Question

I am new to MonoTouch iPhone apps, when i am trying to run Social Framework Demo from Xamarin samples , clicking on any button crashes the application with unhandled exception, anybody please help me

MonoDevelop 3.0.4.7

Installation UUID: d9012fd4-f121-4a57-839d-50ccdf232e64

Runtime:

Mono 2.10.9 (tarball)
GTK 2.24.10
GTK# (2.12.0.0)
Package version: 210090011

Apple Developer Tools:

 Xcode 4.2.1 (834)
 Build 4D502

Mono for Android: 4.2.7

Android SDK: /Users/ravichandra/Library/Developer/Xamarin/android-sdk-mac_x86

Supported Android versions:
    2.1   (API level 7)
    2.2   (API level 8)
    2.3   (API level 10)
    3.1   (API level 12)
    4.0   (API level 14)
    4.0.3 (API level 15)

Java SDK: /usr
Monotouch: 6.0.0

Build information:

Release ID: 30004007
Git revision: ea0108260c6a376ecaeffcdb7d03387bd51edda3
Build date: 2012-09-17 14:09:17+0000
Xamarin addins: ec43fd5cb223ead4234a9858d1b56eef03dad53a-dirty

Operating System:

Mac OS X 10.7.5
Darwin Ravi-Chandras-iMac.local 11.4.2 Darwin Kernel Version 11.4.2
    Thu Aug 23 16:25:48 PDT 2012
    root:xnu-1699.32.7~1/RELEASE_X86_64 x86_64

[ERROR] FATAL UNHANDLED EXCEPTION: System.ArgumentNullException: Argument cannot be null.
Parameter name: serviceType

at MonoTouch.Social.SLComposeViewController.IsAvailable (MonoTouch.Foundation.NSString serviceType) [0x0000c] in /Developer/MonoTouch/Source/monotouch/src/Social/SLComposeViewController.g.cs:93

at MonoTouch.Social.SLComposeViewController.IsAvailable (SLServiceKind serviceKind) [0x00000] in /Developer/MonoTouch/Source/monotouch/src/Social/SLComposeViewController.cs:25

at SocialFrameworkDemo.SocialFrameworkDemoViewController.m__1 (System.Object , System.EventArgs ) [0x00000] in /Users/ravichandra/Downloads/SocialFrameworkDemo
2/SocialFrameworkDemo/SocialFrameworkDemoViewController.cs:52

at MonoTouch.UIKit.UIControlEventProxy.Activated () [0x00000] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIControl.cs:30

at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication:UIApplicationMain (int,string[],intptr,intptr)
at MonoTouch.UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0004c] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIApplication.cs:38

at SocialFrameworkDemo.Application.Main (System.String[] args) [0x00000] in /Users/ravichandra/Downloads/SocialFrameworkDemo 2/SocialFrameworkDemo/Main.cs:17

Answer 1

Xcode 4.2.1 (834)

The new Social framework is available on iOS 6.0 (and later). This SDK is only available if you install Xcode 4.5 (or later).

Without it you’re missing the required libraries to support the new features. In this case you’re getting some missing strings as null values – and that throws an exception in the sample.