Hi Chris,

Approach to get value of control straight after it was dynamically created (within same server event) looked unusual to me, so, I tested slider and standard textbox for that. None of them worked, and TextBox was not able to return value even from previous session (I guess because textbox does not use ViewState to store Text property).

You should separate in time creation of dynamic control and getting its value from last session: use different threads/events/etc. I would suggest to move creation of sliders in Page.OnInit. However, if you for some reason can not use OnInit, then you may create sliders in Page.OnLoad, but get value from last session within Page.OnLoadComplete or later. Below example has submit button and 2 text boxes to show outputs of results.

 private TextBox _textbox;
 private WebSlider _slider;
 protected void Page_Load(object sender, EventArgs e)
 {
  this._textbox = new TextBox();
  this._textbox.ID = "TB1";
  this.Form.Controls.Add(this._textbox);
  this._slider = new WebSlider();
  this._slider.ID = "MySliderUniqueID";
  this.Form.Controls.Add(this._slider);
  this.TextBox1.Text = "Slider:" + this._slider.Value + " text=" + this._textbox.Text;
 }
 protected void Page_LoadComplete(object sender, EventArgs e)
 {
  this.TextBox2.Text = "Slider:" + this._slider.Value + " text=" + this._textbox.Text;
 }