测量平滑滚动性能

如果有滚动委托,则可以实现该方法 scrollViewDidScroll: . 明确地:

//header:
@interface MyClass : NSObject <UIScrollViewDelegate> {
    CFAbsoluteTime last;
    int updateCount;
    CFTimeInterval timeTotal;
}
@end

//implementation:
@implementation MyClass

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CFAbsoluteTime time = CFAbsoluteTimeGetCurrent();
    if (last > 0) {
        timeTotal += time - last;
        ++updateCount;
        if (timeTotal > 1) {
            NSLog(@"Updates Per Second: %.2f", updateCount / timeTotal);
            updateCount = 0;
            timeTotal = 0;
        }
    }
    last = time;
}

@end

像那样。它未经测试,因此日志记录可能不正确。但要使用它,只需将您的代表分配给 scrollview.delegate 财产。