iOS AssistiveTouch效果-跟随手指移动的button

这是一个悬浮的按钮，类似于手机的AssistiveTouch效果，可以全工程悬浮的

http://code.cocoachina.com/view/135532

话不多说，上代码，复制黏贴即可

UIButton *btn=[[UIButton alloc]initWithFrame:CGRectMake(0,0,50,50)];

btn.backgroundColor=[UIColor orangeColor];

btn.layer.cornerRadius=25;

btn.center=self.window.rootViewController.view.center;

[self.window.rootViewController.view addSubview:btn];

UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc]

initWithTarget:self

action:@selector(handlePan:)];

[btn addGestureRecognizer:panGestureRecognizer];

- (void) handlePan:(UIPanGestureRecognizer*) recognizer

{

CGPoint translation = [recognizer translationInView:self.window.rootViewController.view];

CGFloat centerX=recognizer.view.center.x+ translation.x;

CGFloat thecenter=0;

recognizer.view.center=CGPointMake(centerX,

recognizer.view.center.y+ translation.y);

[recognizer setTranslation:CGPointZero inView:self.window.rootViewController.view];

if(recognizer.state==UIGestureRecognizerStateEnded|| recognizer.state==UIGestureRecognizerStateCancelled) {

if(centerX>ScreenWidth/2) {

thecenter=ScreenWidth-50/2;

}else{

thecenter=50/2;

}

[UIView animateWithDuration:0.3 animations:^{

recognizer.view.center=CGPointMake(thecenter,

recognizer.view.center.y+ translation.y);

}];

}

}