Activity Indicator IOS usage question

Question

First I would like to thank everyone who attempts to help me with my problem, I am new to iOS development, specifically objective-c, so I apologize if my question is extremely obvious.

I am making an app that loads some new data (parsed from a website but it is NOT a UIWebView) into the same current view every time the user changes a selection on the picker view (UIPickerView). The method that inserts this new data into the current view is called -(IBAction) getNewData: (id) sender.

getNewData is called every time the user makes a new selection with the picker. This is how it is called within the picker method and the picker as well as everything else works fine.

- (void)pickerView:(UIPickerView*)pickerView 
      didSelectRow:(NSInteger)row 
       inComponent:(NSInteger)component
{
    NSString *choosen;
    choosen = [currentLottoNames objectAtIndex:row];    
    [self getNewData:choosen];
}

I would like to implement an activity indicator (spinner) for the loading time in-between the time the user makes/changes his selection on the scroller to the time the actual data shows up in the view after the user has made his selection on the scroller. How would I go about implementing this?

Thank you.

score 2 · Answer 1 · answered Sep 29 '11 at 02:13

2

To show the user that you are accessing information via apples built in status bar you use

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;

If you would like to display like a pop up message you need to declare in the header a

 UIAlertView *load_message;

and then when you would like to show the load_message use

load_message = [[UIAlertView alloc] initWithTitle:@"Loading..." message:nil delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
    [load_message show];
    UIActivityIndicatorView *active = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    active.center = CGPointMake(load_message.bounds.size.width / 2, load_message.bounds.size.height - 40);
    [active startAnimating];
    [load_message addSubview:active];

and that will show a pop up displayed to the user that you are loading something. This is for locking up the screen showing the user that you are getting some information.

answered Sep 29 '11 at 02:13

Tony

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Okay I figured out where to put it but unfortunately it leads me back to my original problem. The box is a very nice touch though. So the problem is the loading indicator is coming up when the data is already loaded opposed to immediately when the user chooses a different value with the picker. When a user picks a different value on the picker, there is about a 3 second delay and then the content shows up. In these approx 3 seconds I would like the loding to come up then and not at the same time when the data is actually loaded. Thanks – Teddy13 Sep 29 '11 at 02:33
Ummm. Are you showing the load_message in the pickerDidChange method? Also I will be on the iPhone Developer chat for another 20 minutes if you are on :) – Tony Sep 29 '11 at 03:15
Sorry Tony I was not able to go on.:( What is this pickerDidChange method? I cant seem to find it anywhere, even in the documentation with uipickerview. I feel if this method exists then it is exactly what I may need unless you are referring to the method - (void)pickerView:(UIPickerView*)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component? Thanks again! – Teddy13 Sep 29 '11 at 06:58
Hrmm you are correct. I must be thinking of the UISlider. So my only suggestion then is to add a Gesture recognizer onto the view and listen for the touches ended method so you know that they changed it or maybe the touchesMoved or began. That would add a little bit more flexibility umm. I am not a hundred percent sure what you are looking to do though. Could you maybe rephrase your comment? Here is the gesture recognizer tut http://stackoverflow.com/questions/1049889/how-to-intercept-touches-events-on-a-mkmapview-or-uiwebview-objects – Tony Sep 29 '11 at 18:08

Activity Indicator IOS usage question

1 Answers1