Button("登陆")
        .width("100%")
        .backgroundColor(Color.Orange)
        .fontColor(Color.Black)
        .margin({
          bottom: 10
        })
        .onClick(() => {
          if (this.message == "123") {
            router.pushUrl({
              url: "pages/MainPage"
            })
          }
          else {
            promptAction.showToast({
              message: "密码错误，请重新输入"
            })
          }
        })

ForEach(
  arr: Array,
  itemGenerator: (item: any, index?: number) => void,
  keyGenerator?: (item: any, index?: number): string => string
)

@Entry
@Component
struct Parent {
  @State simpleList: Array<string> = ['one', 'two', 'three'];

  build() {
    Row() {
      Column() {
        ForEach(this.simpleList, (item: string) => {
          ChildItem({ item: item })
        }, (item: string) => item)
      }
      .width('100%')
      .height('100%')
    }
    .height('100%')
    .backgroundColor(0xF1F3F5)
  }
}

@Component
struct ChildItem {
  @Prop item: string;

  build() {
    Text(this.item)
      .fontSize(50)
  }
}

LazyForEach(
    dataSource: IDataSource,             // 需要进行数据迭代的数据源
    itemGenerator: (item: any, index?: number) => void,  // 子组件生成函数
    keyGenerator?: (item: any, index?: number) => string // 键值生成函数
): void

import promptAction from '@ohos.promptAction';

@Entry
@Component
struct ForEachPage {
  @State message: string = 'Hello World'
  @State simpleList: Array<string> = ['one', 'two', 'three'];
  @State ImgList: Array<string> = ['https://img95.699pic.com/photo/40250/3647.jpg_wh300.jpg', 'https://img.iplaysoft.com/wp-content/uploads/2019/free-images/free_stock_photo.jpg', 'https://pica.zhimg.com/v2-3b4fc7e3a1195a081d0259246c38debc_720w.jpg?source=172ae18b'];

  build() {
    Row() {
      Column() {
        Text(this.message)

        Swiper() {
          ForEach(this.simpleList, (item: string) => {
            Text(item)
              .fontSize(50)
              .fontWeight(FontWeight.Bold)
              .width("100%")
              .height(200)
              .backgroundColor(Color.Orange)
              .onClick(() => {


                promptAction.showToast({
                  message: item
                })


              })


          },)

        }.autoPlay(true)


        Swiper() {

          ForEach(this.ImgList, (item: string) => {

            Image(item).onClick(() => {

            })


          })
        }.autoPlay(true).indicator(true)
      }
      .width('100%')
    }
    .height('100%')
  }
}

// Basic implementation of IDataSource to handle data listener
class BasicDataSource implements IDataSource {
  private listeners: DataChangeListener[] = [];
  private originDataArray: string[] = [];

  public totalCount(): number {
    return 0;
  }

  public getData(index: number): string {
    return this.originDataArray[index];
  }

  // 该方法为框架侧调用，为LazyForEach组件向其数据源处添加listener监听
  registerDataChangeListener(listener: DataChangeListener): void {
    if (this.listeners.indexOf(listener) < 0) {
      console.info('add listener');
      this.listeners.push(listener);
    }
  }

  // 该方法为框架侧调用，为对应的LazyForEach组件在数据源处去除listener监听
  unregisterDataChangeListener(listener: DataChangeListener): void {
    const pos = this.listeners.indexOf(listener);
    if (pos >= 0) {
      console.info('remove listener');
      this.listeners.splice(pos, 1);
    }
  }

  // 通知LazyForEach组件需要重载所有子组件
  notifyDataReload(): void {
    this.listeners.forEach(listener => {
      listener.onDataReloaded();
    })
  }

  // 通知LazyForEach组件需要在index对应索引处添加子组件
  notifyDataAdd(index: number): void {
    this.listeners.forEach(listener => {
      listener.onDataAdd(index);
    })
  }

  // 通知LazyForEach组件在index对应索引处数据有变化，需要重建该子组件
  notifyDataChange(index: number): void {
    this.listeners.forEach(listener => {
      listener.onDataChange(index);
    })
  }

  // 通知LazyForEach组件需要在index对应索引处删除该子组件
  notifyDataDelete(index: number): void {
    this.listeners.forEach(listener => {
      listener.onDataDelete(index);
    })
  }

  // 通知LazyForEach组件将from索引和to索引处的子组件进行交换
  notifyDataMove(from: number, to: number): void {
    this.listeners.forEach(listener => {
      listener.onDataMove(from, to);
    })
  }
}

class MyDataSource extends BasicDataSource {
  private dataArray: string[] = [];

  public totalCount(): number {
    return this.dataArray.length;
  }

  public getData(index: number): string {
    return this.dataArray[index];
  }

  public addData(index: number, data: string): void {
    this.dataArray.splice(index, 0, data);
    this.notifyDataAdd(index);
  }

  public pushData(data: string): void {
    this.dataArray.push(data);
    this.notifyDataAdd(this.dataArray.length - 1);
  }
}

@Entry
@Component
struct MyComponent {
  private data: MyDataSource = new MyDataSource();
   
  aboutToAppear() {
    for (let i = 0; i <= 20; i++) {
      this.data.pushData(`Hello ${i}`)
    }
  }

  build() {
    List({ space: 3 }) {
      LazyForEach(this.data, (item: string) => {
        ListItem() {
          Row() {
            Text(item).fontSize(50)
              .onAppear(() => {
                console.info("appear:" + item)
              })
          }.margin({ left: 10, right: 10 })
        }
      }, (item: string) => item)
    }.cachedCount(5)
  }
}