C# ช่วยดูโค้ดให้หน่อยครับ ถ้าแบบนี้ต้องแก้โค้ดยังไงครับ

[ToolboxBitmap(typeof(TextBox))]
    public partial class TextboxDialog : TextBox
    {
        
        private bool bLinkClicked;
        public TextboxDialog()
        {
            InitializeComponent();
            _lnk.Text = this.Text;

        }
        private System.Windows.Forms.LinkLabel _lnk;
        private System.Windows.Forms.Button _btn;
        // private System.Windows.Forms.TextBox _txt;

        #region Component Designer generated code

        /// <summary> 
        /// Required method for Designer support - do not modify 
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this._lnk = new System.Windows.Forms.LinkLabel();
            this._btn = new System.Windows.Forms.Button();
            Font fnt = new System.Drawing.Font("Microsoft Sans Serif", 10.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(222)));
            // 
            // _lnk
            // 
            this._lnk.AutoSize = true;
            this._lnk.BackColor = System.Drawing.SystemColors.ControlLight;
            this._lnk.Font = fnt;
            this._lnk.Location = new System.Drawing.Point(-1, 1);
            this._lnk.Name = "_lnk";
            this._lnk.Size = new System.Drawing.Size(79, 16);
            this._lnk.TabIndex = 1;
            this._lnk.TabStop = true;
            this._lnk.Text = "linkLabel1";
            this._lnk.LinkClicked += new System.Windows.Forms.LinkLabelLinkClickedEventHandler(this._lnk_LinkClicked);
            // 
            // _btn
            // 
            this._btn.Dock = System.Windows.Forms.DockStyle.Right;
            this._btn.Image = DATA_ASSET.Properties.Resources.finds;// global::TORServices.FormsTor.Properties.Resources.search32x32;
            this._btn.Font = fnt;
            this._btn.FlatStyle = FlatStyle.Flat;
            this._btn.Location = new System.Drawing.Point(478, 0);
            this._btn.Margin = new System.Windows.Forms.Padding(4);
            this._btn.Cursor = Cursors.Hand;
            this._btn.Name = "_btn";
           // this._btn.Text = "...";
            this._btn.Size = new System.Drawing.Size(20, this.Height);
            this._btn.TabIndex = 2;
            this._btn.UseVisualStyleBackColor = true;
            this._btn.Click += new System.EventHandler(this._btn_Click);
            // 
            // TextboxDialog
            // 

            this.Controls.Add(this._lnk);
            this.Controls.Add(this._btn);
            this.Font = fnt;
            this.Margin = new System.Windows.Forms.Padding(4);
            this.Name = "TextboxDialog";
            this.Size = new System.Drawing.Size(300, 24);
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        #region _Property


        private string _Path;
        [System.ComponentModel.Browsable(true)]
        [System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Always)]
        [System.ComponentModel.DefaultValue(@"C:")]
        [System.ComponentModel.Category("TOR Setting")]
        [System.ComponentModel.Description("Open Dialog is dispalyed and on success the contents of the Cell is replaced with the new  path.")]
        public string Directory
        {
            get
            {
                return _Path;
            }
            set
            {
                _Path = value;
            }
        }

        #endregion
        public string FullPath
        {
        get{return _Path + "\\" + this.Text;}
        }
         

        private void _btn_Click(object sender, EventArgs e)
        {
            try
            {
                string directory = (string.IsNullOrEmpty(Directory)) ? Application.StartupPath : Directory.Replace("AppPath", Application.StartupPath);
                if (!System.IO.Directory.Exists(directory)) System.IO.Directory.CreateDirectory(directory);

                
                    OpenFileDialog dialog = new OpenFileDialog();
                    if (dialog.ShowDialog() == DialogResult.OK)
                    {

                        SaveFileDialog dialog1 = new SaveFileDialog();
                        dialog1.InitialDirectory = (!string.IsNullOrEmpty(directory)) ? directory : "";
                        dialog1.FileName = System.IO.Path.GetFileName(dialog.FileName);

                        if (dialog1.ShowDialog() == DialogResult.OK)
                        {
                            // SetPath(dialog.FileName);
                            this.Text =  System.IO.Path.GetFileName(dialog1.FileName);
                            if (dialog.FileName != dialog1.FileName)
                                System.IO.File.Copy(dialog.FileName, dialog1.FileName, true);
                        }

                    }

            }
            catch (Exception)
            {
            }
        }

        #region Focus overrides
        protected override void OnFontChanged(EventArgs e)
        {
            _btn.Font = Font;
            _lnk.Font = Font;

        }
        protected override void OnLostFocus(EventArgs e)
        {
            base.OnLostFocus(e); this.SwitchToEditMode(false);

        }
        protected override void OnGotFocus(EventArgs e)
        {
            base.OnGotFocus(e); this.SwitchToEditMode(true);
        }
        protected override void OnTextChanged(EventArgs e)
        {
            base.OnTextChanged(e);
            _lnk.Text = this.Text;
            _lnk.Links.Clear();
            _lnk.Links.Add(0, _lnk.Text.Length, FullPath);
        }

        private void _txt_TextChanged(object sender, EventArgs e)
        {

        }

        private void _txt_BackColorChanged(object sender, EventArgs e)
        {
            _lnk.BackColor = this.BackColor;
        }
        public event EventHandler ButtonClick
        {
            add
            {
                _btn.Click += value;
            }
            remove
            {
                _btn.Click -= value;
            }
        }

        public event EventHandler ButtonDoubleClick
        {
            add
            {
                _btn.DoubleClick += value;
            }
            remove
            {
                _btn.DoubleClick -= value;
            }
        }

        protected void SwitchToEditMode(bool _bEditMode)
        {
            _lnk.Visible = !_bEditMode;

        }


        #endregion

        #region Link Activation
        private void _lnk_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
          /*  try
            {*/
                if (_lnk.Links.Count > 0)
                {
                    if (System.IO.File.Exists(FullPath))
                    {
                        System.Diagnostics.Process.Start(FullPath);
                    }
                    else
                    {
                        MessageBox.Show("File Not Found"); return;
                    }
                }

           /* }
            catch (Exception ex)
            {
                throw new ArgumentException("Link error!", ex);
            }*/

        }


        #endregion

        #region Focus Handling

        private void _lnk_GotFocus(object sender, EventArgs e)
        {
            if (!bLinkClicked)
            {
                this.Focus();
                bLinkClicked = false;
            }
        }

        private void _lnk_MouseDown(object sender, MouseEventArgs e)
        {
            bLinkClicked = true;
        }

        #endregion




    }