How can I use the async keywords in a project targeting.net 4.0

You want the Microsoft.Bcl.Async package. That’s a properly released, non-CTP package that is stable. This also requires VS2012 since an updated compiler is needed to understand async and await. In theory one could use older tools from VS2010 along with the older CTP library, I’d strongly recommend that you don’t – it has bugs and … Read more

What is the difference between Asynchronous calls and Callbacks

Very simply, a callback needn’t be asynchronous. http://docs.apigee.com/api-baas/asynchronous-vs-synchronous-calls Synchronous: If an API call is synchronous, it means that code execution will block (or wait) for the API call to return before continuing. This means that until a response is returned by the API, your application will not execute any further, which could be perceived by … Read more

Calling an async method from a constructor in Dart

Probably the best way to handle this is with a factory function, which calls a private constructor. In Dart, private methods start with an underscore, and “additional” constructors require a name in the form ClassName.constructorName, since Dart doesn’t support function overloading. This means that private constructors require a name, which starts with an underscore (MyComponent._create … Read more