如何以特定速度自动滚动UIScrollView？ [英] How do i make a UIScrollView scroll automatically at a certain speed?

问题描述

我正在使用touchesBegan和touchesMoved来跟踪用户的互动，因此我可以看到用户触摸屏幕的位置。我想要做的是当他们将手指移动到屏幕的最后20个像素时，让UIScrollView scroll1向下滚动。但是我如何定义速度？肯定会有一段时间声明会过快地执行它，并且UIView动画会将它移动到某个地方但只有一次。

I am using touchesBegan and touchesMoved to track a user's interaction, so I can see where the user has touched the screen. What I want to do is when they take their finger to the last 20 pixels of the screen, have the UIScrollView scroll1 to scroll down. But how do i define a speed? Surely a while statement would do it far too rapidly, and a UIView animation would move it to a certain place but only the once.

推荐答案

您可以通过以下代码执行此操作：

You can do this by the following code :

[UIScrollView beginAnimations:@"scrollAnimation" context:nil];

[UIScrollView setAnimationDuration:REQUIRED_ANIMATION_DURATION];

[scroll setContentOffset:CGPointMake(REQUIRED_DISTANCE_X, REQUIRED_DISTANCE_Y)];

[UIScrollView commitAnimations];

只需将REQUIRED_ANIMATION_DURATION的值设置为您想要的任何时间间隔。较小的时间间隔意味着更快的速度。

Just set the values of REQUIRED_ANIMATION_DURATION to whatever time interval you want. A smaller time interval will mean faster speed.

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