diff --git a/Classes_cocos/UIViewController+Wallet.mm b/Classes_cocos/UIViewController+Wallet.mm
index f47daa7..961ada3 100644
--- a/Classes_cocos/UIViewController+Wallet.mm
+++ b/Classes_cocos/UIViewController+Wallet.mm
@@ -23,17 +23,15 @@
     if ([QRCodeReader supportsMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]]) {
         static QRCodeReaderViewController *vc = nil;
         static dispatch_once_t onceToken;
-
-//        dispatch_once(&onceToken, ^{
-//
-//        });
         
         dispatch_async(dispatch_get_main_queue(), ^{
             // if we are active again, we don't need to do this anymore
-            QRCodeReader *reader = [QRCodeReader readerWithMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];
-            vc = [QRCodeReaderViewController readerWithCancelButtonTitle:@"Cancel" codeReader:reader startScanningAtLoad:YES showSwitchCameraButton:YES showTorchButton:YES];
-            vc.modalPresentationStyle = UIModalPresentationFormSheet;
-
+            if (vc == nil) {
+                QRCodeReader *reader = [QRCodeReader readerWithMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];
+                vc = [QRCodeReaderViewController readerWithCancelButtonTitle:@"Cancel" codeReader:reader startScanningAtLoad:YES showSwitchCameraButton:YES showTorchButton:YES];
+                vc.modalPresentationStyle = UIModalPresentationFormSheet;
+            }
+            
             [vc setCompletionWithBlock:^(NSString *resultAsString) {
                 NSLog(@"Completion with result: %@", resultAsString);
                 [self dismissViewControllerAnimated:YES completion:^{
diff --git a/Unity-iPhone.xcodeproj/project.xcworkspace/xcuserdata/zhl.xcuserdatad/UserInterfaceState.xcuserstate b/Unity-iPhone.xcodeproj/project.xcworkspace/xcuserdata/zhl.xcuserdatad/UserInterfaceState.xcuserstate
index 232f894..be38883 100644
Binary files a/Unity-iPhone.xcodeproj/project.xcworkspace/xcuserdata/zhl.xcuserdatad/UserInterfaceState.xcuserstate and b/Unity-iPhone.xcodeproj/project.xcworkspace/xcuserdata/zhl.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/Unity-iPhone.xcodeproj/xcuserdata/zhl.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist b/Unity-iPhone.xcodeproj/xcuserdata/zhl.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
index 1581fb6..d70068c 100644
--- a/Unity-iPhone.xcodeproj/xcuserdata/zhl.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
+++ b/Unity-iPhone.xcodeproj/xcuserdata/zhl.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
@@ -206,8 +206,8 @@
             filePath = "Classes_cocos/UIViewController+Wallet.mm"
             startingColumnNumber = "9223372036854775807"
             endingColumnNumber = "9223372036854775807"
-            startingLineNumber = "46"
-            endingLineNumber = "46"
+            startingLineNumber = "44"
+            endingLineNumber = "44"
             landmarkName = "-scanQRCode:"
             landmarkType = "7">
          </BreakpointContent>