How do I know if Looper is running?… here is a solution to the problem.
How do I know if Looper is running?
Sometimes I find this anomaly :
Cannot create a handler inside a thread that has not yet called Looper.prepare().
How do I know if Looper.myLooper() calls prepare?
ps – my English is not good
Solution
If you call Looper.myLooper(), it returns null if prepare has not been called. To view the source:
http://androidxref.com/5.1.1_r6/xref/frameworks/base/core/java/android/os/Looper.java