Bug 23786 - DisplayAlert causes NSInvalidArgumentException in iOS 7.1
Summary: DisplayAlert causes NSInvalidArgumentException in iOS 7.1
Alias: None
Product: Forms
Classification: Xamarin
Component: Forms ()
Version: 1.2.3
Hardware: PC Mac OS
: Normal normal
Target Milestone: ---
Assignee: Bugzilla
URL: https://github.com/xamarin/Duplo/issu...
Depends on:
Reported: 2014-10-13 13:49 UTC by Cody Beyer (MSFT)
Modified: 2015-01-18 03:56 UTC (History)
5 users (show)

Is this bug a regression?: ---
Last known good build:

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Description Cody Beyer (MSFT) 2014-10-13 13:49:24 UTC
Passing String.Empty to DisplayAlert as the Cancel overload causes an NSInvalidArgumentException.

The following code works on iOS 8, but throws the exception on iOS 7.1. Per https://bugzilla.xamarin.com/show_bug.cgi?id=21397 it appears that passing an empty string should be acceptable.  
	DisplayAlert("Feedback Accepted", "Thank you for submitting your feedback.","ok",string.Empty);

Steps to Reproduce: 

Open test case (https://www.dropbox.com/s/o9qnlxfqhcn1k1w/FormsActionSheetiPad.zip?dl=0)
Run in iOS 7.1 Simulator
Click button

Expected Result:

DisplayAlert appears

Actual Result:
NSInvalidArgumentException is thrown
Comment 1 Arpit Jha 2014-10-14 04:08:11 UTC
I have checked this issue and able to reproduce it.
I have tried following steps to reproduce it.
1.Create Xamarin Forms Application.
2.Add a class(.cs) and add button control.
3.Did following code on button click.

DisplayAlert("Feedback Accepted", "Thank you for submitting your

4.Run on ios 7.1 simulator.

I observed that getting an exception of "NSInvalidArgumentException " when call DisplayAlert on  button click event.It works fine with ios 8 

Screencast regarding Same:

Environment Info:
=== Xamarin Studio ===

Version 5.5 (build 227)
Installation UUID: 011d70a5-dede-428b-ab04-ef451c2e539d
 Mono 3.10.0 ((detached/47db868)
 GTK+ 2.24.23 (Raleigh theme)

 Package version: 310000019

=== Apple Developer Tools ===

Xcode 5.1 (5084)
Build 5B130a

=== Xamarin.Mac ===

Version: (Business Edition)

=== Xamarin.Android ===

Version: 4.18.0 (Business Edition)
Android SDK: /Users/MM/Desktop/android-sdk-macosx
 Supported Android versions:
  2.1    (API level 7)
  2.2    (API level 8)
  2.3    (API level 10)
  3.1    (API level 12)
  3.2    (API level 13)
  4.0    (API level 14)
  4.0.3  (API level 15)
  4.1    (API level 16)
  4.2    (API level 17)
  4.3    (API level 18)
  4.4    (API level 19)
  4.4.87 (API level 20)
  4.5    (API level 21)
Java SDK: /usr
java version "1.7.0_65"
Java(TM) SE Runtime Environment (build 1.7.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 24.65-b04, mixed mode)

=== Xamarin.iOS ===

Version: (Business Edition)
Hash: 959c1e4
Build date: 2014-10-03 00:25:37-0400

=== Build Information ===

Release ID: 505000227
Git revision: 7b721eeec7a2fa4c4f4de0ecd2aed4dc25edac95
Build date: 2014-10-02 15:53:38-04
Xamarin addins: 99ed56b428b31eba1efaace4d82188d6f334e6ca

=== Operating System ===

Mac OS X 10.9.5
Darwin MacMini.local 13.4.0 Darwin Kernel Version 13.4.0
    Sun Aug 17 19:50:11 PDT 2014
    root:xnu-2422.115.4~1/RELEASE_X86_64 x86_64
Comment 2 Jason Smith [MSFT] 2015-01-18 03:56:56 UTC
Fixed in 1.3.0