HarmonyOS 如何使用全局弹窗更新Params？

@Component  
struct uicontext_customDialog {  
  @State message: string = "hello"  
  uiContext: UIContext = this.getUIContext();  
  promptAction: PromptAction = this.uiContext.getPromptAction();  
  contentNode = new ComponentContent(this.uiContext, wrapBuilder(buildText), new Params(this.message));  
  @State arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]  
  aboutToDisappear(): void {  
    // AlerDialog_Content()  
    AlertDialog.show(  
      {  
        title: 'title',  
        message: 'text',  
        autoCancel: true,  
        alignment: DialogAlignment.Bottom,  
        offset: { dx: 0, dy: -20 },  
        gridCount: 3,  
        confirm: {  
          value: 'button',  
          action: () => {  
            console.info('Button-clicking callback')  
          }  
        },  
        cancel: () => {  
          console.info('Closed callbacks')  
        }  
      })  
  }  
  build() {  
    Column() {  
      List() {  
        ForEach(this.arr, (item: number) => {  
          ListItem() {  
            Text('' + item)  
              .width('100%')  
              .height(100)  
              .fontSize(16)  
              .textAlign(TextAlign.Center)  
              .borderRadius(10)  
              .backgroundColor(0xFFFFFF)  
          }  
          .onClick(() => {  
            this.promptAction.openCustomDialog(this.contentNode, {})  
            this.contentNode.update(new Params("new message" + item));  
          })  
        }, (item: string) => item)  
      }  
    }  
  }  
}