diff --git a/app/src/main/java/com/xypower/mpapp/MainActivity.java b/app/src/main/java/com/xypower/mpapp/MainActivity.java
index 47b94a97..009dc428 100644
--- a/app/src/main/java/com/xypower/mpapp/MainActivity.java
+++ b/app/src/main/java/com/xypower/mpapp/MainActivity.java
@@ -73,7 +73,7 @@ public class MainActivity extends AppCompatActivity {
         Date date = new Date(BuildConfig.BUILD_TIMESTAMP);
         SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm");
         String caption = "MP";
-        switch (getCustomAppId()) {
+        switch (MicroPhotoService.getCustomAppId()) {
             case 1:
                 caption = "RP";
                 break;
@@ -640,6 +640,6 @@ public class MainActivity extends AppCompatActivity {
     }
 
 
-    private native int getCustomAppId();
+
 
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java b/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java
index 15ea34cf..87bd2016 100644
--- a/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java
+++ b/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java
@@ -1681,6 +1681,8 @@ cellSignalStrengthGsm.getDbm();
     public static native long requestPowerControl(int type);
     public static native boolean releasePowerControl(long powerControlHandle);
 
+    public static native int getCustomAppId();
+
     ////////////////////////GPS////////////////////
     // private static final String GPS_LOCATION_NAME = android.location.LocationManager.GPS_PROVIDER;
     private LocationManager mLocationManager;