Handler messaging mechanism in Android

Why should I refer to the message mechanism?

1:ANR (Application not response) application unresponsive main thread (UI thread)

2: If a time-consuming operation occurs in the main thread, it causes the ANR (such as linking the network, copying large data) Thread.Sleep ()

3: Avoid the ANR you can take the time-consuming operation into a child thread and it's your new thread.

4:android4.0 after Google forced to require the link network can not be accessed in the main thread

5: Only the main thread (UI thread) can update the UI, note: Toast is a view, and you cannot update the UI on a child thread

　　

　　　　Handler Steps to use:

　　　

　　

Handler messaging mechanism in Android