UIRefreshControl incorrect title offset during fir

问题:

The text is offset wrong by the first launch of UIRefreshControl... later sometimes the refresh text doesn't show up at all and just the spiny is visible

I don't think i had this issue with iOS6... might be related to iOS7

Is in a UITableViewController added as a child to a VC, which resides in a modal presented UINavigationController

- (void)viewDidLoad {

    [super viewDidLoad];

    [self setRefreshControlText:@"Getting registration data"];
    [self.refreshControl beginRefreshing];
}

- (void)setRefreshControlText:(NSString *)text {

    UIFont * font = [UIFont fontWithName:@"Helvetica-Light" size:10.0];
    NSDictionary *attributes = @{NSFontAttributeName:font, NSForegroundColorAttributeName : [UIColor blackColor]};
    self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:text attributes:attributes];

}

回答1:

This is definitely an iOS 7 bug, but I haven't figured out exactly what caused it. It appears to have something to do with the view hierarchy — adding my UITableViewController as a child view to a wrapper view controller appeared to fix it for me at first, although the bug is back since iOS 7 GM.

It looks like adding the following code to your UITableViewController after creating the refresh view fixes the positioning issue for good:

dispatch_async(dispatch_get_main_queue(), ^{
    [self.refreshControl beginRefreshing];
    [self.refreshControl endRefreshing];
});

回答2:

calling endRefreshing under viewWillAppear did it for me:

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    [self.refreshControl endRefreshing];
}

Under iOS7 with a custom UITableViewController inside a UINavigationController

回答3:

I had the same problem and for me it worked with layoutIfNeeded after setting the attributedTitle:

- (void)setRefreshControlText:(NSString *)text
{
    UIColor *fg = [UIColor colorWithWhite:0.4 alpha:1.0];
    NSDictionary *attrsDictionary = @{NSForegroundColorAttributeName: fg};
    self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:text attributes:attrsDictionary];
    [self.refreshControl layoutIfNeeded];
}

Cédric suggested to use [self.refreshControl setNeedsLayout], but this does not force an immediate update of the view, so you must use layoutIfNeeded.

回答4:

I finally found the holy grail on this, which looks working in all cases

note : UIRefreshControl is added to a UITableViewController (note, never add UIRefreshControl just as subview to a normal UIVIewController's UITableView) (best to add UITableViewController as a child VC inside a UIViewController if you must)

note : that this also fixes the problem, that the UIRefreshControl is not vissible at first refresh (link)

Add to you .h

@interface MyViewController ()

@property (nonatomic, assign) BOOL refreshControlFixApplied;

- (void)beginRefreshing;
- (void)beginRefreshingWithText:(NSString *)text;
- (void)endRefreshing;
- (void)endRefreshingWithText:(NSString *)text;

@end

Add to you .m

////////////////////////////////////////////////////////////////////////
#pragma mark - UIRefreshControl Fix ([e-mail]) https://stackoverflow.com/questions/19121276/uirefreshcontrol-incorrect-title-offset-during-first-run-and-sometimes-title-mis/
////////////////////////////////////////////////////////////////////////

- (void)beginRefreshingWithText:(NSString *)text {

    [self setRefreshControlText:text];
    [self beginRefreshing];

}

- (void)endRefreshingWithText:(NSString *)text {

    [self setRefreshControlText:text];
    [self.refreshControl endRefreshing];

}

- (void)beginRefreshing {

    if (self.refreshControl == nil) {
        return;
    }

    if (!self.refreshControlFixApplied) {

        dispatch_async(dispatch_get_main_queue(), ^{

            if ([self.refreshControl.attributedTitle length] == 0) {
                [self setRefreshControlText:@" "];
            }
            [self.refreshControl beginRefreshing];

            dispatch_async(dispatch_get_main_queue(), ^{

                [self.refreshControl endRefreshing];

                dispatch_async(dispatch_get_main_queue(), ^{

                    // set the title before calling beginRefreshing
                    if ([self.refreshControl.attributedTitle length] == 0) {
                        [self setRefreshControlText:@" "];
                    }
                    if (self.tableView.contentOffset.y == 0) {
                        self.tableView.contentOffset = CGPointMake(0, -self.refreshControl.frame.size.height);
                    }
                    [self.refreshControl beginRefreshing];

                    self.refreshControlFixApplied = YES;

                });

            });

        });

    } else {

        if (self.tableView.contentOffset.y == 0) {
            self.tableView.contentOffset = CGPointMake(0, -self.refreshControl.frame.size.height);
        }
        [self.refreshControl beginRefreshing];

    }

}

- (void)endRefreshing {

    if (self.refreshControl == nil) {
        return;
    }

    if (!self.refreshControlFixApplied) {
        dispatch_async(dispatch_get_main_queue(), ^{
            [self endRefreshing];
        });
    } else {
        if (self.tableView.contentOffset.y < 0) {
            self.tableView.contentOffset = CGPointMake(0, 0);
        }
        [self.refreshControl endRefreshing];

    }

}

- (void)setRefreshControlText:(NSString *)text {

    UIFont * font = [UIFont fontWithName:@"Helvetica-Light" size:10.0];
    NSDictionary *attributes = @{NSFontAttributeName : font, NSForegroundColorAttributeName : [UIColor colorWithHex:0x00B92E]};
    self.refreshControl.attributedTitle = [[NSAttributedString alloc] initWithString:text attributes:attributes];

}

Use only methods

- (void)beginRefreshing;
- (void)beginRefreshingWithText:(NSString *)text;
- (void)endRefreshing;
- (void)endRefreshingWithText:(NSString *)text;

回答5:

UIRefreshControl seems to still be broken on IOS9.3 when you change the attributedTitle while the tableView is pulled down. What seems to work is to subclass UIRefreshControl and force update its layout once the (attributed) title is changed. The core fix is to trigger a change to the tableView contentOffset (causing some hidden magic in the _update method which layouts the spinner and text subviews) and additionally forcing the frame height to its expected value ensuring the background color fills up the pulled down region.

@implementation MEIRefreshControl
{
    __weak UITableView* _tableView;
}

- (instancetype)initWithTableView:(UITableView*)tableView
{
    self = [super initWithFrame:CGRectZero];
    if (self)
    {
        _tableView = tableView;
    }

    return self;
}

@synthesize title = _title;

- (void)setTitle:(NSString *)title
{
    if (!PWEqualObjects(_title, title))
    {
        _title = title;
        self.attributedTitle = [[NSAttributedString alloc] initWithString:_title ? _title : @""];

        [self forceUpdateLayout];
    }
}

- (void)forceUpdateLayout
{
    CGPoint contentOffset = _tableView.contentOffset;
    _tableView.contentOffset = CGPointZero;
    _tableView.contentOffset = contentOffset;
    CGRect frame = self.frame;
    frame.size.height = -contentOffset.y;
    self.frame = frame;
}

@end

回答6:

This is the code that seems to fix all the issues. Many of the others that involved beginning or ending refreshing where interfering with other parts of the control.

//This chunk of code is needed to fix an iOS 7 bug with UIRefreshControls
static BOOL refreshLoadedOnce = NO;
if (!refreshLoadedOnce) {
  __weak typeof(self) weakself = self;
  [UIView animateWithDuration:0.25 delay:0 options:UIViewAnimationOptionBeginFromCurrentState animations:^(void){
    self.tableView.contentOffset = CGPointMake(0, -weakself.refreshControl.frame.size.height);
  } completion:^(BOOL finished) {
    weakself.refreshControl.attributedTitle = self.refreshControl.attributedTitle;
    [weakself.refreshControl setNeedsUpdateConstraints];
    [weakself.refreshControl setNeedsLayout];
    refreshLoadedOnce = YES;
  }];
}
//End of bug fix

回答7:

I had the same problem, I did solve it by setting attributed text with space string to refresh control directly after init refresh control

_refreshControl = [[UIRefreshControl alloc]init];
[_refreshControl setAttributedTitle:[[NSAttributedString alloc]initWithString:@" "]];

After that, setting new attributed text to refresh control was without any problems.

[[self refreshControl] setAttributedTitle:[[NSAttributedString alloc]initWithString:[NSString stringWithFormat:@"Последнее обновление: %@", [dateFormat stringFromDate:[_post dateUpdated]]]]];

UPDATE

I noticed that problem come back when I use attrsDictionary:

this code works fine

NSAttributedString* attributedString = [[NSAttributedString alloc]initWithString:string];
[[self refreshControl] setAttributedTitle: attributedString];

and this make refreshControl's title appear directly after view loaded

NSAttributedString* attributedString = [[NSAttributedString alloc]initWithString:string attributes:attrsDictionary];
[[self refreshControl] setAttributedTitle: attributedString];

I didn't find solution yet.

UPDATE

Finally found solution, after refreshcontrol init set attributed string also with attributes:attrsDictionary

NSDictionary *attrsDictionary = [NSDictionary dictionaryWithObjects:
                                 [NSArray arrayWithObjects:[UIColor appDarkGray], [UIFont fontWithName:@"OpenSans-CondensedLight" size:14.0f], nil] forKeys:
                                 [NSArray arrayWithObjects:NSForegroundColorAttributeName, NSFontAttributeName, nil]];
[_refreshControl setAttributedTitle:[[NSAttributedString alloc]initWithString:@" " attributes:attrsDictionary]];

so after that there is no problem to set new refreshcontrol's title.

回答8:

The solution for me was to set a text in viewDidAppear, no need to call

beginRefreshing or endRefreshing on the mainQueue

-(void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"d MMM, HH:mm"];
    NSString *lastUpdated = [NSString stringWithFormat:NSLocalizedString(@"refresh_last_updated", nil),[formatter stringFromDate:[NSDate dateWithTimeIntervalSince1970:[[[DatabaseController sharedInstance] getCurrentSettings].lastTimeStamp doubleValue]]]];
    UIFont *font = [UIFont fontWithName:FONT_LATO_LIGHT size:12.0f];
    NSAttributedString *attrString = [[NSAttributedString alloc] initWithString:lastUpdated attributes:@{NSFontAttributeName:font}];

    _refreshControl.attributedTitle = attrString;
}