HarmonyOS 打开系统邮箱并且展示邮件地址

可以通过拼接uri传递收件人，抄送人，内容等参数，关键代码参考如下：

mail({ subject= '', recipients=[], body='', ccRecipients=[], bccRecipients=[] }: mainOptions, callback: Function) {
  let mailUri: string = '';
  mailUri += recipients?.join(',') || '';
  mailUri += '?cc=' + ccRecipients?.join(',') || '';
  mailUri += '&bcc=' + bccRecipients?.join(',') || '';
  mailUri += '&subject=' + subject;
  mailUri += '&body=' + body;
  Logger.info('mailUri ', mailUri, 'ccRecipients:' + ccRecipients, 'bccRecipients:' + bccRecipients);
  this.startEmailApp(mailUri, callback);
}

startEmailApp = (mailUri, callback) => {
  let want: Want = {
    bundleName: 'com.huawei.hmos.email',
    abilityName: 'EntryAbility',
    moduleName: 'entry',
    uri: 'mailto:' + mailUri,
    action: 'ohos.want.action.viewData',
  };
  Logger.info('want ', JSON.stringify(want));
  try {
    this.ctx.uiAbilityContext.startAbility(want)
      .then(() => {
        Logger.info('startAbility success');
      })
      .catch((err: BusinessError) => {
        Logger.info('startAbility error.', err.message);
        callback(err.message);
      })
  } catch (e) {
    callback(e);
    Logger.info('error:', e);
  }
}