'ModelWithChildren' not found

Question

'ModelWithChildren' not found

BenTam 796

Dear All, I am learning "ObjectListView" by working with the examples (http://objectlistview.sourceforge.net/cs/blog4.html#blog-rearrangingtreelistview). However the following error is shown.

The type or namespace name 'ModelWithChildren' could not be found

Could anybody tell me how to solve it?

TIA

The source code is as follows.

using System;  
using System.Collections;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Data;  
using System.Drawing;  
using System.Linq;  
using System.Text;  
using System.Threading.Tasks;  
using System.Windows.Forms;  
  
namespace TreeListViewDragDrop  
{  
    public partial class Form1 : Form  
    {  
        public Form1()  
        {  
            InitializeComponent();  
            // Configure the first tree  
            treeListView1.CanExpandGetter = delegate (object x) { return true; };  
            treeListView1.ChildrenGetter = delegate (object x) { return ((ModelWithChildren)x).Children; };  
  
            // Configure the second tree  
            treeListView2.CanExpandGetter = delegate (object x) { return true; };  
            treeListView2.ChildrenGetter = delegate (object x) { return ((ModelWithChildren)x).Children; };  
  
            treeListView1.Roots = ModelWithChildren.CreateModels(null, new ArrayList { 0, 1, 2, 3, 4, 5 });  
            treeListView2.Roots = ModelWithChildren.CreateModels(null, new ArrayList { "A", "B ", "C", "D", "E" });  
        }  
    }  
}

BenTam 796 Reputation points

2021-07-01T14:07:08.807+00:00

Hi Karen. Do you mean adding "using Form1"?
Karen Payne MVP 30,121 Reputation points

2021-07-01T14:24:38.92+00:00
No, a using statement for the library which contains ObjectListView. Or you can precede ModelWithChildren with the namespace to where ObjectListView resides.

Since I have not downloaded the library here is an example. I have a class called Customer in a project named DataLibrary then in my form project I reference DataLibrary. To access Customer class I use

using DataLibrary.Classes;

Then to create a Customer

Customer customer = new Customer();

Option 2
No using statement

DataLibrary.Customer customer = new Customer();

Or if Customer existed in a sub namespace DataLibrary.Classes I would write DataLibrary.Classes.Customer customer - new Customer();
BenTam 796 Reputation points

2021-07-02T03:43:11.737+00:00

Hi Karen. I have searched the "namespace" for "using" for several days without success. Could you tell me the name of the "namespace" or how to search?
Karen Payne MVP 30,121 Reputation points

2021-07-02T17:32:43.253+00:00

Your namespace in your project is TreeListViewDragDrop, all the using statements above e.g. using System, System is a namespace. What you need to do is find the namespace that ModelWithChildren is under and add a using statement like using System;

Also, in regards to the red squiggles, you might try hovering over the squiggles and see if there is a recommendation. I don't know as I use a extension that automatically adds missing references/using statement.
BenTam 796 Reputation points

2021-07-03T14:22:12.873+00:00

Hi Karen. Is it possible telling me how to search?
Daniel Zhang-MSFT 9,476 Reputation points

2021-07-05T08:13:43.747+00:00
Hi @BenTam ,
In the link you provided, it is mentioned in the Dumb models section of the article that all of ObjectListView’s controls revolve around model objects. So, to make a working TreeListView, we need a model for it to display:

public class ModelWithChildren { ..... }

So whether the ModelWithChildren class is added to your project?
And the final source code link is provided at the end of the article.
Best Regards,
Daniel Zhang
BenTam 796 Reputation points

2021-07-05T14:35:09.857+00:00

Hi Daniel. Thanks for your reply,

The last line of the article is "You can download final source code from here." However when I click on the link it shows
"The "/objectlistview/Tree..eListViewDragDrop.7z" file could not be found or is not available. Please select another file."

May I know how to get the source.
Daniel Zhang-MSFT 9,476 Reputation points

2021-07-06T02:31:19.15+00:00

Hi @BenTam ,
Since the source code is not available, I suggest you click the discussion button on the right side of the article and ask for help on the discussion page.

Best Regards,
Daniel Zhang
BenTam 796 Reputation points

2021-07-06T05:47:09.943+00:00

Thanks for your reply. I'll posting on the site.

BenTam 796 Reputation points

2021-07-01T14:07:08.807+00:00

Hi Karen. Do you mean adding "using Form1"?
Karen Payne MVP 30,121 Reputation points

2021-07-01T14:24:38.92+00:00

No, a using statement for the library which contains ObjectListView. Or you can precede ModelWithChildren with the namespace to where ObjectListView resides.

Since I have not downloaded the library here is an example. I have a class called Customer in a project named DataLibrary then in my form project I reference DataLibrary. To access Customer class I use

using DataLibrary.Classes;

Then to create a Customer

Customer customer = new Customer();

Option 2
No using statement

DataLibrary.Customer customer = new Customer();

Or if Customer existed in a sub namespace DataLibrary.Classes I would write DataLibrary.Classes.Customer customer - new Customer();
BenTam 796 Reputation points

2021-07-02T03:43:11.737+00:00

Hi Karen. I have searched the "namespace" for "using" for several days without success. Could you tell me the name of the "namespace" or how to search?
Karen Payne MVP 30,121 Reputation points

2021-07-02T17:32:43.253+00:00

Your namespace in your project is TreeListViewDragDrop, all the using statements above e.g. using System, System is a namespace. What you need to do is find the namespace that ModelWithChildren is under and add a using statement like using System;

Also, in regards to the red squiggles, you might try hovering over the squiggles and see if there is a recommendation. I don't know as I use a extension that automatically adds missing references/using statement.
BenTam 796 Reputation points

2021-07-03T14:22:12.873+00:00

Hi Karen. Is it possible telling me how to search?
Daniel Zhang-MSFT 9,476 Reputation points

2021-07-05T08:13:43.747+00:00

Hi @BenTam ,
In the link you provided, it is mentioned in the Dumb models section of the article that all of ObjectListView’s controls revolve around model objects. So, to make a working TreeListView, we need a model for it to display:

public class ModelWithChildren { ..... }

So whether the ModelWithChildren class is added to your project?
And the final source code link is provided at the end of the article.
Best Regards,
Daniel Zhang
BenTam 796 Reputation points

2021-07-05T14:35:09.857+00:00

Hi Daniel. Thanks for your reply,

The last line of the article is "You can download final source code from here." However when I click on the link it shows
"The "/objectlistview/Tree..eListViewDragDrop.7z" file could not be found or is not available. Please select another file."

May I know how to get the source.
Daniel Zhang-MSFT 9,476 Reputation points

2021-07-06T02:31:19.15+00:00

Hi @BenTam ,
Since the source code is not available, I suggest you click the discussion button on the right side of the article and ask for help on the discussion page.

Best Regards,
Daniel Zhang
BenTam 796 Reputation points

2021-07-06T05:47:09.943+00:00

Thanks for your reply. I'll posting on the site.

Answer 1

Karen Payne MVP 30,121

If this is for ObjectListView then you need to add a reference to your project followed by adding a using statement to form1.

BenTam 796 Reputation points

2021-07-05T14:42:01.6+00:00

Hi Karen. Thanks for your reply. Very often when I download an example, I need to add some "using XXXXX". My question is how to search XXXXX?

'ModelWithChildren' not found

1 answer

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