Google Picker API + Angular2获取未捕获的TypeError:无法读取未定义的属性'handleAuthResult‘

import { Injectable } from '@angular/core';

declare var google: any;

@Injectable()
export class GooglePickerService {
  private pickerApiLoaded: boolean = false;

  constructor() {
    // 加载Google Picker API
    google.load('picker', '1', {
      callback: this.onPickerApiLoad.bind(this)
    });
  }

  onPickerApiLoad() {
    this.pickerApiLoaded = true;
  }

  handleAuthResult(authResult: any) {
    if (authResult && !authResult.error) {
      // 授权成功，执行相应操作
      this.showPicker();
    } else {
      // 授权失败，处理错误
      console.error('授权失败:', authResult.error);
    }
  }

  showPicker() {
    if (this.pickerApiLoaded) {
      const picker = new google.picker.PickerBuilder()
        .addView(google.picker.ViewId.DOCS)
        .setOAuthToken('YOUR_OAUTH_TOKEN')
        .setDeveloperKey('YOUR_DEVELOPER_KEY')
        .setCallback(this.onPickerCallback.bind(this))
        .build();
      picker.setVisible(true);
    } else {
      console.error('Google Picker API未加载');
    }
  }

  onPickerCallback(data: any) {
    if (data.action === google.picker.Action.PICKED) {
      const fileId = data.docs[0].id;
      // 处理选定的文件ID
      console.log('选定的文件ID:', fileId);
    }
  }
}