Keeping a UIButton selected after a touch

Greg Maletic picture Greg Maletic · Nov 23, 2009 · Viewed 91.5k times · Source

After my user clicks a button, I'd like that button to stay pushed during the time that I perform a network operation. When the network operation is complete, I want the button to return to its default state.

I've tried calling -[UIButton setSelected:YES] right after the button push (with a corresponding call to -[UIButton setSelected:NO] after my network op finishes) but it doesn't seem to do anything. Same thing if I call setHighlighted:.

I suppose I could try swapping out the background image to denote a selected state for the duration of the network op, but that seems like a hack. Any better suggestions?

Here's what my code looks like:

- (IBAction)checkInButtonPushed
{
    self.checkInButton.enabled = NO;
    self.checkInButton.selected = YES;
    self.checkInButton.highlighted = YES;
    [self.checkInActivityIndicatorView startAnimating];
    [CheckInOperation startWithPlace:self.place delegate:self];
}

- (void)checkInCompletedWithNewFeedItem:(FeedItem*)newFeedItem wasNewPlace:(BOOL)newPlace possibleError:(NSError*)error;
{
    [self.checkInActivityIndicatorView stopAnimating];
    self.checkInButton.enabled = YES;
    self.checkInButton.selected = NO;
    self.checkInButton.highlighted = NO;
}

Answer

Bryan Henry picture Bryan Henry · Nov 23, 2009

How are you setting the images for the different UIControlStates on the button? Are you setting a background image for UIControlStateHighlighted as well as UIControlStateSelected?

UIImage *someImage = [UIImage imageNamed:@"SomeResource.png"];
[button setBackgroundImage:someImage forState:UIControlStateHighlighted];
[button setBackgroundImage:someImage forState:UIControlStateSelected];

If you're setting the selected state on the button touch down event rather than touch up inside, your button will actually be in a highlighted+selected state, so you'll want to set that too.

[button setBackgroundImage:someImage forState:(UIControlStateHighlighted|UIControlStateSelected)];

Edit:

To sum up my remarks in the comments and to address the code you posted...you need to set your background images for the full UIControl state that you're in. According to your code snippet, this control state would be disabled + selected + highlighted for the duration of the network operation. This means that you would need to do this:

[button setBackgroundImage:someImage forState:(UIControlStateDisabled|UIControlStateHighlighted|UIControlStateSelected)];

If you remove the highlighted = YES, then you would need this:

[button setBackgroundImage:someImage forState:(UIControlStateDisabled|UIControlStateSelected)];

Get the picture?