HarmonyOS 自定义弹窗（CustomDialog）如何实现安全区域避让

可以监听键盘高度来修改弹窗的offset实现效果，参考示例如下：

import { window } from '@kit.ArkUI';
import { common } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';

@CustomDialog
@Component
export struct CommentInputView {
  // 点击发送按钮的回调
  onSendAction?: (comment: string) => void;
  // 输入框绑定的控制器
  textAreaController: TextAreaController = new TextAreaController();
  // 光标位置
  @State caretIndex?: number = undefined;
  // 输入框内容
  @State private text?: string = undefined;
  // 若需要自定义弹窗中传入多个其他弹窗的的Controller，当前自定义弹窗的controller定义需放在其他传入的controller后面
  customDialogController: CustomDialogController;
  private context = getContext(this) as common.UIAbilityContext;
  @State dialogOffset: number = 20
  @State textOffset: number = 0

  /**
   * 在指定位置插入字符串
   * @param str 原字符串
   * @param index 插入位置
   * @param char 要插入的字符串
   * @returns 插入后的新字符串
   */
  private insertChar(str: string, index: number, char: string): string {
    return str.slice(0, index) + char + str.slice(index);
  }

  aboutToAppear(): void {
    let windowClass: window.Window | undefined = undefined;
    try {
      let promise = window.getLastWindow(this.context);
      promise.then((data) => {
        windowClass = data;
        try {
          windowClass.on('keyboardHeightChange', (data) => {
            if (data != 0) {
              this.textOffset = 0
              this.dialogOffset = 20
            } else {
              this.textOffset = -20
              this.dialogOffset = 0
            }
            console.info('Succeeded in enabling the listener for keyboard height changes. Data: ' +
            JSON.stringify(data));
          });
        } catch (exception) {
          console.error('Failed to enable the listener for keyboard height changes. Cause: ' +
          JSON.stringify(exception));
        }
        console.info('Succeeded in obtaining the top window. Data: ' + JSON.stringify(data));
      }).catch((err: BusinessError) => {
        console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(err));
      });
    } catch (exception) {
      console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(exception));
    }


  }

  build() {
    Stack() {
      Column({
        space: 8,
      }) {
        TextArea({
          text: this.text,
          placeholder: '欢迎大家积极评论，理性发言，友善讨论',
          controller: this.textAreaController,
        })
          .onChange((value) => {
            if (this.text !== value) {
              this.text = value;
            }
            if (this.caretIndex) {
              this.textAreaController.caretPosition(this.caretIndex);
              this.caretIndex = undefined;
            }
          })
          .fontSize(15)
          .fontColor(Color.Black)
          .placeholderColor(Color.Gray)
          .enterKeyType(EnterKeyType.Send)
          .backgroundColor(Color.White)
          .width('100%')
          .height(140)
          .borderRadius(0)
          .padding(0)
          .defaultFocus(true)
          .id('text_input')

        Row() {
          Row({
            space: 2,
          }) {
            this.EmojiBuilder('')
            this.EmojiBuilder('')
          }
          .backgroundColor(Color.Grey)
          .borderRadius(14)
          .height(28)

          Text('发布')
            .textAlign(TextAlign.Center)
            .fontColor(Color.Red)
            .fontSize(14)
            .backgroundColor(Color.Black)
            .borderRadius(14)
            .width(58)
            .height(28)
        }
        .alignItems(VerticalAlign.Center)
        .justifyContent(FlexAlign.SpaceBetween)
        .width('100%')
      }
      .offset({ x: 0, y: this.textOffset }) //2.2、弹窗位置
      .borderRadius({
        topLeft: 8,
        topRight: 8,
      })
      .padding({
        top: 16,
        left: 16,
        bottom: 8,
        right: 16,
      })
      .backgroundColor(Color.Red)
      .width('100%')
      .onClick(() => {
        // 拦截点击空白处
      })
    }
    .backgroundColor(Color.Green)
    .align(Alignment.Bottom)
    .onClick(() => {
      this.customDialogController.close();
    })
    .offset({ x: 0, y: this.dialogOffset }) //2.2、弹窗位置
  }

  @Builder
  private EmojiBuilder(emoji: string) {
    Text(emoji)
      .padding({
        left: 6,
        right: 6,
      })
      .height('100%')
      .onClick(() => {
        if (this.text) {
          this.caretIndex = this.textAreaController.getCaretOffset().index;
          this.text = this.insertChar(this.text, this.caretIndex, emoji);
          this.caretIndex += emoji.length;
        } else {
          this.text = emoji;
        }
      })
  }
}