Troubleshooting issues with the `GetPluginAssemblies` method in MvvmCross 6.4.2 involves several steps to identify and resolve potential problems. Here's a detailed guide to help you through the process:
1. Understand the Method's Purpose**
The `GetPluginAssemblies` method is responsible for retrieving assemblies that contain MvvmCross plugins. These plugins are essential for extending the functionality of your application.2. Check Assembly References**
Ensure that all assemblies referenced by your project are correctly loaded and accessible. This includes checking for any missing or mismatched versions of MvvmCross or its plugins.3. Verify Plugin Installation**
Confirm that the plugins you are trying to load are correctly installed via NuGet. Ensure that both the shared core project and your application projects include the necessary NuGet packages.4. Override the LoadPlugins Method**
In your platform-specific `Setup.cs` file (e.g., `MvxAndroidSetup.cs` for Android), override the `LoadPlugins` method to manually load plugins if necessary. This can help identify issues with automatic plugin loading.csharp
public override void LoadPlugins(IMvxPluginManager pluginManager)
{
// Example code to load plugins manually
Type pluginAttribute = typeof(MvxPluginAttribute);
IEnumerable pluginAssemblies = GetPluginAssemblies();
foreach (Assembly assembly in pluginAssemblies)
{
IEnumerable types = assembly.ExceptionSafeGetTypes();
foreach (Type type in types)
{
if (TypeContainsPluginAttribute(type))
{
pluginManager.EnsurePluginLoaded(type);
}
}
}
}
// Helper method to check for plugin attribute
private bool TypeContainsPluginAttribute(Type type)
{
object[] customAttributes = type.GetCustomAttributes(typeof(MvxPluginAttribute), inherit: false);
return customAttributes != null && customAttributes.Length > 0;
}
5. Check for NullReferenceExceptions**
If you encounter a `NullReferenceException`, it might be due to `GetPluginAssemblies` returning no assemblies or an issue within the `LoadPlugins` method. Use debugging tools to inspect the `pluginAssemblies` collection and ensure it is populated correctly.6. Inspect Assembly Loading**
Verify that the assemblies containing plugins are loaded into the application domain. You can do this by checking `AppDomain.CurrentDomain.GetAssemblies()`.7. Version Compatibility**
Ensure that all MvvmCross libraries and plugins are on the same version to avoid compatibility issues. This is crucial as different versions might have different assembly names or loading mechanisms.8. Debugging Techniques**
Use try-catch blocks to catch exceptions and inspect the stack trace for more detailed error information. This can help pinpoint where the issue occurs.csharp
try
{
// Code that loads plugins
}
catch (Exception ex)
{
// Inspect ex.StackTrace for more information
}
9. Consult Documentation and Guides**
Refer to the official MvvmCross documentation and guides for upgrading and using plugins. Sometimes, specific versions have unique requirements or known issues that are documented.10. Community Support**
If none of the above steps resolve your issue, consider seeking help from the MvvmCross community forums or GitHub issues. Providing detailed error messages and code snippets can help others assist you more effectively.Citations:
[1] https://stackoverflow.com/questions/73128508/how-to-load-plugins-when-updating-to-mvvmcross-6-4-2-from-5-6-2
[2] https://stackoverflow.com/q/33774785
[3] https://stackoverflow.com/questions/32067695/mvvmcross-missing-viewmodels-parameters-with-link-all-assemblies-enabled?rq=1
[4] https://github.com/MvvmCross/MvvmCross/blob/develop/CHANGELOG.md
[5] https://www.mvvmcross.com/documentation/fundamentals/inversion-of-control-ioc
[6] https://www.mvvmcross.com/documentation/advanced/customizing-using-App-and-Setup
[7] https://www.nuget.org/packages/MvvmCross.Plugin.All/
[8] https://github.com/MvvmCross/MvvmCross/issues/3774