How can I ensure proper cleanup when using strong references in MvvmCross

1. Avoid Strong References to Views**

In MvvmCross, it's crucial to avoid having strong references from ViewModels to Views. This is because Views often hold references to their containing Views, which can lead to memory leaks if not managed properly. Instead, use weak references or event handlers that can be unsubscribed when no longer needed.

2. Use WeakSubscribe for Events**

MvvmCross provides a `WeakSubscribe` method that allows you to subscribe to events without creating strong references. This is particularly useful for events like `PropertyChanged` or custom events in your ViewModels. For example, instead of using a strong reference like `this.ViewModel.Loaded += LoadControls;`, you can use a weak subscription approach:

csharp
this.ViewModel.Loaded += LoadControls; // Strong reference

// Replace with weak subscription
this.ViewModel.Loaded.WeakSubscribe(LoadControls);

However, if you're using `Action` types for events, you might need to implement a custom weak subscription handler or refactor to use `EventHandler` types that are compatible with MvvmCross's weak subscription methods.

3. Implement IDisposable for Cleanup**

If your ViewModels or other objects implement `IDisposable`, ensure that you call `Dispose` when they are no longer needed. This is especially important for objects that hold onto resources like files, network connections, or database handles.

csharp
public class MyViewModel : MvxViewModel, IDisposable
{
    private bool disposed = false;

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!disposed)
        {
            if (disposing)
            {
                // Dispose managed resources here.
            }
            // Dispose unmanaged resources here.
            disposed = true;
        }
    }
}

4. Unsubscribe from Messenger Events**

When using the MvvmCross Messenger for communication between ViewModels, ensure that you unsubscribe from events when the ViewModel is no longer needed. This prevents strong references from keeping the ViewModel alive unnecessarily.

csharp
// Subscribe
_messenger.Subscribe(OnMessageReceived);

// Unsubscribe when no longer needed
_messenger.Unsubscribe(OnMessageReceived);

5. Use Lifecycle Methods for Cleanup**

MvvmCross provides lifecycle methods like `ViewDestroy` that can be used to perform cleanup tasks when a ViewModel is being destroyed. Use these methods to release any resources or unsubscribe from events.

csharp
public override void ViewDestroy(bool viewFinishing = true)
{
    base.ViewDestroy(viewFinishing);
    // Perform cleanup here
}

6. Monitor Memory Usage**

Use profiling tools to monitor memory usage and identify potential leaks. Tools like Visual Studio's Diagnostic Tools or third-party memory profilers can help you understand how memory is being allocated and deallocated in your application.

By following these strategies, you can ensure that strong references in MvvmCross are properly managed, reducing the risk of memory leaks and improving the overall performance of your application.