diff --git a/app/src/main/java/com/xypower/mpapp/MainActivity.java b/app/src/main/java/com/xypower/mpapp/MainActivity.java
index 98b8c99c..8cde7a38 100644
--- a/app/src/main/java/com/xypower/mpapp/MainActivity.java
+++ b/app/src/main/java/com/xypower/mpapp/MainActivity.java
@@ -57,8 +57,8 @@ public class MainActivity extends AppCompatActivity {
     }
 
     public static final int MAX_LOG_LINES = 480;
+    public static final int MIN_LOG_LINES = 120;
 
-    private int mLines = 0;
     private ActivityMainBinding binding;
 
     private Handler mHandler = null;
@@ -141,27 +141,6 @@ public class MainActivity extends AppCompatActivity {
             @Override
             public void handleMessage(@NonNull Message msg) {
                 switch (msg.what) {
-                    case MicroPhotoService.MSG_WHAT_LOG: {
-                        String log = (String) msg.obj;
-                        binding.logs.append(log);
-
-                        // Reply
-                        // Messenger clientMessenger = msg.replyTo;
-                        // Message replyMessage = Message.obtain(null, 2);
-                        // 设置回复消息中的数据
-                        Bundle replyData = new Bundle();
-                        replyData.putString("key", "reply value");
-                        // replyMessage.setData(replyData);
-                        /*
-                        try {
-                            clientMessenger.send(replyMessage);
-                        } catch (RemoteException e) {
-                            e.printStackTrace();
-                        }
-
-                         */
-                    }
-                    break;
                     case MSG_WHAT_LOG_OBSERVER:
                     {
                         byte[] bytes = (byte[])msg.obj;
@@ -170,35 +149,14 @@ public class MainActivity extends AppCompatActivity {
                         try {
                             log = new String(bytes, 0, bytesRead, "UTF-8");
                         } catch (Exception e) {
+                            e.printStackTrace();
                         }
                         if (log != null) {
-
-                            long lines = log.chars().filter(ch -> ch == '\n').count();
-                            mLines += lines;
-                            if (mLines + lines > MAX_LOG_LINES) {
-                                int excessLineNumber = MAX_LOG_LINES / 2;
-
-                                int eolIndex = -1;
-                                CharSequence charSequence = binding.logs.getText();
-                                for(int i = 0; i < excessLineNumber; i++) {
-                                    do {
-                                        eolIndex++;
-                                    } while(eolIndex < charSequence.length() && charSequence.charAt(eolIndex) != '\n');
-                                }
-                                if (eolIndex < charSequence.length()) {
-                                    binding.logs.getEditableText().delete(0, eolIndex+1);
-                                }
-                                mLines -= excessLineNumber;
-                            }
-
                             binding.logs.append(log);
-
-                            // if (line > 9) {//超出屏幕自动滚动显示(9是当前页面显示的最大行数)
                             int offset = mLines * binding.logs.getLineHeight();
                             if (offset > binding.logs.getHeight()) {
                                 binding.logs.scrollTo(0, offset - binding.logs.getHeight() + binding.logs.getLineHeight());
                             }
-                            // }
                         }
                     }
                     break;
@@ -567,12 +525,31 @@ public class MainActivity extends AppCompatActivity {
         // call the superclass method first
         super.onResume();
 
-        String logFilePath = MicroPhotoContext.buildAppDir(this.getApplicationContext());
-        logFilePath += "logs/log.txt";
-
-        mLogFileObserver = new LogFileObserver(logFilePath);
-        mLogFileObserver.startWatching();
-        Log.i(TAG, "Log Observer Started");
+        try {
+            String logFilePath = MicroPhotoContext.buildAppDir(this.getApplicationContext());
+            logFilePath += "logs/log.txt";
+
+            mLogFileObserver = new LogFileObserver(logFilePath);
+            mLogFileObserver.startWatching();
+            Log.i(TAG, "Log Observer Started");
+
+            int lines = binding.logs.getLineCount();
+            if (lines > MAX_LOG_LINES) {
+                int excessLineNumber = lines - MIN_LOG_LINES;
+                int eolIndex = -1;
+                CharSequence charSequence = binding.logs.getText();
+                for (int i = 0; i < excessLineNumber; i++) {
+                    do {
+                        eolIndex++;
+                    } while (eolIndex < charSequence.length() && charSequence.charAt(eolIndex) != '\n');
+                }
+                if (eolIndex < charSequence.length()) {
+                    binding.logs.getEditableText().delete(0, eolIndex + 1);
+                }
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
     }
 
     @Override
@@ -580,16 +557,19 @@ public class MainActivity extends AppCompatActivity {
         // call the superclass method first
         super.onPause();
 
-        if (mLogFileObserver != null) {
-            mLogFileObserver.stopWatching();
-            mLogFileObserver = null;
-            Log.i(TAG, "Log Observer Stopped");
+        try {
+            if (mLogFileObserver != null) {
+                mLogFileObserver.stopWatching();
+                mLogFileObserver = null;
+                Log.i(TAG, "Log Observer Stopped");
+            }
+        } catch (Exception e) {
+            e.printStackTrace();
         }
     }
 
     @Override
     protected void onDestroy() {
-
         super.onDestroy();
     }