java.lang.NullPointerException: Attempt to invoke virtual method 'android.support.v4.provider.DocumentFile[] android.support.v4.provider.DocumentFile.listFiles()' on a null object reference
at com.givemefive.ble.BLEActivityMi8Pro.readAllWfFiles(BLEActivityMi8Pro.java:1220)
at com.givemefive.ble.BLEActivityMi8Pro$8.run(BLEActivityMi8Pro.java:1207)
at java.lang.Thread.run(Thread.java:1012)
以上是崩溃代码,求解决
at com.givemefive.ble.BLEActivityMi8Pro.readAllWfFiles(BLEActivityMi8Pro.java:1220)
at com.givemefive.ble.BLEActivityMi8Pro$8.run(BLEActivityMi8Pro.java:1207)
at java.lang.Thread.run(Thread.java:1012)
以上是崩溃代码,求解决