UISlider 监听所有的抬起后的事件

写了一个滑块，默认中间，滑动到左边，滑动到右边，都会触发事件。

WX20201124-161302@2x.png

- (UISlider *)slider {
    if (!_slider) {
        CGRect rect = CGRectMake((self.width - 120)/2, (self.height - 20)/2, 120, 20);
        _slider = [[UISlider alloc] initWithFrame:rect];
        [_slider setThumbImage:[UIImage imageNamed:@"滑块-1"] forState:UIControlStateNormal];
        [_slider setThumbImage:[UIImage imageNamed:@"滑块-1"] forState:UIControlStateHighlighted];
        _slider.minimumTrackTintColor = kWhiteColor;
        _slider.maximumTrackTintColor = kWhiteColor;
        _slider.value = 0.5;
        [_slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventTouchUpInside];
    }
    return _slider;
}

最终测试的时候，偶发监听不到UIControlEventTouchUpInside事件，网上一搜索全都是这个写法，内容都一样全是抄的，我能想到的是把各抬起事件都监听上，但写有点复杂，终于在各种一样的帖子下找到一条评论。

WX20201124-162047@2x.png

看了一下api尝试使用了continuous一下完美解决。

@property(nonatomic,getter=isContinuous) BOOL continuous;        // if set, value change events are generated any time the value changes due to dragging. default = YES

正确的代码如下：

- (UISlider *)slider {
    if (!_slider) {
        CGRect rect = CGRectMake((self.width - 120)/2, (self.height - 20)/2, 120, 20);
        _slider = [[UISlider alloc] initWithFrame:rect];
        [_slider setThumbImage:[UIImage imageNamed:@"滑块-1"] forState:UIControlStateNormal];
        [_slider setThumbImage:[UIImage imageNamed:@"滑块-1"] forState:UIControlStateHighlighted];
        _slider.minimumTrackTintColor = kWhiteColor;
        _slider.maximumTrackTintColor = kWhiteColor;
        _slider.value = 0.5;
        _slider.continuous = NO;
        [_slider addTarget:self action:@selector(sliderAction:) forControlEvents:UIControlEventValueChanged];
    }
    return _slider;
}

很少用到，有些细节用来记录一下。