Snackbar

Frameworks

.NET MAUI

Blazor

A snackbar is a toast with an action. It goes through the same service and the same queue, and every ToastConfig setting still applies. SnackbarConfig derives from ToastConfig and changes the defaults: DisplayMode = Snackbar (rectangular, 4px corners, full width on a phone, capped at 600 and centred on a wider screen), TextOverflow = MultiLine, QueueMode = Replace and PauseOnHover = true.

// MAUI - IToaster
var result = await toaster.SnackbarAsync("Message deleted", "Undo");
if (result == SnackbarResult.ActionInvoked)
    Restore();

// Body tap and action button are separate targets
await toaster.SnackbarAsync("New reply from Sam", "Mark read", cfg =>
{
    cfg.TapCommand = OpenReplyCommand;     // tapping the message
    cfg.ActionCommand = MarkReadCommand;   // tapping the button - never fires TapCommand
});

// Loading: a line along the top edge, open until you dispose the handle
using var loading = await toaster.LoadingSnackbarAsync("Uploading...", cfg =>
{
    cfg.ActionText = "Cancel";
    cfg.ActionCommand = new Command(cts.Cancel);
});
loading.Progress = 0.4;              // null (default) = indeterminate
loading.Text = "Uploading... 40%";   // updates in place

@inject IToastService ToastService

var result = await ToastService.SnackbarAsync("Message deleted", "Undo");

await ToastService.SnackbarAsync("New reply", "Mark read", cfg =>
{
    cfg.TapCallback = OpenReply;
    cfg.ActionCallback = MarkRead;
});

using var loading = await ToastService.LoadingSnackbarAsync("Uploading...");
loading.Progress = 0.4;

SnackbarAsync(text, actionText?, configure?, cancellationToken) returns Task<SnackbarResult>, which completes when the snackbar closes:

Result	When
ActionInvoked	The action button was pressed
TimedOut	The duration ran out
Dismissed	Body tap (DismissOnTap), or the token was cancelled (a queued snackbar is dropped without showing)
Replaced	A newer toast took its place (QueueMode.Replace, or a full stack)

LoadingSnackbarAsync(text, configure?) returns ILoadingSnackbar (Text, Progress, Closed, Dispose) once it is on screen. It has Duration = Zero and DismissOnTap = false, so it stays until you dispose it or the user presses its action.

SnackbarConfig	Type	Default	Description
ActionText	string?	null	Button label. Null = no button. Passing actionText makes the default duration 8s instead of 4s; configure can still change it
ActionCommand (MAUI) / ActionCallback (Blazor)	ICommand? / Action?	null	Runs when the button is pressed, before it closes
ActionTextColor	Color? / string?	inverse-primary token	Button label colour
IsLoading	bool	false	Top-edge progress line. Set for you by LoadingSnackbarAsync
Progress	double?	null	0-1 for the loading line. Null = indeterminate

New on ToastConfig, so plain toasts can use them too: ToastDisplayMode.Snackbar, ToastQueueMode.Replace (dismiss the queued toast that is showing and jump the queue), and PauseOnHover (holds the countdown and its progress bar while the pointer is over it or, on Blazor, focus is inside it; on MAUI desktop only, since a pointer recognizer on a phone takes real taps). Marquee, spinner, icon and colours work on a snackbar as they do on a toast. With ShowProgressBar, a snackbar’s countdown bar runs along the top edge rather than the bottom.

Accessibility: the screen-reader announcement includes the action (“Message deleted. Undo”). The button is a real Button / <button> at least 40 tall and 48 wide. A snackbar with an action defaults to 8 seconds, and you can set Duration = TimeSpan.Zero to keep an important action up until the user responds.

See Toast for everything a snackbar shares with a toast: position, colours, icon, spinner, marquee, queueing and safe-area handling.