#pragma mark - 隨機數
 
- (NSInteger)getRandomNumber:(CGFloat)from to:(CGFloat)to
{
 return (NSInteger)(from + (arc4random() % ((NSInteger)to - (NSInteger)from + 1)));
}
 
 
#pragma mark - 隨機按鈕
 
- (void)createRandomBtnWithType:(FruitType)fruitType andText:(NSString *)textString
{
 CGFloat minY = kBtnMinY + kBtnDiameter * 0.5 + kMargin;
 CGFloat maxY = self.bounds.size.height - kBtnDiameter * 0.5 - kMargin;
 CGFloat minX = kBtnMinX + kMargin;
 CGFloat maxX = DEF_SCREEN_WIDTH - kBtnDiameter * 0.5 - 0 - kMargin;
 
 CGFloat x = [self getRandomNumber:minX to:maxX];
 CGFloat y = [self getRandomNumber:minY to:maxY];
 
 BOOL success = YES;
 for (int i = 0; i < self.centerPointArr.count; i ++) {
  NSValue *pointValue = self.centerPointArr[i];
  CGPoint point = [pointValue CGPointValue];
  //如果是圓 /^2 如果不是圓 不用/^2
  if (sqrt(pow(point.x - x, 2) + pow(point.y - y, 2)) <= kBtnDiameter + kMargin) {
   success = NO;
   [self createRandomBtnWithType:fruitType andText:textString];
   return;
  }
 }
 if (success == YES) {
  NSValue *pointValue = [NSValue valueWithCGPoint:CGPointMake(x, y)];
  [self.centerPointArr addObject:pointValue];
  
  UIButton *randomBtn = [UIButton buttonWithType:0];
  randomBtn.bounds = CGRectMake(0, 0, kBtnDiameter, kBtnDiameter);
  randomBtn.center = CGPointMake(x, y);
  [randomBtn setTitleColor:[UIColor whiteColor] forState:0];
  [self addSubview:randomBtn];
  [randomBtn addTarget:self action:@selector(randomBtnClick:) forControlEvents:UIControlEventTouchUpInside];
  
  [self.randomBtnArr addObject:randomBtn];
  [self.randomBtnArrX addObject:randomBtn];
  
  //區(qū)分
  if (fruitType == FruitTypeTimeLimited) {
   randomBtn.tag = kUnlimitedBtnTag + self.centerPointArr.count - 1;
   [self.timeLimitedBtnArr addObject:randomBtn];
   randomBtn.backgroundColor = [UIColor blueColor];
  } else if (fruitType == FruitTypeUnlimited) {
   randomBtn.tag = kTimeLimitedBtnTag + self.centerPointArr.count - 1;
   [self.unlimitedBtnArr addObject:randomBtn];
   randomBtn.backgroundColor = [UIColor redColor];
  }
  [randomBtn setTitle:textString forState:0];
  
  [self animationScaleOnceWithView:randomBtn];
  [self animationUpDownWithView:randomBtn];
 }
}

#pragma mark - 動畫
 
- (void)animationScaleOnceWithView:(UIView *)view
{
 [UIView animateWithDuration:0.2 animations:^{
  view.transform = CGAffineTransformMakeScale(1.05, 1.05);
 } completion:^(BOOL finished) {
  [UIView animateWithDuration:0.2 animations:^{
   view.transform = CGAffineTransformMakeScale(1.0, 1.0);
  } completion:^(BOOL finished) {
  }];
 }];
}
 
- (void)animationUpDownWithView:(UIView *)view
{
 CALayer *viewLayer = view.layer;
 CGPoint position = viewLayer.position;
 CGPoint fromPoint = CGPointMake(position.x, position.y);
 CGPoint toPoint = CGPointZero;
 
 uint32_t typeInt = arc4random() % 100;
 CGFloat distanceFloat = 0.0;
 while (distanceFloat == 0) {
  distanceFloat = (6 + (int)(arc4random() % (9 - 7 + 1))) * 100.0 / 101.0;
 }
 if (typeInt % 2 == 0) {
  toPoint = CGPointMake(position.x, position.y - distanceFloat);
 } else {
  toPoint = CGPointMake(position.x, position.y + distanceFloat);
 }
 
 CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
 animation.removedOnCompletion = NO;
 animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
 animation.fromValue = [NSValue valueWithCGPoint:fromPoint];
 animation.toValue = [NSValue valueWithCGPoint:toPoint];
 animation.autoreverses = YES;
 CGFloat durationFloat = 0.0;
 while (durationFloat == 0.0) {
  durationFloat = 0.9 + (int)(arc4random() % (100 - 70 + 1)) / 31.0;
 }
 [animation setDuration:durationFloat];
 [animation setRepeatCount:MAXFLOAT];
 
 [viewLayer addAnimation:animation forKey:nil];
}