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 d8b2991..a980eff 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/MainActivity.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/MainActivity.java
@@ -104,7 +104,7 @@ public class MainActivity extends BaseActivity implements Navigation.Callback {
     }
 
     private void syncNotes() {
-        if (!NetworkUtils.isNetworkAvailable(MainActivity.this)) {
+        if (!NetworkUtils.isNetworkAvailable()) {
             ToastUtils.showNetworkUnavailable(MainActivity.this);
             mSwipeRefresh.setRefreshing(false);
             return;
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 834d381..3056cf9 100644
--- a/app/src/main/java/org/houxg/leamonax/ui/NotePreviewActivity.java
+++ b/app/src/main/java/org/houxg/leamonax/ui/NotePreviewActivity.java
@@ -166,7 +166,7 @@ public class NotePreviewActivity extends BaseActivity implements EditorFragment.
 
     @OnClick(R.id.tv_revert)
     void revert() {
-        if (!NetworkUtils.isNetworkAvailable(this)) {
+        if (!NetworkUtils.isNetworkAvailable()) {
             ToastUtils.showNetworkUnavailable(this);
             return;
         }
diff --git a/app/src/main/java/org/houxg/leamonax/utils/NetworkUtils.java b/app/src/main/java/org/houxg/leamonax/utils/NetworkUtils.java
index c8cf277..28ba688 100644
--- a/app/src/main/java/org/houxg/leamonax/utils/NetworkUtils.java
+++ b/app/src/main/java/org/houxg/leamonax/utils/NetworkUtils.java
@@ -22,13 +22,13 @@ public class NetworkUtils {
         return cm.getActiveNetworkInfo();
     }
 
-    public static boolean isNetworkAvailable(Context context) {
-        NetworkInfo info = getActiveNetworkInfo(context);
+    public static boolean isNetworkAvailable() {
+        NetworkInfo info = getActiveNetworkInfo(Leamonax.getContext());
         return (info != null && info.isConnected());
     }
 
     public static void checkNetwork() throws NetworkUnavailableException {
-        if (!isNetworkAvailable(Leamonax.getContext())) {
+        if (!isNetworkAvailable()) {
             throw new NetworkUnavailableException();
         }
     }