how to print 2 alerts consecutives WinJS

问题

I want to print two alerts on my app, one to show an application and after pressing close button on first alert to show the second alert

Windows.UI.Popups.MessageDialog("Hello Welcome").showAsync();
Windows.UI.Popups.MessageDialog("Welcome to my app").showAsync();

if I just print an alert, everything works good but on the other scenary (two alerts) the code stops with an error, how to fix that??

回答1:

You can't have multiple MessageDialogs open at the same time. Since the showAsync returns immediately (async reference), your code needs to wait until it's closed.

To do that you'd need to rely on the Promise returned by showAsync:

Windows.UI.Popups.MessageDialog("Hello Welcome")
    .showAsync().done(function() {
         Windows.UI.Popups.MessageDialog("Welcome to my app").showAsync()
    });

Above, the code waits for the done callback to be called on the Promise and then shows a second dialog.

来源：https://stackoverflow.com/questions/20532134/how-to-print-2-alerts-consecutives-winjs