C# reflection use variable as object.[var]

Question

I'm trying to generate a table in a razor view using reflection to pull the properties from the model.

Here is what I've tried:

@if (@Model.Count() > 0)
{
    System.Reflection.PropertyInfo[] properties = Model.First().GetType().GetProperties();
    <table>
        <thead>
            <tr>

            @foreach (var property in properties)
            {
                if (char.IsLower(property.Name.ToCharArray()[0])) //ignore foreign keys
                {
                    continue;
                }
                <th>@property.Name</th>
            }
            </tr>
        </thead>
        <tbody>
            @foreach (PCNWeb.Models.Switch item in Model)
            {
                /*System.Reflection.PropertyInfo[]*/ properties = item.GetType().GetProperties();
                <tr>
                @foreach (var property in properties)
                {                    
                    <td>
                        @Html.DisplayFor(modelItem => item.[property.Name])
                    </td>
                }
                </tr>

            }
        </tbody>
    </table>
}

Let me point out the part of the code that I'm not sure what to do with:

<td>
    @Html.DisplayFor(modelItem => item.[property.Name])
</td>

The property.Name contains the name of the property of item that I want to access. If I were to hand write the innermost td one example would be:

<td>
    @Html.DisplayFor(modelItem => item.Switch_Location)
</td>

where "Switch_Location" is the value of property.Name

So basically I need to access the value of a property of item based on the name of the property stored in a variable.

EDIT adding model:

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace PCNWeb.Models
{
    public partial class Switch
    {
        public Switch()
        {
            this.Ports = new List<Port>();
            this.Switch_Location = new Switch_Location();
            this.Switch_Model = new Switch_Model();
            this.UPS = new UPS();
        }
        [Key]
        public int switchRecId { get; set; }
        [Required]
        public int locationRecId { get; set; }
        [Required]
        public int modelRecId { get; set; }
        //public int gatewayRecId { get; set; }
        [Required]
        public int upsRecId { get; set; }
        [Required]
        public int Number { get; set; }
        [Required]
        [StringLength(64)]
        public string Name { get; set; }
        [StringLength(80)]
        public string Description { get; set; }

        [StringLength(32)]
        public string Cabinet { get; set; }

        [StringLength(40)]
        public string Power_Feed { get; set; }
        [Required]
        public Nullable<int> ipOctet1 { get; set; }
        [Required]
        public Nullable<int> ipOctet2 { get; set; }
        [Required]
        public Nullable<int> ipOctet3 { get; set; }
        [Required]
        public Nullable<int> ipOctet4 { get; set; }

        public virtual ICollection<Port> Ports { get; set; }
        public virtual Switch_Location Switch_Location { get; set; }
        public virtual Switch_Model Switch_Model { get; set; }
        public virtual UPS UPS { get; set; }
    }
}

@DanielA.White What dose using a ViewModel get me? I really like the idea of having the least amount of handwritten code thus this approach. — TechplexEngineer
– TechplexEngineer, Commented Jul 17, 2013 at 14:25
Reflection is the most inefficient way to write code. Use it little and not very often! — Liam
– Liam, Commented Jul 17, 2013 at 14:29
I must not understand "separation of concerns" I feel like this method completely decouples the view from the data. And loose coupling is good, so If I change my data I don't have to change my views. — TechplexEngineer
– TechplexEngineer, Commented Jul 17, 2013 at 14:39

Ben Voigt · Accepted Answer · 2013-07-17 14:26:48Z

4

So basically I need to access the value of a property of item based on the name of the property stored in a variable.

No, you need to access the value of a property based on a PropertyInfo object describing it. That's far far easier.

property.GetValue(item)

answered Jul 17, 2013 at 14:26

Ben Voigt

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7 Comments

TechplexEngineer Over a year ago

using property.GetValue(item) yields this: PCNWeb.Models.Switch_Location in my datatable. Is there a way to get the actual data?

Lasse V. Karlsen Over a year ago

That should give the actual data.

Ben Voigt Over a year ago

@TechplexEngineer: I think your Html.DisplayFor is calling ToString() on the object. If you want to change the string, write a better Switch_Location.ToString()

TechplexEngineer Over a year ago

Ohhhh So I've added my model of a switch above, since a switch has "sub"objects I'll need a way to get their value.

Simon Belanger Over a year ago

@BenVoigt DisplayFor is more complex than that. It also checks for attributes on the member as hint on how to display the property.

|

Botonomous · Accepted Answer · 2013-07-17 14:31:32Z

0

If you dont really need the DisplayFor method, you can do it like this in your loop:

<tbody>
            @foreach (PCNWeb.Models.Switch item in Model)
            {
                /*System.Reflection.PropertyInfo[]*/ properties = item.GetType().GetProperties();
                <tr>
                @foreach (var property in properties)
                {                    
                    <td>
                        @property.GetValue(item,null)
                    </td>
                }
                </tr>

            }
        </tbody>

edited Jul 17, 2013 at 14:31

answered Jul 17, 2013 at 14:25

Botonomous

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1 Comment

TechplexEngineer Over a year ago

In the table, this is just printing the propertyName, I was trying to use the DisplayFor to get the propertyValue. How can I access the underlying data?

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