Xamarin.iOS Alerts Display Modal Alert Dialog
Example
It was common practice to use NSRunLoop to show modal UIAlertView to block code execution until user input is processed in iOS; until Apple released the iOS7, it broke few existing apps. Fortunately, there is a better way of implementing it with C#’s async/await.
Here’s the new code taking advantage of async/await pattern to show modal UIAlertView:
Task ShowModalAletViewAsync (string title, string message, params string[] buttons)
{
var alertView = new UIAlertView (title, message, null, null, buttons);
alertView.Show ();
var tsc = new TaskCompletionSource ();
alertView.Clicked += (sender, buttonArgs) => {
Console.WriteLine ("User clicked on {0}", buttonArgs.ButtonIndex);
tsc.TrySetResult(buttonArgs.ButtonIndex);
};
return tsc.Task;
}
//Usage
async Task PromptUser() {
var result = await ShowModalAletViewAsync
("Alert", "Do you want to continue?", "Yes", "No"); //process the result
}
