Question

I am developing an application of simple slideshow.

Description : In the application I’ve 5 images stored in an array.Currently I’m displaying the images into a scroll view but I want to show a slideshow of the images stored in the array. how can I do that ? Any tutorials ?

regards

Answer 1

I’d suggest using an NSTimer, here’s some basic code. However the “page” number has to be calculated somewhere, according how you’d like to handle the edge cases, for example: last image in slide show.

Have a look at Apple’s example app PageControl, which shows a nice way how to handle memory efficiently in a paging scrollview.

self.slideTimer = [NSTimer scheduledTimerWithTimeInterval:3.0
                                                   target:self 
                                                 selector:@selector(slide) 
                                                 userInfo:nil 
                                                  repeats:YES];

...

- (void)slide
{
    CGRect frame = scrollView.frame;
    frame.origin.x = frame.size.width * nextImagePageNumber;
    frame.origin.y = 0;
    [scrollView scrollRectToVisible:frame animated:YES];
}

NSTimer

You use the NSTimer class to create
timer objects or, more simply, timers.
A timer waits until a certain time
interval has elapsed and then fires,
sending a specified message to a
target object. For example, you could
create an NSTimer object that sends a
message to a window, telling it to
update itself after a certain time
interval.