ValidateModelAttribute.cs

public class ValidateModelAttribute : ActionFilterAttribute 
{ 
    public override async Task OnActionExecutionAsync(ActionExecutingContext context, Action 
    { 
        var result = new ViewResult(); 
        if (!context.ModelState.IsValid) 
        { 
            // Usually POST action looks like: IActionResult Save(MyMode model) 
            // if validation failed we need to forward that model back to view 
            // Model is in ActionArgument[0] in this case, but you may tweak 
            // this to your specific needs 
            if (context.ActionArguments.Count > 0) 
            { 
                SetViewData(context, result); 
            } 
            // This is same as  
            // return View(mnodel); 
            context.Result = result; 
        } 
        else 
        { 
            try 
            { 
                // This was all happening BEFORE actione executed. 
                // Lets exec the action now and catch possible exceptions! 
                await next.Invoke(); 
            } 
            // You can catch here app specific exception! 
            // catch(MySpecialException e) 
            catch (Exception e) 
            { 
                // Uh, something went wrong:( 
                 
                // Pull logger for IOC container. 
                // Note: I don't really like this approach, it would be much nicer to inject 
                // interfaces into ctor, but then we wouldn't be able to use this filter like: 
                // [ValidateModel] <- ctor requires interface, doesn't compile 
                // but like this: 
                // [ServiceFilter(typeof(ValidateModelAttribute))] 
                // so pick whatever approach you like! 
                var loggerFactory = context.HttpContext.RequestServices.GetService<ILoggerFactory>(); 
                
                var message = e.Unwrap().Message; // Dig for inner exception message 
                
                var descriptor = context.ActionDescriptor as ControllerActionDescriptor; 
                var logger = loggerFactory.CreateLogger(descriptor.ControllerName); 
                
                logger.LogError($"Error while executing {descriptor.ControllerName}/{descriptor.ActionName}: {message}");

                // Sets view model, and adds error to ModelState list 
                if (context.ActionArguments.Count > 0) 
                { 
                    SetViewData(context, result); 
                    result.ViewData.ModelState.AddModelError("", message); 
                } 
                // Again, return View(model); 
                context.Result = result; 
            } 
             
        } 
    } 
    
    /// <summary> 
    /// Sets view model from action executing context 
    /// </summary> 
    private static void SetViewData(ActionExecutingContext context, ViewResult result) 
    { 
        result.ViewData = new ViewDataDictionary( 
            context.HttpContext.RequestServices.GetService<IModelMetadataProvider>(), 
            context.ModelState); 
        result.ViewData.Model = context.ActionArguments.First().Value; 
    } 
}