diff --git a/app/src/main/java/com/example/childguard/HomeFragment.java b/app/src/main/java/com/example/childguard/HomeFragment.java
index 9058f94..fab5664 100644
--- a/app/src/main/java/com/example/childguard/HomeFragment.java
+++ b/app/src/main/java/com/example/childguard/HomeFragment.java
@@ -80,6 +80,12 @@ public class HomeFragment extends Fragment implements OnEventListener {
         super.onResume();
         Log.d("HomeFragment", "onResume: called");
         this.updateUiState(getIsInCarLocal());
+        this.updateBluetoothSituation(isBluetoothConnected());
+    }
+
+    private boolean isBluetoothConnected() {
+        SharedPreferences pref = requireActivity().getSharedPreferences("Bluetooth_situation", requireActivity().MODE_PRIVATE);
+        return pref.getBoolean("status", false);
     }
 
     private boolean getIsInCarLocal() {
@@ -174,17 +180,5 @@ public class HomeFragment extends Fragment implements OnEventListener {
 
         return updateUiState(isInCar);
     }
-
-    @Override
-    public void onEvent2(boolean BluetoothConnect) {
-        return;
-    }
-
-
-    @Override
-    public boolean onEvent2(Boolean BluetoothConnect) {//Bluetoothの接続切断を受け取ってupdateBluetoothSituation()に渡す
-        updateBluetoothSituation(BluetoothConnect);
-        return false;
-    }
 }
 
diff --git a/app/src/main/java/com/example/childguard/MainActivity.java b/app/src/main/java/com/example/childguard/MainActivity.java
index 6947e3b..f96d300 100644
--- a/app/src/main/java/com/example/childguard/MainActivity.java
+++ b/app/src/main/java/com/example/childguard/MainActivity.java
@@ -429,9 +429,7 @@ public class MainActivity extends AppCompatActivity {
             if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) {
                 //Do something if connected
                 //Bluetoothデバイスが接続されたときの処理
-                e.putBoolean("change", true);
-                e.apply();
-                changeBluetooth();//HomeFragmentの表示を接続にする
+                changeBluetooth(true);
                 Log.d("BT", "Device connected");
 
                 Log.d("BT_Judge", "Registered: " + registeredId);
@@ -452,9 +450,7 @@ public class MainActivity extends AppCompatActivity {
 
                 //Do something if disconnected
                 //デバイスが切断されたときの処理
-                e.putBoolean("change", false);
-                e.apply();
-                changeBluetooth();//HomeFragmentの表示を切断にする
+                changeBluetooth(false);
                 if (deviceHardwareAddress.equals(registeredId)) {
                     // 5分待機する
                     Handler handler = new Handler();
@@ -473,12 +469,8 @@ public class MainActivity extends AppCompatActivity {
         }
     };
 
-    public void changeBluetooth(){
-        SharedPreferences pref=getSharedPreferences("Bluetooth_situation",MODE_PRIVATE);
-        SharedPreferences.Editor e=pref.edit();
-        Boolean BluetoothConnect = pref.getBoolean("change", false);
-        Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.fragmentContainerView);
-        ((HomeFragment) fragment).onEvent2(BluetoothConnect);
+    public void changeBluetooth(boolean actual){
+        getSharedPreferences("Bluetooth_situation",MODE_PRIVATE).edit().putBoolean("status",actual).apply();
     }
 }
 
diff --git a/app/src/main/java/com/example/childguard/OnEventListener.java b/app/src/main/java/com/example/childguard/OnEventListener.java
index 1782b5f..8bf8757 100644
--- a/app/src/main/java/com/example/childguard/OnEventListener.java
+++ b/app/src/main/java/com/example/childguard/OnEventListener.java
@@ -3,8 +3,4 @@ package com.example.childguard;
 public interface OnEventListener {
 
     boolean onEvent(boolean state);
-
-    void onEvent2(boolean BluetoothConnect);
-
-    boolean onEvent2(Boolean BluetoothConnect);
 }