iOS 悬浮可移动按钮

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
    btn.frame = CGRectMake(100, 100, 50, 50);
    btn.backgroundColor = [UIColor yellowColor];
    btn.clipsToBounds = YES;
    btn.layer.cornerRadius = 25;
    btn.tag = 10086;
    [self.view addSubview:btn];
    
    //添加手势
    //添加移动的手势
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(locationChange:)];
    pan.delaysTouchesBegan = YES;
    [btn addGestureRecognizer:pan];
    
}

- (void)locationChange:(UIPanGestureRecognizer *)recognizer
{
    
    CGPoint translation = [recognizer translationInView:self.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.view];
    
    if(recognizer.state==UIGestureRecognizerStateEnded|| recognizer.state==UIGestureRecognizerStateCancelled) {
        
        if(centerX>ScreenWidth/2) {
            
            thecenter=ScreenWidth-50;
            
        }else{
            
            thecenter=50;
            
        }
        [UIView animateWithDuration:0.3 animations:^{
            
            recognizer.view.center=CGPointMake(thecenter,
                                               
                                               recognizer.view.center.y+ translation.y);
            
        }];
        
    }
    

}