问如何在Promise.all中将子接收器api调用转换为Angular9？

EN

Promise.all(this.hostName.slice(0, this.Id.length).map((hostName) => {
    return this.serviceC.status(hostName)
    .then(res => {
        // Here `this.serviceB.retry(oretry).subscribe` must be promisified, 
        // in order to keep the promise chain, thence `Promise.all()` informed.
        return new Promise((resolve, reject) => { 
            const oretry: ORInterface = {
                'oQId': res.rows[0].qid,
                'reason': this.reason
            };
            this.serviceB.retry(oretry).subscribe(resolve); // No need to test if (i === this.serverId.length - 1). 
                                                            // The last .subscribe(resolve) to fire will trigger this.dialog.close() below
        });
    });
}))
.then(() => {
    this.dialog.close();
})
.catch(err => {
    console.log(err);
    this.dialog.close(); // presumably
});