HarmonyOS 如何在应用中动态的设置深浅色模式？

{  
  "color": [  
  {  
    "name": "start_window_background",  
  "value": "#FFFFFF"  
  },  
  {  
    "name": "background",  
  "value": "#FFFFFF"  
  },  
  {  
    "name": "font_color",  
  "value": "#FFFFFF"  
  },  
  {  
    "name": "button_background",  
  "value": "#0000FF"  
  }  
  ]  
}

// 对单个页面进行设置  
import ConfigurationConstant from '@ohos.app.ability.ConfigurationConstant';  
  
@Entry  
@Component  
struct ForceSetExample {  
  onPageShow() {  
    let applicationContext = getContext().getApplicationContext();  
    applicationContext.setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_DARK);  
  }  
  
  onPageHide() {  
    let applicationContext = getContext().getApplicationContext();  
    applicationContext.setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_LIGHT);  
    applicationContext.setColorMode(ConfigurationConstant.ColorMode.COLOR_MODE_NOT_SET);  
  }  
  
  build() {  
    Column() {  
      Text('进入页面强制设置为深色模式').fontSize(25).margin(15)  
      Text('退出页面时先设置为浅色模式').fontSize(25).margin(15)  
      Text('再设置为跟随系统').fontSize(25).margin(15)  
      Search({ placeholder: 'Type to search...' })  
        .searchButton('SEARCH')  
        .width(400)  
        .height(40)  
        .placeholderFont({ size: 14, weight: 400 })  
        .textFont({ size: 14, weight: 400 })  
        .margin(20)  
  
      Button('按钮一')  
        .width('50%').margin('10%').backgroundColor($r('app.color.background'))  
      Button('按钮二')  
        .width('50%').margin('10%')  
    }.width('100%')  
  }  
}