HarmonyOS router.back()如何获取返回值

可以在A、B、C页面传参时额外设置一个变量来标识是从哪个页面跳转到的选人控件，参考代码如下：

1、页面A：

import { router } from '@kit.ArkUI';

@Entry
@Component
struct Index {
  @State message: string = 'Hello World';

  build() {
    Column() {

      Button('点击')
        .onClick(() => {
          router.pushUrl({
            url: 'pages/index3',
            params: {
              flag: '1',
              data: 'Hello World'
            }
          })
        })
    }
    .justifyContent(FlexAlign.Center)
    .height('100%')
    .width('100%')
  }
}

2、选人控件：

import { router } from '@kit.ArkUI';

@Entry
@Component
struct Index3 {
  @State message: string = 'Hello World';

  aboutToAppear(): void {
    let param = router.getParams() as Record<string, string>
    console.log(`参数一：${param['flag']}`);
    console.log(`参数二：${param['data']}`);
    if (param['flag'] == '1') {
      console.log(`页面A`)
    }
  }

  build() {
    Column() {
      Text('page3')

      Button('点击')
        .onClick(() => {
          router.back({
            url: 'pages/Index'
          })
        })
    }
    .justifyContent(FlexAlign.Center)
    .height('100%')
    .width('100%')
  }
}