C# WinApp อยากเพิ่ม EventHandler DataGridView_CellClick ใน class DataGridViewTextBoxCell ที่สร้างขึ้นมาใหม่ต้อง EventHandler ยังไง ตรงไหน ครับ

public class DataGridViewFilePathColumn : DataGridViewColumn
{

    public enum PathType { directory, file };
    public PathType pathtype = PathType.file;

    public DataGridViewFilePathColumn()
        : base(new DataGridViewFilePathCell())
    {

    }
    public override DataGridViewCell CellTemplate
    {
        get
        {
            return base.CellTemplate;
        }
        set
        {
            if (null != value &&
                !value.GetType().IsAssignableFrom(typeof(DataGridViewFilePathCell)))
            {
                throw new InvalidCastException("must be a DataGridViewFilePathCell");
            }
            base.CellTemplate = value;
        }
    }
}
public class DataGridViewFilePathCell : DataGridViewTextBoxCell
{
    Button browseButton;

    private void DataGridView_CellClick(object sender, DataGridViewCellEventArgs e)
    {
        if (base.Value.ToString().Length > 0)
        {
            System.Diagnostics.Process.Start(base.Value.ToString());
        }
    }
    void browseButton_Click(object sender, EventArgs e)
    {
        DataGridViewFilePathColumn filePathColumn = (DataGridViewFilePathColumn)this.DataGridView.Columns[ColumnIndex];
        if (filePathColumn.pathtype == DataGridViewFilePathColumn.PathType.file)
        {
            OpenFileDialog fdg = new OpenFileDialog();
            fdg.ShowDialog();
            base.Value = (fdg.FileName.Length > 0) ? fdg.FileName : base.Value;
        }
        else
        {
            FolderBrowserDialog fdg = new FolderBrowserDialog();
            fdg.ShowDialog();
            base.Value = (fdg.SelectedPath.Length > 0) ? fdg.SelectedPath : base.Value;
        }
    }
    public DataGridViewFilePathCell()
        : base()
    {
        browseButton = new Button();
        browseButton.Text = "…";
        browseButton.Click += new EventHandler(browseButton_Click); //yes, really two event handlers!
      //  base.DataGridView.CellClick +=DataGridView_CellClick;
    }
}