请问Asp.Net MVC中问号后跟一个点是什么意思?比如如下代码:
public object BindModel(ControllerContext controllerContext, System.Web.Mvc.ModelBindingContext bindingContext)
{
var rawValue = bindingContext.ValueProvider.GetValue(bindingContext.ModelName)?.RawValue;
...........
...........
}
else
{
return null;
}
}