C# WinApp สงสัยเกี่ยวกับการตั้งค่า System.ComponentModel.DefaultValue(true) ครับ

public partial class UserControl1 : UserControl
    {
            private System.Windows.Forms.TextBox textBox1;
        public UserControl1()
        {

            InitializeComponent();
            this.textBox1.Location = new System.Drawing.Point(32, 45);
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(223, 20);
            this.textBox1.TabIndex = 0;
        }
        private Boolean _ReadOnly;
        [System.ComponentModel.DefaultValue(true)]
        [System.ComponentModel.Browsable(true)]
        [System.ComponentModel.Category("Behavior")]
        public Boolean ReadOnly
        {
            get { return _ReadOnly; }
            set { _ReadOnly = value; }
        } 

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