【每日学点HarmonyOS Next知识】 状态变量、公共Page、可见区域变化回调、接收参数、拖拽排序控件

发布于：2025-03-10 ⋅ 阅读:(22) ⋅ 点赞:(0)
1、HarmonyOS 在定时器里面改变@state修饰的变量，无法更新UI吗？

将函数function写成了封装函数的形式就可以了

@Entry
@Component
struct Index {
  @State acSetValve: number = 0;

  aboutToAppear(): void {
    setInterval(() => {
      this.acSetValve += 200;
      console.log('hahhah' + this.acSetValve)
    } ,100)
  }

  build() {
    Row() {
      Column() {
        Text(this.acSetValve.toString())
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
    }
    .height('100%')
  }
}
2、HarmonyOS 写一个公共的page，然后其他具体的page继承它，在公共page的做一些处理？

demo参考：

//主页面  FirstTest.ets
import { FirstTest2 } from "./FirstTest2"

@Entry
@Component
struct FirstTest {
  @State message1: string = 'Hello World';
  // 显隐控制设置为不占用

  build() {
    Column() {
      Text("FirstTest：" + this.message1)
        .fontSize(25)
        .fontWeight(FontWeight.Bold)
      //FirstTest2页面数据传递参考API：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/ArkTS-link-0000001820999565#ZH-CN_TOPIC_0000001857916041__%E6%A6%82%E8%BF%B0
      //FirstTest2为Component修饰的组件，并且进行export，然后在FirstTest进行导入直接使用即可，可以多个页面复用
      FirstTest2({message2:this.message1});
    }
  }
}

//复用组件  FirstTest2.ets
@Component
export struct FirstTest2 {
  @State test:string = "FirstTest2"
  @Link message2: string ;

  build() {
    Row() {
      Column() {
        Text("FirstTest2:" + this.test)
          .fontSize(25)
          .fontWeight(FontWeight.Bold)

        Text("FirstTest2:" + this.message2)
          .fontSize(25)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
    }
    .height('100%')
  }
}
3、HarmonyOS onVisibleAreaChange事件没有触发？

添加onVisibleAreaChange事件监听，只有第一屏可以触发，切到第二屏没有触发。影响埋点上报

onVisibleAreaChange规格上不支持监控由改变offset引起的组件区域变化。若要实现切屏监控，请使用swiper组件。

文档参考：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/ts-container-swiper-V5

4、HarmonyOS router.pushNamedRoute参数传递 在接收页面怎么接收？

可以通过router.getParams();接收参数，API链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-router-V5#ZH-CN_TOPIC_0000001884917590__routergetparams

参考demo如下:

import router from '@ohos.router';
class innerParams {
  array:number[]
  constructor(tuple:number[]) {
    this.array = tuple
  }
}

class routerParams {
  text:string
  data:innerParams
  constructor(str:string, tuple:number[]) {
    this.text = str
    this.data = new innerParams(tuple)
  }
}

@Entry
@Component
struct Router1 {

  build() {

    Column(){
      Column(){
        Text("我是页面1").fontSize(50)
      }
      Column(){

        Button("跳转")
          .onClick(()=>{
            router.pushUrl({
              url: 'pages/Router11',
              params: new routerParams('message' ,[123,456,789])
            })
          })
      }
    }
    .width('100%')
    .height('100%')
  }
}
import router from '@ohos.router';

class innerParams {
  array:number[]

  constructor(tuple:number[]) {
    this.array = tuple
  }
}

class routerParams {
  text:string
  data:innerParams
  constructor(str:string, tuple:number[]) {
    this.text = str
    this.data = new innerParams(tuple)
  }
}

@Entry
@Component
struct Router11 {

  aboutToAppear(): void {
    let s:number[]=((router.getParams() as routerParams).data as innerParams).array
    console.log("*********:"+s);
  }
  build() {
    Column(){
      Text("123").fontSize(50)
      Row(){
        Text("33333").fontSize(50)
      }
    }
    .width('100%')
    .height('100%')
    .opacity(0.5)
    .backgroundColor(Color.Pink)

  }
}
5、HarmonyOS 拖拽排序以及控件平移效果是否有工具类可以用，当前控件数据数量上限无法满足？

拖拽排序以及控件平移效果是否有工具类可以用，当前控件数据数量上限无法满足

动画效果可以参考以下demo：

@Entry
@Component
struct AnimationPage {
  @Provide desX: number = 0;
  @Provide desY: number = 0;

  @Builder
  TabBar(index: number) {
    Column() {
      Image($r("app.media.icon"))
        .width(38)
        .height(38)
      Text(index == 1 ? "分类" : index.toString())
    }
    .onAreaChange((oldValue: Area, newValue: Area) => {
      if (index == 1) {
        console.log("onAreaChange========= newValue:" + JSON.stringify(newValue))
        this.desX = newValue.globalPosition.x as number
        this.desY = newValue.globalPosition.y as number
      }
    })
  }

  build() {
    Column() {
      Category()
      Column() {
        Image($r("app.media.icon"))
          .width(38)
          .height(38)
      }
      .onAreaChange((oldValue: Area, newValue: Area) => {
        console.log("onAreaChange========= newValue:" + JSON.stringify(newValue))
        this.desX = newValue.globalPosition.x as number
        this.desY = newValue.globalPosition.y as number
      })
    }
    .width("100%")
    .height("100%")
  }
}

@Component
struct Category {

  @State dataList:number[] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]

  build() {
    Column() {
      Flex({direction:FlexDirection.Row, justifyContent: FlexAlign.SpaceBetween, wrap: FlexWrap.Wrap}) {
        ForEach(this.dataList, (item:number) => {
          ListItemComponent()
        })
      }
      .width('100%')
      .height('80%')
      .backgroundColor(Color.White)
    }
  }
}

@Observed
class AnimationBean {
  animationAppear: Boolean = false;
  id:number = -1;
}

@Component
struct ListItemComponent {
  @State animationList: AnimationBean[] = []
  static index: number = 0;
  @Consume desX: number;
  @Consume desY: number;

  @Provide orgX: number = 0;
  @Provide orgY: number = 0;


  @Builder
  BuildAnimationItem() {
    Image($r("app.media.app_icon"))
      .width(41)
      .height(41)
      .id("test")
      .onClick(() => {
        this.startAnimation();
      })
      .onAreaChange((oldValue:Area, newValue:Area) => {
        this.orgX = newValue.globalPosition.x as number
        this.orgY = newValue.globalPosition.y as number
        console.log("onAreaChage==========" + JSON.stringify(newValue))
      })
  }

  startAnimation() {
    const animation = new AnimationBean();
    animation.id = ListItemComponent.index++
    this.animationList.push(animation)
    animateTo({
      duration: 800,
      curve: Curve.FastOutLinearIn,
      onFinish: () => {
        animation.animationAppear = false;
        this.animationList = this.animationList.filter((item: AnimationBean) => {
          return item.animationAppear
        })
      }
    }, () => {
      animation.animationAppear = true;
    })
  }

  @Builder
  BuildItem() {
    Row() {
      Stack() {
        this.BuildAnimationItem()

        ForEach(this.animationList, (item: AnimationBean) => {
          AnimationChild({ item: item , AnimationView:this.BuildAnimationItem})
        }, (item: AnimationBean, index: number) => {
          return item.id.toLocaleString()
        })
      }
    }
    .width("20%")
    .height(60)
  }

  build() {
    this.BuildItem()
  }
}


@Component
struct AnimationChild {
  @ObjectLink item: AnimationBean;
  @Consume desX: number;
  @Consume desY: number;
  @Consume orgX: number;
  @Consume orgY: number;

  @BuilderParam
  AnimationView:() => void;

  build() {
    Row() {
      this.AnimationView()
    }
    .zIndex(5)
    .translate(this.item.animationAppear ? { x: (this.desX - this.orgX -20), y: (this.desY - this.orgY) } : { x: 0 })
  }
}

网站公告

今日签到

点亮在社区的每一天
去签到

热门文章

最新发布