导航：[首页]->[wingui]->[Windows 8学习笔记2 Promise]
One way to do this is to have a function execute at a later time, as with event handlers, which are invoked after another call has raised an event. Callback functions are another kind of asynchronous processing, because they call back into the code that initiated the process.
Problems when using asynchronous programming
You can also group multiple promises. For example, you can use the join function run multiple asynchronous operations that call several web services and then aggregate the results.
Handle errors with promises