当 UISlider 向左移动时获得负值

Getting negative value when UISlider goes left(当 UISlider 向左移动时获得负值)

问题描述

我试图弄清楚如何在滑块返回时获得负值.

I was trying to figure out how to get a negative value of the slider when it goes back.

当我从左向右滑动时，它返回一个正值.我需要它在返回时返回一个负值(从右到左).

When I slide from left to right it returns a positive value. I need it to return a negative value when it goes back (from right to left).

换句话说，我如何检测到滑块正在返回?

In other words, how could I detect that the slider is going back?

    self.borderSlider = [[UISlider alloc] initWithFrame:CGRectMake(0, 0, 200, 30)];
    self.borderSlider.center = CGPointMake(self.view.centerX, SCREEN_WIDTH / 2);
    self.borderSlider.minimumValue = 0.0f;
    self.borderSlider.maximumValue = 100.0f;
    self.borderSlider.tintColor = [UIColor grayColor];
    [self.borderSlider addTarget:self action:@selector(borderSliderValueChanged:) forControlEvents:UIControlEventValueChanged];

推荐答案

我遇到了同样的问题，所以我开发了它，查看这个 repo:

I had the same problem so I've developed it, check this repo: Repo

slider?.amplitude = 50 
slider?.sliderDidChange = { [weak slider] value in
        if value > 10 {
            slider?.activeColor = .blue
        } else if value < 0 {
            slider?.activeColor = .red
        } else {
            slider?.activeColor = .lightGray
        }
    }

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