.myRefreshControl.EndRefreshing();
    }
}

回答4:

Try this One will working good

var tableViewController = UITableViewController(style: UITableViewStyle.Plain)
tableViewController.tableView = self.myTableView

self.refreshControl = UIRefreshControl()
self.refreshControl.addTarget(self, action: #selector(self.getConnections),forControlEvents: .ValueChanged)
tableViewController.refreshControl = self.refreshControl