how to post data from custom server control to page

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ASP.NET

I have defined class customtextbox inherits webcontol and implement IPostBackDataHandler, it contain all properties and render method.
I have wired the OnTextChanged event and wired it to my custom control like this:

Page.Page.RegisterRequiresPostBack(CustomTextBox1);

Is this a correct way to call?
My doubt is that the parameter inside the method represent correct way or should I change to anything else.

I am not getting my posted back data in text box to my custom page.

My aspx page:

protected override void OnInit(EventArgs e)
   {
       base.OnInit(e);
       if (Page != null)
       {
           //Page.RegisterRequiresPostBack(CustomTextBox1);
           Page.RegisterRequiresRaiseEvent(CustomImageButton1);
       }
   }
   protected void Page_Load(object sender, EventArgs e)
   {

   }

My custom sever control page:

public class CustomTextBox : WebControl,IPostBackDataHandler
    {
     
     public string Text
        {
            get
            {
                String s = (String)ViewState["Text"];
                return s;
            }

            set
            {
                ViewState["Text"] = value;
            }
        }

        public CustomTextBox() : base(HtmlTextWriterTag.Input)
        {
            
            Text = " ";
        }

        public event EventHandler TextChanged;
        protected override void RenderContents(HtmlTextWriter output)
        {
            output.AddAttribute(HtmlTextWriterAttribute.Type, "text");
            output.AddAttribute(HtmlTextWriterAttribute.Value, Text);
            output.AddAttribute("name", this.UniqueID);
            base.AddAttributesToRender(output);
            
        }
        public bool LoadPostData(string postDataKey, NameValueCollection postData)
        {
            // Get the posted value and the most recent view state value.
            string postedValue = postData[postDataKey];
            string s = postData[0];
            string viewstateValue = Text;
            // If the value changed, then reset the value of the text property
            // and return true so the RaisePostDataChangedEvent will be fired.
            if (viewstateValue != postedValue)
            {
                Text = postedValue;
                return true;
            }
            else
            {
                return false;
            }
        }
        
        public void RaisePostDataChangedEvent() 
        {
            // Call the method to raise the change event.
            OnTextChanged(new EventArgs());
        }
        protected virtual void OnTextChanged(EventArgs e)
        {
            // Check for at least one listener, and then raise the event.
            if (TextChanged != null)
                TextChanged(this, e);
           
        }

Appreciation in advance