how to loop a service object in the view in MVC-CodePudding

I have the following code:

@foreach (var item in @ViewBag.list)
     {
      <span>@item.Id </span> 
     }

The ViewBag gets the data from a service that contains a class that gets the data from a database, but I'm getting a null exception error since the ViewBag is null because a user has to first enter a date to be able to get the list of ids.

public async Task<ActionResult> plan_post(DateTime dateselected)
    {
        
            DateTime date = dateselected;
            var plan = await _ps.PlanbyDate(date, date);
            ViewBag.list = plan;
            
           
            return View();
      
       
    }

I'm a student doing an internship can you help me with this?

this is the error:

System.NullReferenceException: 'Object reference not set to an instance of an object.'

CodePudding user response：

Fo fixed your problem you must debugging your plan object may be null !!!

But you must check if viewbag null not render foreach

if(ViewBag.list != null)
{
//write for each in here
}

You have more options for pass Model to view.

I recommend you use pass with View function

retune View(plan)

But must declaration datatyoe model in top page view

@model YourDataType