c# - Accessing and checking values of dynamic controls ASP.NET -

i have scenario. following code:

home.aspx.cs

protected void button1_click(object sender, eventargs e) {     try         {             if (!string.isnullorempty(txtbox_query.text.trim()))                 {                     if (istrue)                         {                             // statements                         }                         else                         {                             list<requestandresponse.parameter> parameters = request.getparameter(txtbox_query.text.trim(), sourcepath, parametervalue);                             session["data"] = parameters;                             response.redirect("result.aspx",false);                         }                      }      }         catch (exception error)         {                 response.write(error.message);         } } 

result.aspx.cs

protected void page_load(object sender, eventargs e) {     parameters = (list<requestandresponse.parameter>)session["data"];         contentplaceholder content = (contentplaceholder)this.form.findcontrol("maincontent");         (int j = 1; j <= _arrviewstate; j++)         {             string _id = j.tostring();                 textbox txtfname = new textbox();                 txtfname.id = "textbox_" + _id + "_";                 txtfname.width = 160;                 txtfname.text = parameters[(j - 1)].value.toupper();                 txtfname.attributes.add("style", "color:#015d84;font-weight:bold;font-size:12px;padding:10px;");                 txtfname.enableviewstate = true;                 content.controls.add(txtfname);                 content.controls.add(new literalcontrol("<br/>"));         }         button btnsubmit = new button();         btnsubmit.id = "btnsubmit";         btnsubmit.text = "submit";         btnsubmit.click += new system.eventhandler(btnsubmit_click);         btnsubmit.enabled = false;         content.controls.add(btnsubmit); }  protected void btnsubmit_click(object sender, eventargs e) {     // how find dynamically created textbox } 

now how find dynamically created controls know basic like:

form.findcontrol("textbox id"); 

but here dont know textbox id , dont know how many textbox totally depends on user input i.e. 2 n textboxes want on bttn_click fetch text textboxes how achieve this. want check if textbox empty or not on bttn_click

enumerate controls follows

protected void btnsubmit_click(object sender, eventargs e) {     contentplaceholder content = (contentplaceholder)this.form.findcontrol("maincontent");     foreach (control c in content.controls)     {         if (c textbox)         {             textbox txt = (textbox)c;             // something, e.g. response.write(txt.text);         }      } }