< manifest xmlns: android = "http://schemas.android.com/apk/res/android" package= "com.z.steven.xchat" > < uses-permission android :name= "android.permission.READ_PHONE_STATE" /> < application ... 申请 权限: if (ContextCompat. checkSelfPermission ( this , Manifest.permission. READ_PHONE_STATE ) != PackageManager. PERMISSION_GRANTED ) { // 申请 WRITE_EXTERNAL_STORAGE 权限 // ActivityCompat. requestPermissions ( this , new String[]{Manifest.permission. READ_PHONE_STATE }, CONTEXT_INCLUDE_CODE ); }