How do I debug custom bindings in MvvmCross

1. Verify Binding Setup**

First, ensure that your custom binding is properly registered in the `Setup.cs` file. This involves overriding the `FillTargetFactories` method to register your custom target binding.

csharp
protected override void FillTargetFactories(IMvxTargetBindingFactoryRegistry registry)
{
    base.FillTargetFactories(registry);
    registry.RegisterPropertyInfoBindingFactory(
        typeof(MyViewMyPropertyTargetBinding),
        typeof(MyView), "MyProperty");
}

2. Check Property and Event Names**

MvvmCross relies on conventions for property and event names. Ensure that your property has a corresponding event with a name that ends in "Changed" (e.g., `MyProperty` should have a `MyPropertyChanged` event). If your control doesn't follow this convention, you'll need to create a custom binding that specifies the event to listen to.

3. Use MvxTrace**

MvvmCross provides a tracing system that can help you diagnose binding issues. You can enable tracing by setting the `MvxTrace` level to `MvxTraceLevel.Diagnostic` or `MvxTraceLevel.Verbose` in your `Setup.cs` or `App.cs` file. This will output detailed logs about binding operations, which can help identify where things are going wrong.

csharp
protected override void InitializeFirstChance()
{
    base.InitializeFirstChance();
    MvxTrace.Initialize();
    MvxTrace.TraceLevel = MvxTraceLevel.Diagnostic;
}

4. Inspect Binding Errors**

Check the output for any binding-related errors. Common issues include missing properties, incorrect event names, or failure to register custom bindings.

5. Verify Property Accessors**

Ensure that the properties you're trying to bind have both a getter and a setter. MvvmCross uses reflection to access these properties, so they must be public and correctly defined.

6. Check for Infinite Loops**

In two-way bindings, ensure that your `SubscribeToEvents` and `SetValueImpl` methods are correctly implemented to avoid infinite loops. Use `MvxConvertingTargetBinding` or its subclasses to help prevent these loops.

7. Test Binding Direction**

If you're using two-way binding, verify that changes in both the view and the view model are correctly propagated. Use breakpoints or logging to monitor when `SetValueImpl` and `HandlePropertyChanged` (or similar event handlers) are called.

8. Platform-Specific Issues**

If you're experiencing issues on specific platforms (e.g., Android or iOS), ensure that any platform-specific requirements are met. For example, on Android, you might need to register custom views in `AndroidViewAssemblies` in `Setup.cs`.

9. Use Debugging Tools**

Use your IDE's debugging tools to step through your code. Set breakpoints in your custom binding classes, especially in `SetValueImpl` and event handling methods, to see if they're being called as expected.

10. Consult Documentation and Community Resources**

If you're still having trouble, refer to MvvmCross documentation and community forums. There are many resources available that cover common pitfalls and solutions for custom bindings.

By following these steps, you should be able to identify and resolve most issues with custom bindings in MvvmCross.