Question: Now I have something like this:

```
<input type="text" ng-model="cell.location">

```

What I want is while you put 'ABC' in this field, this field will become disabled status, I know I can put a boolean param to control it via its controller.

However what I expect is something like this:

```
<input type="text" ng-disabled="{{cell.location = 'ABC'}}" ng-model="cell.location">

```

Which is clearer and simpler, unfortunately this approach doesn't work as expected, it will assign 'ABC' to this field rather than disable it. is that possible to implement in this kind of way? 

Thanks.

Answer: 
Found this error at Release build, yet not in Debug build.

For Xamarin + VS, TLS 1.2 can be set in Android Project Properties (right click on your Android Project > Properties on bottom) > Android Options > scroll to bottom, click Advance > bottom, SSL/TLS Implementations. There you found Native TLS 1.2+.
I'm not aware of a generic cross-platform Xamarin solution for this.

Xamarin has an option to support TLS 1.2 for iOS9 with App Transport Security ( <https://developer.xamarin.com/guides/ios/platform_features/introduction_to_ios9/ats/> ) :

> 
> Any connection made with NSUrlConnection, CFUrl or NSUrlSession will
>  use ATS by default in apps built for iOS 9 and OS X 10.11 (El
>  Capitan).
>  ATS will enforce the following requirements for all internet
>  connections: All connection ciphers must be using forward secrecy. The
>  Transport Layer Security (TLS) protocol must be version 1.2 or
>  greater. At least a SHA256 fingerprint with either a 2048 bit or
>  greater RSA key, or a 256 bit or greater Elliptic-Curve (ECC) key must
>  be used for all certificates.
> 
> 
> 

There is a community push to fill this gap since April 2014 at <https://xamarin.uservoice.com/forums/144858-xamarin-platform-suggestions/suggestions/5758129-implement-tls-1-2> .