滑动时 事件 value一直在变化
[self.adjustSlider addTarget:self action:@selector(progressChanged:)forControlEvents:UIControlEventValueChanged];
监听value变化 可以被一替代
[self.adjustSlider addObserver:self forKeyPath:@"value" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];
加上后事件 只有停止时 触发 forControlEvents:UIControlEventValueChanged
self.adjustSlider.continuous = NO;
TouchUp 手松开事件 UpInside 和UpOutside 和在一起
[self.adjustSlider addTarget:self action:@selector(progressChanged1:)forControlEvents:UIControlEventTouchUpInside|UIControlEventTouchUpOutside];