Solving the Infamous Flutter android.view.ViewRootImpl.performTraversals() Problem: A Step-by-Step Guide

Are you tired of encountering the frustrating android.view.ViewRootImpl.performTraversals() problem in your Flutter app? You’re not alone! This notorious issue has plagued many developers, causing hours of hair-pulling and coffee-fueled late-night coding sessions. Fear not, dear Flutter enthusiasts, for we’ve got you covered. In this comprehensive guide, we’ll delve into the depths of this problem and provide a clear, step-by-step walkthrough to help you overcome this pesky error once and for all.

What is the android.view.ViewRootImpl.performTraversals() Problem?

The android.view.ViewRootImpl.performTraversals() problem typically manifests as a crash or ANR (Application Not Responding) error in your Flutter app on Android devices. It occurs when the Flutter engine attempts to perform a traversal on a view that has already been detached or removed from the view hierarchy. This can happen due to various reasons, such as:

• Incorrect widget tree management
• Improper use of navigation or routing
• Conflict with native Android components

Symptoms and Error Messages

If you’re experiencing the android.view.ViewRootImpl.performTraversals() problem, you might encounter the following symptoms or error messages:

E/AndroidRuntime( 5413): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
E/AndroidRuntime( 5413):    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1116)
E/AndroidRuntime( 5413):    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:961)
E/AndroidRuntime( 5413):    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4866)
E/AndroidRuntime( 5413):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
E/AndroidRuntime( 5413):    at android.view.Choreographer.doCallbacks(Choreographer.java:580)
E/AndroidRuntime( 5413):    at android.view.Choreographer.doFrame(Choreographer.java:550)
E/AndroidRuntime( 5413):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
E/AndroidRuntime( 5413):    at android.os.Handler.handleCallback(Handler.java:739)
E/AndroidRuntime( 5413):    at android.os.Handler.dispatchMessage(Handler.java:95)
E/AndroidRuntime( 5413):    at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime( 5413):    at android.app.ActivityThread.main(ActivityThread.java:5135)
E/AndroidRuntime( 5413):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 5413):    at java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime( 5413):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
E/AndroidRuntime( 5413):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610)
E/AndroidRuntime( 5413):    at dalvik.system.NativeStart.main(Native Method)

Step-by-Step Solution

Now that we’ve identified the problem, let’s dive into the solution. Follow these steps to resolve the android.view.ViewRootImpl.performTraversals() problem in your Flutter app:

1. Review Your Navigation and Routing

   Ensure that you’re using the correct navigation and routing mechanisms in your Flutter app. Avoid using native Android components or fragments, as they can interfere with the Flutter engine. Instead, use Flutter’s built-in navigation and routing widgets, such as MaterialApp, Navigator, and Route.

2. Check for Widget Tree Inconsistencies

   Verify that your widget tree is correctly managed and consistent. Avoid adding or removing widgets from the tree while the app is in the background or during navigation transitions. Use tools like the Flutter Inspector or Android Studio’s layout inspector to visualize your widget tree and identify potential issues.

3. Use the Correct Thread for View Manipulation

   Ensure that you’re performing view manipulation on the correct thread. In Flutter, all view-related operations should be executed on the main thread (also known as the UI thread). Use WidgetsBinding.instance.addPostFrameCallback() or Future.delayed() to schedule tasks on the main thread.

   
   WidgetsBinding.instance.addPostFrameCallback((_) {
     // Perform view manipulation here
   });
   
   

4. Avoid Conflicting Native Android Components

   Identify and remove any conflicting native Android components that might be causing the issue. Check your app’s AndroidManifest.xml file and remove any unnecessary or duplicate declarations.

5. Update Your Flutter and Android Dependencies

   Ensure that your Flutter and Android dependencies are up-to-date. Run flutter pub get and flutter pub upgrade to update your dependencies to the latest versions.

6. Clear the Android Debug Bridge (ADB) Cache

   Sometimes, the ADB cache can become corrupted, causing issues like the android.view.ViewRootImpl.performTraversals() problem. Clear the ADB cache by running the following command:

   
   adb kill-server
   adb start-server
   
   

7. Test and Debug Your App

   Thoroughly test and debug your app to identify and fix any remaining issues. Use tools like the Flutter Debugger, Android Studio’s built-in debugger, or third-party libraries like Flutter Debugger to help you identify and fix problems.

Conclusion

The android.view.ViewRootImpl.performTraversals() problem can be frustrating, but by following the steps outlined in this guide, you should be able to resolve the issue and get your Flutter app running smoothly again. Remember to stay vigilant and keep your dependencies up-to-date to avoid any future problems.

Troubleshooting Tips
Review your navigation and routing mechanisms
Check for widget tree inconsistencies
Use the correct thread for view manipulation
Avoid conflicting native Android components
Update your Flutter and Android dependencies
Clear the Android Debug Bridge (ADB) cache
Test and debug your app thoroughly

By following these troubleshooting tips and the step-by-step solution outlined in this guide, you’ll be well on your way to resolving the android.view.ViewRootImpl.performTraversals() problem and creating a robust, error-free Flutter app.

Frequently Asked Question

Got stuck with the Flutter android.view.ViewRootImpl.performTraversals() problem? Don’t worry, we’ve got you covered! Here are some frequently asked questions and answers to help you resolve this frustrating issue.