my.getScreenBrightness

my.getScreenBrightness({
  success(res) {
    console.log('Current brightness:', res.brightness);
  }
});

Page({
  data: {
    brightnessPercent: 0
  },

  onLoad() {
    my.getScreenBrightness({
      success: (res) => {
        this.setData({
          brightnessPercent: Math.round(res.brightness * 100)
        });
      }
    });
  }
});

Page({
  data: {
    brightness: 0.5
  },

  onLoad() {
    my.getScreenBrightness({
      success: (res) => {
        this.setData({ brightness: res.brightness });
      }
    });
  },

  onBrightnessChange(e) {
    const value = e.detail.value / 100;
    my.setScreenBrightness({
      brightness: value,
      success: () => {
        this.setData({ brightness: value });
      }
    });
  }
});