如何从 Xamarin.Forms 内本机启动外部应用程序？

Question

As the question title suggests, I'm looking for a way to launch an external app from within a Xamarin.Forms app. For example, my app has a list of addresses, and when the user taps on one of them, the built-in map app for the current platform would open (Google Maps for Android, Apple Maps for iOS). In case it matters, I am only targeting Android and iOS.

I could use a dependency service and write the app-launching code on a per-platform basis, of course, but I'd prefer if I only had to write it once. Is there a native way to do this in Xamarin.Forms? I was unable to find anything that officially documented this on the Xamarin site or forums.

Answer 1

Use Device.OpenUri and pass it the appropriate URI, combined with Device.OnPlatform to format the URI per platform

string url; 

Device.OnPlatform(iOS: () =>
  {
     url = String.Format("http://maps.apple.com/maps?q={0}", address);
  },
  Android: () =>
  {
    url = String.Format("http://maps.google.com/maps?q={0}", address);
  });

Device.OpenUri(url);

Answer 2

As of Xamarin.Forms v4.3.0.908675 (probably v4.3.0) Device.OpenUri is deprecated and you should use Launcher.TryOpenAsync from Xamarin.Essentials instead. Although you will find it troublesome, or at least I did.

Answer 3

Use Below code, and add namespaces Xamarin.Essentials and Xamarin.Forms

if (Device.RuntimePlatform == Device.iOS)
{
    // https://developer.apple.com/library/ios/featuredarticles/iPhoneURLScheme_Reference/MapLinks/MapLinks.html
    await Launcher.OpenAsync("http://maps.apple.com/?daddr=San+Francisco,+CA&saddr=cupertino");
}
else if (Device.RuntimePlatform == Device.Android)
{
    // opens the 'task chooser' so the user can pick Maps, Chrome or other mapping app
    await Launcher.OpenAsync("http://maps.google.com/?daddr=San+Francisco,+CA&saddr=Mountain+View");
}
else if (Device.RuntimePlatform == Device.UWP)
{
    await Launcher.OpenAsync("bingmaps:?rtp=adr.394 Pacific Ave San Francisco CA~adr.One Microsoft Way Redmond WA 98052");
}