如何连续旋转UIButton并能停止它？ [英] How can I rotate a UIButton continuously and be able to stop it?

问题描述

我想连续旋转UIButton来表示应用程式正在录音。这是一个好主意。

我如何使用动画来做这个？

解决方案

使用UIView动画方法：

  animateWithDuration：delay：options：animations：completion ：
  

并使用选项 UIViewAnimationOptionRepeat p>

例如对于 UIButton * 出口命名为按钮：

   - （void）viewDidLoad 
 {
 [super viewDidLoad]; 
 [UIView animateWithDuration：2.0 delay：0.0 options：UIViewAnimationOptionRepeat | UIViewAnimationOptionCurveLinear animations：^ {
 CGAffineTransform transform = CGAffineTransformMakeRotation（M_PI）; 
 self.button.transform = transform; 
} completion：NULL]; 
} 
  

因为它是圆的和圆的，我只是旋转它的π弧度， 2pi。

要停止动画，您可以使用任何角度。

，只需创建从当前状态开始的短暂持续时间的动画，例如

   - （void）stopRotating {
 [UIView animateWithDuration：0.1 delay：0.0 options：UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear animations：^ {
 CGAffineTransform transform = CGAffineTransformMakeRotation（M_PI * 0.05）; 
 self.button.transform = transform; 
} completion：NULL]; 
} 
  

这提供了一个非常短的动画，覆盖当前动画。注意，变换的角度乘以0.05，这是0.1 / 2.0的比率，这意味着该小段的旋转速度与连续旋转速度相同。

I want to rotate a UIButton continuously as a means of indicating that an app is recording something. Is this a good idea. I also want to be able to stop this continuous rotation.

How would I use animation to do this?

解决方案

Use the UIView animation method:

animateWithDuration:delay:options:animations:completion:

and use the option UIViewAnimationOptionRepeat

For example for a UIButton * outlet named button:

- (void)viewDidLoad
{
    [super viewDidLoad];
    [UIView animateWithDuration:2.0 delay:0.0 options:UIViewAnimationOptionRepeat | UIViewAnimationOptionCurveLinear animations:^{
        CGAffineTransform transform = CGAffineTransformMakeRotation(M_PI);
        self.button.transform = transform;
    } completion:NULL];
}

Since it's going round and round, I just rotate it by pi radians rather than 2pi. you could use any angle you want.

Edit

To stop the animation, just create another animation of a short duration beginning from the current state, e.g.

- (void)stopRotating {
    [UIView animateWithDuration:0.1 delay:0.0 options:UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionCurveLinear animations:^{
        CGAffineTransform transform = CGAffineTransformMakeRotation(M_PI * 0.05);
        self.button.transform = transform;
    } completion:NULL];
}

This provides a very short animation which overrides the current animation. Note that the angle of the transform is multiplied by 0.05 which is the ratio of 0.1/2.0 which means that the rotational speed for this little segment is the same as the continuous rotational speed.

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