diff --git a/app/src/main/java/org/houxg/leamonax/ui/MainActivity.java b/app/src/main/java/org/houxg/leamonax/ui/MainActivity.java
index 10c8c3d..7c457b9 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/MainActivity.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/MainActivity.java
@@ -93,9 +93,9 @@ public class MainActivity extends BaseActivity implements NotebookAdapter.Notebo
         CrashReport.setUserId(AccountService.getCurrent().getUserId());
         if (savedInstanceState == null) {
             mNoteFragment = NoteFragment.newInstance(getIntent().getBooleanExtra(EXT_SHOULD_RELOAD, false));
-            getFragmentManager().beginTransaction().add(R.id.container, mNoteFragment, TAG_NOTE_FRAGMENT).commit();
+            getSupportFragmentManager().beginTransaction().add(R.id.container, mNoteFragment, TAG_NOTE_FRAGMENT).commit();
         } else {
-            mNoteFragment = (NoteFragment) getFragmentManager().findFragmentByTag(TAG_NOTE_FRAGMENT);
+            mNoteFragment = (NoteFragment) getSupportFragmentManager().findFragmentByTag(TAG_NOTE_FRAGMENT);
         }
         mNoteFragment.setSyncFinishListener(this);
         mEmailTv.setText(AccountService.getCurrent().getEmail());
diff --git a/app/src/main/java/org/houxg/leamonax/ui/NoteFragment.java b/app/src/main/java/org/houxg/leamonax/ui/NoteFragment.java
index 758600a..2ac782d 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/NoteFragment.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/NoteFragment.java
@@ -2,10 +2,10 @@ package org.houxg.leamonax.ui;
 
 
 import android.app.AlertDialog;
-import android.app.Fragment;
 import android.content.DialogInterface;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
 import android.support.v4.widget.SwipeRefreshLayout;
 import android.support.v7.widget.DefaultItemAnimator;
 import android.support.v7.widget.LinearLayoutManager;
diff --git a/app/src/main/java/org/houxg/leamonax/ui/NotePreviewActivity.java b/app/src/main/java/org/houxg/leamonax/ui/NotePreviewActivity.java
index 062500b..180fc61 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/NotePreviewActivity.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/NotePreviewActivity.java
@@ -60,7 +60,7 @@ public class NotePreviewActivity extends BaseActivity implements EditorFragment.
         mNote = AppDataBase.getNoteByLocalId(noteLocalId);
 
         mEditorFragment = EditorFragment.getNewInstance(mNote.isMarkDown(), false);
-        getFragmentManager().beginTransaction().add(R.id.container, mEditorFragment).commit();
+        getSupportFragmentManager().beginTransaction().add(R.id.container, mEditorFragment).commit();
     }
 
     public static Intent getOpenIntent(Context context, long noteLocalId) {
diff --git a/app/src/main/java/org/houxg/leamonax/ui/edit/EditorFragment.java b/app/src/main/java/org/houxg/leamonax/ui/edit/EditorFragment.java
index 2bdc976..b51bfd8 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/edit/EditorFragment.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/edit/EditorFragment.java
@@ -2,12 +2,12 @@ package org.houxg.leamonax.ui.edit;
 
 
 import android.app.Activity;
-import android.app.Fragment;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
 import android.support.v4.view.GravityCompat;
 import android.text.TextUtils;
 import android.util.Log;
@@ -97,6 +97,12 @@ public class EditorFragment extends Fragment implements Editor.EditorListener {
         return fragment;
     }
 
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+
+    }
+
     @Override
     public void onAttach(Activity context) {
         super.onAttach(context);
diff --git a/app/src/main/java/org/houxg/leamonax/ui/edit/NoteEditActivity.java b/app/src/main/java/org/houxg/leamonax/ui/edit/NoteEditActivity.java
index bb5e106..b483434 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/edit/NoteEditActivity.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/edit/NoteEditActivity.java
@@ -1,12 +1,11 @@
 package org.houxg.leamonax.ui.edit;
 
-import android.app.Fragment;
-import android.app.FragmentManager;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-import android.support.v13.app.FragmentPagerAdapter;
+import android.support.v4.app.Fragment;
+import android.support.v4.app.FragmentPagerAdapter;
 import android.support.v7.widget.Toolbar;
 import android.text.TextUtils;
 import android.util.Log;
@@ -65,12 +64,12 @@ public class NoteEditActivity extends BaseActivity implements EditorFragment.Edi
         initToolBar((Toolbar) findViewById(R.id.toolbar), true);
         mPager = (LeaViewPager) findViewById(R.id.pager);
         mPager.setPagingEnabled(false);
-        mPager.setAdapter(new SectionAdapter(getFragmentManager()));
+        mPager.setAdapter(new SectionAdapter(getSupportFragmentManager()));
         mPager.setOffscreenPageLimit(2);
 
         if (savedInstanceState != null) {
-            mEditorFragment = (EditorFragment) getFragmentManager().findFragmentByTag(savedInstanceState.getString(TAG_EDITOR));
-            mSettingsFragment = (SettingFragment) getFragmentManager().findFragmentByTag(savedInstanceState.getString(TAG_SETTING));
+            mEditorFragment = (EditorFragment) getSupportFragmentManager().findFragmentByTag(savedInstanceState.getString(TAG_EDITOR));
+            mSettingsFragment = (SettingFragment) getSupportFragmentManager().findFragmentByTag(savedInstanceState.getString(TAG_SETTING));
         }
 
         long noteLocalId = getIntent().getLongExtra(EXT_NOTE_LOCAL_ID, -1);
@@ -326,7 +325,8 @@ public class NoteEditActivity extends BaseActivity implements EditorFragment.Edi
 
     private class SectionAdapter extends FragmentPagerAdapter {
 
-        public SectionAdapter(FragmentManager fm) {
+
+        public SectionAdapter(android.support.v4.app.FragmentManager fm) {
             super(fm);
         }
 
diff --git a/app/src/main/java/org/houxg/leamonax/ui/edit/SettingFragment.java b/app/src/main/java/org/houxg/leamonax/ui/edit/SettingFragment.java
index c7f7d11..a66d827 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/edit/SettingFragment.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/edit/SettingFragment.java
@@ -1,10 +1,10 @@
 package org.houxg.leamonax.ui.edit;
 
 
-import android.app.Fragment;
 import android.graphics.Color;
 import android.os.Bundle;
 import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
 import android.text.Editable;
 import android.text.Spanned;
 import android.text.TextUtils;