uni-app real phone debugging

Your error may be caused by the css style of the vant ui not loading properly. You can try to check that the vant ui is being properly introduced into your project and that the styles and components it provides are being used.

install vant-ui component library
npm uninstall vant
npm install vant- 5
npm run clear

Dependency uninstallation re-install some versions are different, error

Is there an H5 userAgent function - Determine whether the device is IOS?

Refer to GPT and own thinking, according to the Uncaught TypeError message: Cannot read property 'userAgent" of undefined, the problem may be due to some reason the system cannot get the device's userAgent information. This may be because some plug-in or script modifies system variables while executing, causing this error. It is recommended that you try the following steps:

1 Check if you are using any plug-ins or scripts in your code that might cause this problem, such as polyfill for some browsers, custom User-Agent, and so on. You can try to comment out or disable these plug-ins or scripts to see if the problem persists.

2 Check whether the system or browser is abnormal or infected with viruses. Try using anti-virus software or clearing your browser cache, and restart your device to see if the problem is resolved.

3 If the above steps do not resolve the problem, try to reinstall vant and clean the cache of uni-app to eliminate potential conflicts or cache issues. You can try running the following command:

npm uninstall vant
npm install vant
npm run clear

If this still doesn't work, try
1 Try upgrading vant to the latest version and see if a new version fixes the problem.

2 Check whether other code or files introduce conflicting vant versions. You can try using the npm ls vant command to see all the dependent vant versions in your project. If multiple versions of vant exist at the same time, a conflict may occur. You can uninstall all conflicting versions except one.

3 Check whether any other libraries or frameworks conflict with vant. Try disabling some of the libraries or frameworks that might be causing the conflict and see if the problem can be resolved.

4 Try using a debugging tool such as console.log to locate the location of the code where the problem is. This can help resolve the problem faster.
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Check to see if there is node_modules in the root directory. If there are any, delete them and execute npm install. If not, execute npm install and then restart the project.

The following answers are based on ChatGPT and GISer Liu:

This problem may be caused by the incompatibility between the uni-app version and the vant-ui version you are using.

• You can try to upgrade uni-app and vant-ui to the latest version, or downgrade uni-app and vant-ui to compatible versions. For detailed operation methods, refer to the official documents or relevant community discussions. Alternatively, you can try removing the node_modules folder and reinstalling dependencies, which can sometimes fix some problems.

If you still have questions, try asking in the official uni-app community or the official Vent-UI community for more help and solutions.