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Control Cache Duplicating textboxes

I'm trying to create textboxes based on the amount selected from the drop down list; however say I select 2 it shows the 2 textboxes, and I go and select 3 then the 3 textboxes is added to the other 2 textboxes making it 5 textboxes. I tried null the control cache but one extra textbox seem to always be adding.
protected List<Control> ControlCache
{
get { return (List<Control>)(Session["cachedControlsForPageX"] = (Session["cachedControlsForPageX"] as List<Control>) ?? new List<Control>()); }
set { Session["cachedControlsForPageX"] = value; }
}
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
foreach (var control in ControlCache)
{
ContentPlaceHolder1.Controls.Add(control);
ContentPlaceHolder1.Controls.Add(new LiteralControl(" "));
}
}
else
ControlCache = null;
}
protected void ddlCount_SelectedIndexChanged(object sender, EventArgs e)
{
int count = Convert.ToInt32(ddlCount.SelectedItem.Value);
for (int i = 0; i < count; i++)
{
ControlCache = null;
TextBox tx = new TextBox();
tx.MaxLength = 10;
ContentPlaceHolder1.Controls.Add(tx);
ContentPlaceHolder1.Controls.Add(new LiteralControl(" "));
ControlCache.Add(tx);
}
}

Control Cache adding textboxes on auto post back

When the user selects the amount of textboxes require then that number of textboxes are populated. However, say the user selects 1 then goes back to change the amount to 2; then the amount of textboxes shown is 3. How do I stop it from adding when the page reloads.
protected List<Control> ControlCache
{
get { return (List<Control>)(Session["cachedControlsForPageX"] = (Session["cachedControlsForPageX"] as List<Control>) ?? new List<Control>()); }
set { Session["cachedControlsForPageX"] = value; }
}
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
foreach (var control in ControlCache)
{
ContentPlaceHolder1.Controls.Add(control);
ContentPlaceHolder1.Controls.Add(new LiteralControl(" "));
}
}
else
ControlCache = null;
}
protected void ddlCount_SelectedIndexChanged(object sender, EventArgs e)
{
int count = Convert.ToInt32(ddlCount.SelectedItem.Value);
for (int i = 0; i < count; i++)
{
TextBox tx = new TextBox();
tx.MaxLength = 10;
ContentPlaceHolder1.Controls.Add(tx);
ContentPlaceHolder1.Controls.Add(new LiteralControl(" "));
ControlCache.Add(tx);
}
}

get values from dynamically added textboxes asp.net c#

as suggested in the title i have in which i can insert how many textboxes i want to add to a placeholder. i can add the textboxes just fine the problem is i cant get the values inserted on those dynamically added textboxes. here's my code
the purpose of this piece of code is to whenever the textbox in which i can introduce the number of textboxes i want. it creates and adds them to the placeholder in my page.
public void txtExtra_TextChanged(object sender, EventArgs e)
{
for (a = 1; a <= int.Parse(txtExtra.Text); a++)
{
TextBox txt = new TextBox();
txt.ID = "txtquestion" + a;
pholder.Controls.Add(txt);
}
}
this is the code of the button that will submit and response.write the values inserted in all those textboxes.
protected void btnConfirm_Click(object sender, EventArgs e)
{
foreach (Control ctr in pholder.Controls)
{
if (ctr is TextBox)
{
string value = ((TextBox)ctr).Text;
Response.Write(value);
}
}
}
i've been searching online and i've been getting answers that this code is fine and it should work but it doesnt. if you guys see anything wrong or have any suggestion that can solve my problem i'd really appreciate it

You are almost there.
Problem
You need to reload those dynamically created textboxes on post back. Otherwise, they will become null, and you won't be able to find it.
In order to do that, you need to save those dynamically TextBoxes Ids in persistent location such as View State or Session State.
Screen Shot
ASPX
Number of TextBoxes: <asp:TextBox runat="server" ID="CounterTextBox"
OnTextChanged="CounterTextBox_TextChanged" AutoPostBack="True" /><br/>
<asp:PlaceHolder runat="server" ID="TextBoxPlaceHolder" /><br/>
<asp:Button runat="server" ID="ConfirmButton" Text="Confirm"
OnClick="ConfirmButton_Click" /><br/>
Result: <asp:Literal runat="server" ID="ResultLiteral"/>
Code Behind
private List<string> TextBoxIdCollection
{
get
{
var collection = ViewState["TextBoxIdCollection"] as List<string>;
return collection ?? new List<string>();
}
set { ViewState["TextBoxIdCollection"] = value; }
}
protected void Page_Load(object sender, EventArgs e)
{
foreach (string textboxId in TextBoxIdCollection)
{
var textbox = new TextBox {ID = textboxId};
TextBoxPlaceHolder.Controls.Add(textbox);
}
}
protected void CounterTextBox_TextChanged(object sender, EventArgs e)
{
var collection = new List<string>();
int total;
if (Int32.TryParse(CounterTextBox.Text, out total))
{
for (int i = 1; i <= total; i++)
{
var textbox = new TextBox { ID = "QuestionTextBox" + i };
// Collect this textbox id
collection.Add(textbox.ID);
TextBoxPlaceHolder.Controls.Add(textbox);
}
TextBoxIdCollection= collection;
}
}
protected void ConfirmButton_Click(object sender, EventArgs e)
{
foreach (Control ctr in TextBoxPlaceHolder.Controls)
{
if (ctr is TextBox)
{
string value = ((TextBox)ctr).Text;
ResultLiteral.Text += value;
}
}
}

You are actually creating textboxes with property Text set to default = ""; So you need set txt.Text property for example:
public void txtExtra_TextChanged(object sender, EventArgs e)
{
for (int a = 1; a <= int.Parse(txtExtra.Text); a++)
{
TextBox txt = new TextBox();
txt.ID = "txtquestion" + a;
txt.Text = "Some text"; // Set some text here
pholder.Controls.Add(txt);
}
}
EDIT:
After that you can store your values into the list:
private static List<string> values = new List<string>();
protected void btnConfirm_Click(object sender, EventArgs e)
{
foreach (Control ctr in pholder.Controls)
{
if (ctr is TextBox)
{
string value = ((TextBox)ctr).Text;
values.Add(value); // add values here
}
}
}
EDIT:
Here is your values:
EDIT:
For super mega better understanding:
Create one more textbox txtOutput then add button GetDataFromTextBoxesAndPutItBelow and create an event for that button `Click'. Event code:
protected void btnGetData_Click(object sender, EventArgs e)
{
for (int i = 0; i < values.Count; i++)
txtOutput.Text += "Value from txtquestion1: " + values[i] + " ";
}
Screenshot looks:

for (int i = 0; i < dataTable.Rows.Count; i++)
{
int comment_id = Convert.ToInt32(dataTable.Rows[i]["comment_id"]);
string created_by_name = dataTable.Rows[i]["created_by_name"].ToString();
string created_at = dataTable.Rows[i]["created_at"].ToString();
string comment = dataTable.Rows[i]["comment"].ToString();
HtmlGenericControl divComment = new HtmlGenericControl("div"); //This is root object of comment.Other objects like textbox,button,etc added into this object.
//divComment.Attributes.Add("class", "div_post_display");
divComment.Attributes.Add("id", comment_id.ToString());
/* Comment by */
HtmlGenericControl lblCommentBy = new HtmlGenericControl("label");
//lblCommentBy.Attributes.Add("class", "divauthor");
lblCommentBy.InnerText = "" + created_by_name + " (" + created_at + ")";
/* Comment body */
HtmlGenericControl pComment = new HtmlGenericControl("p");
//lblCommentBy.Attributes.Add("class", "divauthor");
pComment.InnerText = comment;
divComment.Controls.Add(lblCommentBy);
divComment.Controls.Add(pComment);
if (Session["user_id"] != null)
{
if (Session["user_level"].ToString() == "1") //Admin can reply for comment
{
/* Reply Form */
TextBox txtReply = new TextBox(); //Create object dynamacaly
txtReply.ID = "txtReply_"+comment_id;
txtReply.Attributes.Add("class", "form-control"); //Add css class
txtReply.Width = 400;
divComment.Controls.Add(txtReply); //Add obj to root object(div)
Button btnReply = new Button(); //Create object dynamacaly
btnReply.Text = "Reply"; //Set button text
btnReply.Attributes.Add("class", "btn btn-sm btn-success"); //Add css class
btnReply.Click += btnReply_Click;
btnReply.CommandArgument = comment_id.ToString();
divComment.Controls.Add(btnReply); //Add obj to root object(div)
HtmlGenericControl br = new HtmlGenericControl("br"); //Create object dynamacaly
divComment.Controls.Add(br); //new line
}
}
pnlShowComments.Controls.Add(divComment);
}

How to get text from dynamically created textboxes in ASP.NET

I created dynamically some textboxes. They are created after click on one button(number of the textboxes depends on the user).
protected void Button1_Click(object sender, EventArgs e)
{
int i = Convert.ToInt32(TextBox2.Text);
Table tbl = new Table();
tbl.Width = Unit.Percentage(80);
TableRow tr;
TableCell tc;
TextBox txt;
CheckBox cbk;
DropDownList ddl;
Label lbl;
Button btn;
for (int j = 1; j <= i; j++)
{
tr = new TableRow();
tc = new TableCell();
tc.Width = Unit.Percentage(25);
lbl = new Label();
lbl.Text = "Pitanje:";
tc.Controls.Add(lbl);
tr.Cells.Add(tc);
tc.Width = Unit.Percentage(25);
txt = new TextBox();
txt.ID = "txt_p_" + j;
tc.Controls.Add(txt);
tr.Cells.Add(tc);
tc.Width = Unit.Percentage(25);
lbl = new Label();
lbl.Text = "Odgovori:";
tc.Controls.Add(lbl);
tr.Cells.Add(tc);
tc.Width = Unit.Percentage(25);
txt = new TextBox();
txt.ID = "txt_o_" + j;
tc.Controls.Add(txt);
tr.Cells.Add(tc);
tbl.Rows.Add(tr);
}
Panel1.Controls.Add(tbl);
}
now I need to get the text that is typed into that textboxes. I tried with something that I found on the internet but can't get it to work.
protected void SpremiPitanja(object sender, EventArgs e)
{
int i = Convert.ToInt32(TextBox2.Text);
for (int j = 1; j <= i; j++)
{
***************************************
}
}
any kind of help is welcome. if you need more information I will give them

A variable declared in a function is only visible in a function. You need to store the TextBoxes in a variable, that exists even when the code in the function has "finished". For more information search for scopes.
Here is a small sample that stores TextBoxes in a List that is visible in your class.
Another option would be to use eventhandlers. It depends on your scenario, which solution would be suited better. If you store the TextBoxes in a List, you can easily perform clean up code (for instance remove EventHandlers if required). You can obviously combine Approach 1 and 2. In that case you would store the created TextBox in a List (or any other collection), but you would still use the sender in the eventhandler to get a reference to the sending TextBox.
public partial class Form1 : Form
{
List<TextBox> textBoxes = new List<TextBox>();
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
//Approach 1: create and add textbox to list
TextBox createdTextbox = new TextBox();
textBoxes.Add(createdTextbox);
}
private void button2_Click(object sender, EventArgs e)
{
//use the textboxes from the list
foreach(TextBox t in textBoxes)
{
//do something with t
}
}
private void button3_Click(object sender, EventArgs e)
{
//Approach 2: use eventhandlers and don't store textbox in a list
TextBox createdTextbox = new TextBox();
createdTextbox.TextChanged += createdTextbox_TextChanged;
listBox1.Items.Add(createdTextbox);
}
void createdTextbox_TextChanged(object sender, EventArgs e)
{
TextBox t = sender as TextBox;
if (t == null)
throw new ArgumentException("sender not of type TextBox", "sender");
//do something with t
}
}

You add textboxes the same way you do, this is my example (sorry it's vb.net):
Dim t As New TextBox With {.ID = "txt_123", .Text = "Vpiši"}
PlaceHolder1.Controls.Add(t)
t = New TextBox With {.ID = "txt_456", .Text = "Briši"}
PlaceHolder1.Controls.Add(t)
And then you iterate through controls in Placeholder (in my example):
Dim tItem As TextBox
Dim tValue As String = String.Empty
For Each c As Control In PlaceHolder1.Controls
If TypeOf c Is TextBox Then
tItem = c
tValue = tItem.Text.ToString
End If
Next
C# example added
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
TextBox t = new TextBox();
t.Text = "Vpiši";
t.ID = "txt_123";
PlaceHolder1.Controls.Add(t);
t = new TextBox();
t.Text = "Briši";
t.ID = "txt_456";
PlaceHolder1.Controls.Add(t);
}
}
protected void Button1_Click(object sender, EventArgs e)
{
TextBox tItem;
String tValue;
foreach (Control c in PlaceHolder1.Controls)
{
if (c.GetType() == typeof(TextBox))
{
tItem = (TextBox)c;
tValue = tItem.Text;
}
}
}

dynamically created controls disappears when click

the dynamic controls went missing right after i click it, why is this happening, and how do i fix it.
protected void Page_Load(object sender, EventArgs e)
{
/*DropDownList1_SelectedIndexChanged(sender, e);
Label1.Text += "<br/>huh?";
Label1.Text = MapPath("dawd");*/
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
//PlaceHolder1.Controls.Clear();
for (int i = 0; i < DropDownList1.SelectedIndex + 1; i++)
{
CheckBox cb = new CheckBox();
cb.AutoPostBack = true;
cb.CheckedChanged += new EventHandler(cb_CheckedChanged);
PlaceHolder1.Controls.Add(cb);
PlaceHolder1.Controls.Add(new LiteralControl("<br/>"));
}
}
void cb_CheckedChanged(object sender, EventArgs e)
{
//DropDownList1_SelectedIndexChanged(sender, e);
Label1.Text += "<br/>adsd";
//throw new NotImplementedException();
}
cheers, Jaf

Dynamically created controls have to be recreated in every postback, or they will not be available and non of their events will fire.
You are only ever adding the checkboxes when the dropdownlist changes, so any other postback will not add them.
It is best to create your dynamic controls on the page OnInit event.
Read about the page life cycle here.

Create a panel
Do not create on page_load
Add this code
protected override void CreateChildControls()
{
base.CreateChildControls();
loadCheckbox();
}
public void loadCheckbox()
{
int checkCount = 10;
CheckBox[] chk = new CheckBox[checkCount];
for(int i == 0; i<=10; i++)
{
chk[i] = new CheckBox();
chk[i].ID = rCmt.cmtkey;
chk[i].Text = rCmt.rootcommitteename;
Panel1.Controls.Add(chk[i]);
}
}