HarmonyOS Flex布局如何设置最大行数

请看下如下demo:

import measure from '@ohos.measure'
import display from '@ohos.display';

const childMaxWidth:number = 325 //为了方便后续计算，这里的宽度数值为px
let displayClass: display.Display | null = null;
let componentWidth:number = 0;
try {
  displayClass = display.getDefaultDisplaySync();
  componentWidth = displayClass.width
} catch (exception) {
  console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
}

@Component
struct TextItem{
  @State message:string = ""
  @Prop fontSizeData:number
  build() {
    Text(this.message)
      .fontSize(this.fontSizeData)
      .margin({left:10,top:10})
      .backgroundColor('#c4c2cc')
      .constraintSize({maxWidth:childMaxWidth + 'px'})
      .maxLines(1)
      .textOverflow({overflow:TextOverflow.Ellipsis})
  }
}

@Entry
@Component
struct Index2 {
  @State @Watch('IndexChange')index:number = 0
  @State @Watch('textChange') message: string = ''
  @State FlexWidth: string = '80%';
  @State newIndex:number = 0;
  @State heightControl: number|string = 100;
  @State ButtonText:string = '∨';
  @State AllData:string[] = ['1','22','333','44444','55','666','7777','8888888888888','99','7777','8888888888888','99','7777','8888888888888','99','7777','8888888888888','99']
  @State SomeData:string[] = []
  @State ShowData:string[] = []
  @State fontSizeData:number = 30
  @State AllWidth:number = 0
  @State textWidth:number = 0
  @State restrictWidth: number = 0;

  IndexChange(){
    if(this.AllWidth >= (this.restrictWidth - childMaxWidth) && this.AllWidth <= (this.restrictWidth)){
      this.newIndex = this.index
      console.log('text1 newIndex',this.newIndex)
      console.log('text1 change',this.newIndex)
    }
  }

  textChange(){
    let content:string = this.message
    this.textWidth = measure.measureText({
      textContent: content,
      fontSize: this.fontSizeData
    })
    if(this.textWidth > childMaxWidth){
      this.AllWidth += childMaxWidth
    }else{
      this.AllWidth += this.textWidth
    }

    console.log('text1 content',content)
    console.log('text1 Width',this.textWidth)
  }

  aboutToAppear(): void {
    if(componentWidth != 0){
      this.restrictWidth = Math.floor((parseFloat(this.FlexWidth) * componentWidth) * 1.3 * 0.01)
      console.log('text1 componentWidth',componentWidth)
      console.log('text1 restrictWidth',this.restrictWidth)
    }
    for(let i = 0;i < this.AllData.length;i++){
      this.message = this.AllData[i]
      this.index = i
    }
    console.log('text1 change newIndex',this.newIndex)
    this.SomeData = this.AllData.slice(0,this.newIndex+1)
    this.ShowData = this.SomeData
  }

  build() {
    Row() {
      Column() {
        Flex({wrap:FlexWrap.Wrap}){
          ForEach(
            this.ShowData,
            (item:string)=>{
              TextItem({message:item,fontSizeData:this.fontSizeData})
            }
          )
          Button(this.ButtonText)
            .onClick(()=>{
              if(this.heightControl === 100){
                this.heightControl = '100%'
                this.ButtonText = '^'
                this.ShowData = this.AllData
              }else{
                this.heightControl = 100
                this.ButtonText = 'v'
                this.ShowData = this.SomeData
              }
            })
            .width(40)
            .height(30)
            .margin({left:10,top:10})
        }
        .constraintSize({ maxHeight: this.heightControl })
        .border({width:1})
        .width(this.FlexWidth)
        .margin({left:'5%'})
        .clip(true)

      }
      .width('100%')
    }
    .height('100%')
  }
}