อยากทราบว่าการกำหนดค่าตัวแปรใน treeview กำหนดเป็น int ไม่ได้หรอค่ะ

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ContentforMobileLearning.DataObjects
{
    public class ContentPage
    {
        private String contentPage = "CONTENT_PAGE";
        public string ContentPages
        {
            get { return contentPage; }
            set { contentPage = value; }
        }

        private String contentSequence = "SEQUENE";
        public string ContentSequence
        {
            get { return contentSequence; }
            set { contentSequence = value; }
        }

        public int sequence = 1 ;
        public int Sequence
        {
            get { return sequence; }
            set { sequence = value; }
        }

        private String contentPageType = "PAGR_TYPE";
        public string ContentPageType
        {
            get { return contentPageType; }
            set { contentPageType = value; }
        }

        private String pageType = "------";
        public string PageType
        {
            get { return pageType; }
            set { pageType = value; }
        }

        private String contentPageDescription = "PAGR_DESCRIPTION";
        public string ContentPageDescription
        {
            get { return contentPageDescription; }
            set { contentPageDescription = value; }
        }

        private String pageDescription = "------";
        public string PageDescription
        {
            get { return pageDescription; }
            set { pageDescription = value; }
        }

        private String contentVideoFileName = "VIDEO_FILE_NAME";
        public string ContentVideoFileName
        {
            get { return contentVideoFileName; }
            set { contentVideoFileName = value; }
        }

        private String videoFileName = "*.mp4";
        public string VideoFileName
        {
            get { return videoFileName; }
            set { videoFileName = value; }
        }

        private String contentImageFileName = "IMAGE_FILE_NAME";
        public string ContentImageFileName
        {
            get { return contentImageFileName; }
            set { contentImageFileName = value; }
        }

        private String imageFileName = "*.jpg";
        public string ImageFileName
        {
            get { return imageFileName; }
            set { imageFileName = value; }
        }

        private String contentSoundeFileName = "SOUND_FILE_NAME";
        public string ContentSoundeFileName
        {
            get { return contentSoundeFileName; }
            set { contentSoundeFileName = value; }
        }

        private String soundeFileName = "*.mp3";
        public string SoundeFileName
        {
            get { return soundeFileName; }
            set { soundeFileName = value; }
        }
    }
}

        public CreateContent()
        {
            InitializeComponent();
            Page();   
            i++;
        }
        int i = 1;

        private void Page()
        {
            ContentPage page = new ContentPage();
            treeView1.Nodes[0].Nodes.Add(page.ContentPages);
            treeView1.Nodes[0].Nodes[i].Nodes.Add(page.ContentSequence);
          [font=Verdana]  treeView1.Nodes[0].Nodes[i].Nodes[0].Nodes.Add(page.Sequence); // คือว่ามัน error  บรรทัดนี้[/font]
            treeView1.Nodes[0].Nodes[i].Nodes.Add(page.ContentPageType);
            treeView1.Nodes[0].Nodes[i].Nodes[1].Nodes.Add(page.PageType);
            treeView1.Nodes[0].Nodes[i].Nodes.Add(page.ContentPageDescription);
            treeView1.Nodes[0].Nodes[i].Nodes[2].Nodes.Add(page.PageDescription);
            treeView1.Nodes[0].Nodes[i].Nodes.Add(page.ContentVideoFileName);
            treeView1.Nodes[0].Nodes[i].Nodes[3].Nodes.Add(page.VideoFileName);
            treeView1.Nodes[0].Nodes[i].Nodes.Add(page.ContentImageFileName);
            treeView1.Nodes[0].Nodes[i].Nodes[4].Nodes.Add(page.ImageFileName);
            treeView1.Nodes[0].Nodes[i].Nodes.Add(page.ContentSoundeFileName);
            treeView1.Nodes[0].Nodes[i].Nodes[5].Nodes.Add(page.SoundeFileName);
        }