//如果主线程使用了子线程的looper，那么就会报错
mHandler = new Handler(myThread.looper);
Attempt to read from field 'android.os.MessageQueue android.os.Looper.mQueue' on a null object refer
2019-10-08 17:36:39.892 12698-12698/bjpkten.handler E/AndroidRuntime: FATAL EXCEPTION: mainProcess: bjpkten.handler, PID: 12698java.lang.RuntimeException: Unable to start activity ComponentInfo{bjpkten.handler/bjpkten.handler.MainActivity}: java.lang.NullPointerException: Attempt to read from field 'android.os.MessageQueue android.os.Looper.mQueue' on a null object referenceat android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)at android.app.servertransaction.TransactionExecutor.executeCallbacks