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iosnslog

iOS - how to NSLog just one time when using scrollViewDidScroll

In the method - (void)scrollViewDidScroll:(UIScrollView *)sender I tried to NSLogan integer and it NSLog the integer more than one time when I scroll.

Is there's any way to NSLog the integer just one time?

Solution

  • Use the UIScrollViewDelegate method scrollViewWillBeginDragging: to get only when the scroll starts. It is not called constantly like scrollViewDidScroll: is.

    Here are the other UIScrollViewDelegate methods if you are interested:

    – scrollViewDidScroll:
– scrollViewWillBeginDragging:
– scrollViewWillEndDragging:withVelocity:targetContentOffset:
– scrollViewDidEndDragging:willDecelerate:
– scrollViewShouldScrollToTop:
– scrollViewDidScrollToTop:
– scrollViewWillBeginDecelerating:
– scrollViewDidEndDecelerating:

    Source: https://developer.apple.com/library/ios/documentation/uikit/reference/uiscrollviewdelegate_protocol/reference/uiscrollviewdelegate.html#//apple_ref/occ/intfm/UIScrollViewDelegate/scrollViewWillBeginDragging: