MessageDialog ShowAsync throws accessdenied exception on second dialog

Okay I found a quick solution,

define a IAsyncOperation class varialble

IAsyncOperation<IUICommand> asyncCommand = null;

and set it to the ShowAsync method of MessageDialog

asyncCommand = msg.ShowAsync();

In the command handler for retry/try again check if asyncCommand is not null and cancel the last operation if necessary

if(asyncCommand != null)
{
   asyncCommand.Cancel();
}

Please let me if there is a better approach to this.

I am late to the party, but here's a way where you can always await the result of the dialog box, as well as not need to worry about calling too many in a row:

First define a static variable and method in your application:

 private static IAsyncOperation<IUICommand> messageDialogCommand = null;
 public async static Task<bool> ShowDialog(MessageDialog dlg) {

    // Close the previous one out
    if (messageDialogCommand != null) {
       messageDialogCommand.Cancel();
       messageDialogCommand = null;
    }

    messageDialogCommand = dlg.ShowAsync();
    await messageDialogCommand;
    return true;
 }

Now, you can pass in any dialog box and always await execution. This is why this returns a bool rather than void. You won't have to worry about collisions between multiples. Why not make this method accept a string? Because of title, and Yes/No command handlers that you may assign into the specific dialog box you are using.

Invoke such as:

await App.ShowDialog(new MessageDialog("FOO!"));

or

var dlg = new MessageDialog("FOO?", "BAR?");
dlg.Commands.Add(new UICommand("Yes", new UICommandInvokedHandler(YesHandler)));
dlg.Commands.Add(new UICommand("No", new UICommandInvokedHandler(NoHandler)));
await App.ShowDialog(dlg);

There is an answer for this on the MSDN forums that might help you here.

http://social.msdn.microsoft.com/Forums/en-US/winappswithhtml5/thread/c2f5ed68-aac7-42d3-bd59-dbf2673dd89b

I'm having a similar problem but my showAsync calls are in separate functions on separate threads so I can't drop a done() in there I don't think...

I was facing this same issue some days ago, and i solve it awaiting the ShowAsync and then making the recursive call that open the MessageDialog again.

public async void ShowDlg(){
    Action cmdAction = null;
    var msgDlg = new MessageDialog("Content.", "Title");
    msgDlg.Commands.Add(new UICommand("Retry", (x) => {
    cmdAction = () => ShowDlg();
    }));
    msgDlg.Commands.Add(new UICommand("Cancel", (x) => {
    cmdAction = () => <Action associated with the cancel button>;
    }));
    msgDlg.DefaultCommandIndex = 0;
    msgDlg.CancelCommandIndex = 1;

    await msgDlg.ShowAsync();
    cmdAction.Invoke();
}

Hope this help!