The ASP.NET Core framework uses a model metadata provider to extract information from the model. This metadata provider is accessible through the MetadataProperty of Html, and is exposed as an IModelMetadataProvider. By default, it is set to an instance of DefaultModelMetadataProvider, and can be changed through the dependency injection framework.
Its contract defines only two relevant methods:
GetMetadataForType(ModelMetadata): Returns metadata for the model type itselfGetMetadataForProperties(IEnumerable<ModelMetadata>): Metadata for all of the public model properties
To change it, just call one of the registration methods of the dependency injection framework (ConfigureServices):
services.AddSingleton<IModelMetadataProvider, CustomModelMetadataProvider>();
You never normally call these methods, they are called internally by the framework. The ModelMetadata class they return (which may actually be of a derived class, such as DefaultModelMetadata) is what should...