switch case 语句中的异步等待不起作用

Question

我们可以使用关键字 await 在 switch case 语句中等待承诺的解决吗？在我的角度组件中，我有以下代码使我的应用程序崩溃。

switch (this.status) {
                case 'opened':
                  break;
                case 'payed':
                  this.getIntervalStatusSubscription.unsubscribe();
                  this.localStorageService.storePaymentIsMade(true);
                  await this.dbService.addOrderPaymentResult(ProcessResult.done, this.printerVMService.getSessionId()).toPromise();
                  this.router.navigate(['welcome/paying/paying_accepted']);
                  break;
                case 'closed':
                  this.getIntervalStatusSubscription.unsubscribe();
                  this.paymentSessionIsClosed = true;
                 await this.dbService.addOrderPaymentResult(ProcessResult.error, this.printerVMService.getSessionId()).toPromise();
                  this.router.navigate(['welcome']);
                  break;
                case 'used':
                  this.getIntervalStatusSubscription.unsubscribe();
                  this.router.navigate(['welcome']);
                  break;
                default:
                  console.error('status don\'t exist');
                  this.utils.displayAlertError(this.device.getIntervalStatus);
                  this.router.navigate(['welcome']);
              }

经过几次测试，在我看来，错误似乎来自以await. 你能告诉我有什么问题吗？我想this.dbService.addOrderPaymentResult(ProcessResult.done, this.printerVMService.getSessionId())在去之前同步执行哪个返回 observable this.router.navigate(['welcome/paying/paying_accepted']);这就是为什么我选择使用toPromise()和await

Answer 1

是的你可以：

async function trySwitch(status) {
    switch(status) {
        case 'opened':
            console.log('1');
            break;
        case 'closed':
            console.log('2');
            await new Promise(r => setTimeout(r, 1000));
            console.log('3');
            break;
    }
}

trySwitch('opened');
trySwitch('closed');