Android Training精要(四) Intent注意事项

PackageManager packageManager = getPackageManager();
List<ResolveInfo> activities = packageManager.queryIntentActivities(mapIntent, 0);
boolean isIntentSafe = activities.size() > 0;

// Start an activity if it's safe
if (isIntentSafe) {
startActivity(mapIntent);
}

Intent intent = new Intent(Intent.ACTION_SEND);
// Always use string resources for UI text.
// This says something like "Share this photo with"
String title = getResources().getString(R.string.chooser_title);
// Create and start the chooser
Intent chooser = Intent.createChooser(intent, title);
startActivity(chooser);