参考:https://www.infallibletechie.com/2020/03/how-to-call-method-in-lwc-in-specific.html
@track progress = 5000;
_interval;
connectedCallback() {
this._interval = setInterval(() => {
//this.progress = this.progress + 5000;
//alert( this.i++ );
this.getMsg(); //データ取得処理
refreshApex(this.msgShow);
if ( this.progress === 100000 ) {
clearInterval(this._interval);
}
}, this.progress);
}