diff --git a/common/Classes/UIViewController+Extend.h b/common/Classes/UIViewController+Extend.h
index 7fab500a..b186502c 100644
--- a/common/Classes/UIViewController+Extend.h
+++ b/common/Classes/UIViewController+Extend.h
@@ -36,6 +36,4 @@
 - (BOOL)checkNetworkStatus;
 
 - (void)popupTwoStepVerificationViewHandler:(void (^)(NSString *input,BOOL remember))handler;
-
-- (UIViewController *)topViewControllerIn:(UIViewController*)rootViewRootVC;
 @end
diff --git a/common/Classes/UIViewController+Extend.m b/common/Classes/UIViewController+Extend.m
index 714ef478..f23ec5de 100644
--- a/common/Classes/UIViewController+Extend.m
+++ b/common/Classes/UIViewController+Extend.m
@@ -236,25 +236,4 @@ - (BOOL)checkNetworkStatus
     return YES;
 }
 
-#pragma mark topViewController
-- (UIViewController *)topViewControllerIn:(UIViewController*)rootViewRootVC {
-    UIViewController *topVC;
-    topVC = [self findTopViewController:rootViewRootVC];
-    while (topVC.presentedViewController) {
-        topVC = [self findTopViewController:topVC.presentedViewController];
-    }
-    return topVC;
-}
-
-- (UIViewController *)findTopViewController:(UIViewController *)vc {
-    if ([vc isKindOfClass:[UINavigationController class]]) {
-        return [self findTopViewController:[(UINavigationController *)vc topViewController]];
-    } else if ([vc isKindOfClass:[UITabBarController class]]) {
-        return [self findTopViewController:[(UITabBarController *)vc selectedViewController]];
-    } else {
-        return vc;
-    }
-    return nil;
-}
-
 @end
diff --git a/seafile/SeafAppDelegate.h b/seafile/SeafAppDelegate.h
index 8ba970bf..a8dbf1d8 100644
--- a/seafile/SeafAppDelegate.h
+++ b/seafile/SeafAppDelegate.h
@@ -73,6 +73,7 @@ enum {
 - (void)stopSignificantChangeUpdates;
 - (void)checkBackgroundUploadStatus;
 
++ (UIViewController *)topViewController;
 + (void)checkOpenLink:(SeafFileViewController *)c;
 
 @end
diff --git a/seafile/SeafAppDelegate.m b/seafile/SeafAppDelegate.m
index d487a823..6ea46ade 100644
--- a/seafile/SeafAppDelegate.m
+++ b/seafile/SeafAppDelegate.m
@@ -681,4 +681,30 @@ - (void)onResp:(BaseResp *)resp {
     }
 }
 
+#pragma mark topViewController
++ (UIViewController *)topViewController {
+    SeafAppDelegate *delegate = (SeafAppDelegate*)[UIApplication sharedApplication].delegate;
+    return  [delegate topViewController];
+}
+
+- (UIViewController *)topViewController {
+    UIViewController *rootVC = [self.window rootViewController];
+    UIViewController *topVC = [self findTopViewController:rootVC];
+    while (topVC.presentedViewController) {
+        topVC = [self findTopViewController:topVC.presentedViewController];
+    }
+    return topVC;
+}
+
+- (UIViewController *)findTopViewController:(UIViewController *)vc {
+    if ([vc isKindOfClass:[UINavigationController class]]) {
+        return [self findTopViewController:[(UINavigationController *)vc topViewController]];
+    } else if ([vc isKindOfClass:[UITabBarController class]]) {
+        return [self findTopViewController:[(UITabBarController *)vc selectedViewController]];
+    } else {
+        return vc;
+    }
+    return nil;
+}
+
 @end
diff --git a/seafile/SeafFileViewController.m b/seafile/SeafFileViewController.m
index dab57458..dd29c39b 100644
--- a/seafile/SeafFileViewController.m
+++ b/seafile/SeafFileViewController.m
@@ -674,9 +674,7 @@ - (void)showSheetWithTitles:(NSArray*)titles andFromView:(id)view
 
         [actionSheet showFromPoint:point inView:self.navigationController.view arrowDirection:SFActionSheetArrowDirectionTop animated:YES];
     } else {
-        UIViewController *topVC = [self topViewControllerIn:[[[[UIApplication sharedApplication] delegate] window] rootViewController]];
-        
-        [actionSheet showInView:topVC.view.window animated:YES];
+        [actionSheet showInView:[SeafAppDelegate topViewController].view.window animated:YES];
     }
 }