在屏幕上随机移动对象 [英] Moving an object randomly around the screen

问题描述

我正在尝试动画UIButton以在不同方向上随机移动屏幕。下面的代码很有用。该按钮将开始沿着随机路径移动，然而，它继续在A点和B点之间来回移动。

I'm trying to animate a UIButton to move randomly around the screen in different directions. The code below is kind of working. The button will begin moving along a random path, however, it then just continues to move back and forth between point A and point B.

[UIView beginAnimations:nil context:nil]; 
[UIView setAnimationDuration:1]; 
[UIView setAnimationRepeatCount:1000]; 
[UIView setAnimationRepeatAutoreverses:YES]; 

CGFloat x = (CGFloat) (arc4random() % (int) self.view.bounds.size.width); 
CGFloat y = (CGFloat) (arc4random() % (int) self.view.bounds.size.height); 

CGPoint squarePostion = CGPointMake(x, y); 
button.center = squarePostion; 

[UIView commitAnimations];

我怎样才能让它在每次改变方向时继续移动到新的随机点，而不是只是来回移动？

How can I get it to keep moving to a new random point every time it changes directions, instead of simply moving back and forth?

谢谢！

推荐答案

试试这个：

    -(void)animationLoop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context { 

        [UIView beginAnimations:nil context:nil]; 
        [UIView setAnimationDuration:1]; 
// remove:
      //  [UIView setAnimationRepeatCount:1000]; 
      //  [UIView setAnimationRepeatAutoreverses:YES]; 

        CGFloat x = (CGFloat) (arc4random() % (int) self.view.bounds.size.width); 
        CGFloat y = (CGFloat) (arc4random() % (int) self.view.bounds.size.height); 

        CGPoint squarePostion = CGPointMake(x, y); 
        button.center = squarePostion; 
// add:
     [UIView setAnimationDelegate:self]; // as suggested by @Carl Veazey in a comment
        [UIView setAnimationDidStopSelector:@selector(animationLoop:finished:context:)];

        [UIView commitAnimations];
    }

并在方法中添加一个计数器（int）来检查它是否被执行超过1000次，如果想要阻止它......

and just add a counter (int) inside the method to check if it's executed more than 1000 times, if wanna stop it...

这篇关于在屏幕上随机移动对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！