Show-dialog-box.md

Show a dialog box

These methods provide convenient ways to show a dialog box, and can be called from the UI thread or from a background thread:

• Simple dialog
• Action dialog

Simple dialog

Shows a simple dialog box displaying a message, an optional title, and a "Close" button for the user to dismiss it.

using System;
using System.Threading.Tasks;
using Windows.ApplicationModel.Core;
using Windows.UI.Core;
using Windows.UI.Popups;

public static async Task ShowDialogAsync(string contents, string title = null)
{
    var dialog = title == null ?
        new MessageDialog(contents) { CancelCommandIndex = 0 } :
        new MessageDialog(contents, title) { CancelCommandIndex = 0 };
    await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
        CoreDispatcherPriority.Normal, async () => await dialog.ShowAsync());
}

Action dialog

Shows a dialog box with a message, an optional title, and two buttons for "OK" and "Cancel".

This method takes a callback action that is invoked when the user presses OK. You can also provide your own strings for the title and the two buttons.

using System;
using System.Threading.Tasks;
using Windows.ApplicationModel.Core;
using Windows.UI.Core;
using Windows.UI.Popups;

public static async Task ShowActionDialogAsync(string contents, Action callback,
    string title = null, string okButtonText = "OK", string cancelButtonText = "Cancel")
{
    var dialog = title == null ?
        new MessageDialog(contents) { CancelCommandIndex = 1 } :
        new MessageDialog(contents, title) { CancelCommandIndex = 1 };
    dialog.Commands.Add(new UICommand(okButtonText, command => callback()));
    dialog.Commands.Add(new UICommand(cancelButtonText));
    await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(
        CoreDispatcherPriority.Normal, async () => await dialog.ShowAsync());
}

Usage

await ShowActionDialogAsync("Do you really want to delete all items?", 
    () => { /* delete all items */ }, "Warning");

See also

MessageDialog class
UICommand class
CoreDispatcher.RunAsync method
Lambda expressions (anonymous methods using the "=>" syntax)
?: operator