问题
so from what i gather, Socket connections are neither serializable or parcelable, but i need to pass a bluetooth connection to another Activity. i do not want to write a Service as a middle man, so please don't post this as a solution. i've heard that there is a way to pass these types of Objects using a custom Application interface, but i cannot, for the life of me, find a working example of this. i've seen plenty of documentation that says something to the effect of "this is possible" but nothing showing how to do it.
回答1:
Define your app class:
class MyApplication extends Application{
// your fields here
}
Add name attribute to app manifest.
<application android:name=".MyApplication" ../>
Use it in Activity:
MyApplication myapp = (MyApplication) getApplication();
来源：https://stackoverflow.com/questions/5158758/how-to-pass-a-bluetooth-socket-to-another-activity-using-application-interface