HarmonyOS TextArea填充值，如何自动滚动到文本底部和如何手动失去焦点

@Entry 
@Component 
struct TextAreaExample { 
  @State text: string = '' 
  @State positionInfo: CaretOffset = { index: 0, x: 0, y: 0 } 
  @State maxLength: number= 0 
  controller: TextAreaController = new TextAreaController() 
 
  build() { 
    Column() { 
      TextArea({ 
        text: this.text, 
        placeholder: '请输入内容....', 
        controller: this.controller 
      }) 
        .placeholderFont({ size: 16, weight: 400 }) 
        .width(336) 
        .height(56) 
        .margin(20) 
        .fontSize(16) 
        .fontColor('#182431') 
        .backgroundColor('#FFFFFF') 
        .onChange((value: string) => { 
          this.text = value 
          let Length: number= value.length; 
          if(this.maxLength< Length){ 
            this.maxLength = Length 
            console.log('length='+this.maxLength)} 
        }) 
 
 
      Text(this.text) 
      Button('跳转到最后一行').onClick((event: ClickEvent) => { 
        this.controller.caretPosition(this.maxLength) 
      }) 
 
    }.width('100%').height('100%').backgroundColor('#F1F3F5') 
    //失去焦点事件 
    .onClick(()=> { 
      this.controller.stopEditing() 
    }) 
  } 
}