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Dynamically added dropdownlist losing value on postback

Hi i am creating dropdownlist dynamically but on post back it is loosing the value and i am unable to get values on button click event.
private void CreateDropdownListEmployee(string id,Panel pnl, DataTable dt)
{
DropDownList drp = new DropDownList();
drp.ID = id;
drp.CssClass = "activeuserTxt";
drp.ClientIDMode = ClientIDMode.Static;
drp.DataSource = dt;
drp.DataTextField = "name";
drp.DataValueField = "id";
drp.DataBind();
pnl.Controls.Add(drp);
}
For the dynamic texbox i am using the below code on PAge_Init
protected void Page_Init(object sender, EventArgs e)
{
try
{
int SNID = 0;
List<string> keysNetmr = Request.Form.AllKeys.Where(key => key.Contains("txt")).ToList();
foreach (string key in keysNetmr)
{
this.CreateTextBox("txtNermr" + SNID, 100, pnlSN);
SNID++;
}
}
catch (Exception ex) { }
}
private void CreateTextBox(string id, int width, Panel pnl)
{
TextBox txt = new TextBox();
txt.ID = id;
txt.Width = width;
txt.Attributes.Add("autocomplete", "off");
txt.CssClass = "activeuserTxt";
pnl.Controls.Add(txt);
}
Can anyone help me on this.

C# Drop Down List Not Trigger index changing

I select one value on the ddl , and it does not show the products in the page. The selected value remains binded but the page is blank.
Also , if I just call function getCat() without using if(!ispostback). When i load the page the drop down list is stuck on the first value , but it shows the products in page.
Drop Down List:
<asp:dropdownlist runat="server" id="ddcateg" AutoPostBack="true" onselectedindexchanged="Ddcateg_SelectedIndexChanged"></asp:dropdownlist>
This is the implementation:
protected void Page_Load(object sender, EventArgs e)
{
//afisare();
if (!IsPostBack)
{
getCateg();
}
}
public void getCateg()
{
ProdusTipModel model = new ProdusTipModel();
FarmacieEntities db = new FarmacieEntities();
var lizt = (from c in db.ProdusTips select c).ToList();
ddcateg.DataSource = lizt;
ddcateg.DataValueField = "ID";
ddcateg.DataTextField = "Name";
ddcateg.DataBind();
ddcateg.SelectedIndexChanged += Ddcateg_SelectedIndexChanged;
}
public void afisare2(List<Produ> z)
{
ProdusModel mdl = new ProdusModel();
foreach (var produs in z)
{
Panel produsePnl = new Panel();
ImageButton imageButton = new ImageButton();
produsePnl.BorderColor = Color.AliceBlue;
Label lblNume = new Label();
Label lblPret = new Label();
produsePnl.BorderStyle = BorderStyle.Groove;
produsePnl.BorderColor = Color.LightSkyBlue;
imageButton.ImageUrl = "~/Img/Produse/" + produs.Image;
imageButton.CssClass = "imgProdus";
imageButton.PostBackUrl = "~/Pages/PaginaProdus.aspx?id=" + produs.ID;
lblNume.Text = produs.Name;
lblNume.CssClass = "numeProd";
lblPret.Text = produs.Price + "lei";
lblPret.CssClass = "produsPret";
produsePnl.Controls.Add(imageButton);
produsePnl.Controls.Add(new Literal { Text = "<br /" });
produsePnl.Controls.Add(lblNume);
produsePnl.Controls.Add(new Literal { Text = "<br /" });
produsePnl.Controls.Add(lblPret);
pnlProduse.Controls.Add(produsePnl);
}
}
private void Ddcateg_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList selectedList = (DropDownList)sender;
int selectedLit = Convert.ToInt32(selectedList.SelectedValue);
ProdusModel mdl = new ProdusModel();
List<Produ> list = mdl.GetProdCateg(selectedLit).ToList();
afisare2(list);
}

Your problem could be that your code behind method is private:
private void Ddcateg_SelectedIndexChanged(object sender, EventArgs e)
Try making it protected or public so it can be seen by the aspx page.

ASP.NET Textbox losing values after postback which were set during editing

There's a gridview in my program whose row's data is to be loaded in textboxes if edit is clicked.
Here is the code where I'm filling the data in textboxes after edit is clicked
protected void GV_Parameters_RowEditing(object sender, GridViewEditEventArgs e)
{
GV_Parameters.EditIndex = e.NewEditIndex;
int index = e.NewEditIndex;
IsEditing = true;
Label lbl_frmdate = (Label)GV_Parameters.Rows[index].FindControl("lbl_frmdate") as Label;
Label lbl_todate = (Label)GV_Parameters.Rows[index].FindControl("lbl_todate") as Label;
EditFromDate = lbl_frmdate.Text.ToUpper();
lbl_frm_edit.Text = EditFromDate;
EditToDate = lbl_todate.Text.ToUpper();
lbl_to_edit.Text = EditToDate;
Label lbl = (Label)GV_Parameters.Rows[index].Cells[3].FindControl("lbl_Is_holiday");
string is_holiday = lbl.Text;
Label lbl_std_intime = (Label)GV_Parameters.Rows[index].FindControl("lbl_std_intime") as Label;
Label lbl_std_outtime = (Label)GV_Parameters.Rows[index].FindControl("lbl_std_outtime") as Label;
string[] arr_std_intime;
string[] arr_std_outtime;
if (is_holiday != "1")//working day
{
r_work_holiday.SelectedIndex = 0;
IsHoliday = false;
if (lbl_std_intime.Text != "")
{
arr_std_intime = lbl_std_intime.Text.Split(':');
txt_std_TimeInHours.Text = arr_std_intime[0].ToString();
txt_std_TimeInMins.Text = arr_std_intime[1].ToString();
}
if (lbl_std_outtime.Text != "")
{
arr_std_outtime = lbl_std_outtime.Text.Split(':');
txt_std_TimeOutHours.Text = arr_std_outtime[0].ToString();
txt_std_TimeOutMins.Text = arr_std_outtime[1].ToString();
}
}
else
{
IsHoliday = true;
//r_workingday.Checked = false;
//r_holiday.Checked = true;
r_work_holiday.SelectedIndex = 1;
Label lbl_remarks = (Label)GV_Parameters.Rows[index].FindControl("lbl_remarks") as Label;
txt_holiday_desc.Text = lbl_remarks.Text;
}
collapse_state = "expand";
}
There is a radiobutton list who shows the edited row is holiday or working day,
if user changes the selection in radioButtonList, PostBack occurs and this is the time when all of the texboxes turn blank.
protected void r_work_holiday_SelectedIndexChanged(object sender, EventArgs e)
{
if(r_work_holiday.SelectedIndex==0)
{
IsHoliday = false;
}
else
{
IsHoliday = true;
}
collapse_state = "expand";
}
There's no any method in page load who is clearing the textboxes.
protected void Page_Load(object sender, EventArgs e)
{
if (IsEditing)
{
collapse_state = "expand";
}
if (!Page.IsPostBack)
{
BindYears();
}
}
Please help
Update ::
lbl_frm_edit and lbl_to_edit are not getting reset after postback.
The variable EditFromDate and EditToDate are being set by Viewstate

It's been sometime I worked in ASP controls but if I remember correctly, the content in textboxes are generally cleared on every post back by ASP .NET. The state of the textboxes are not saved.
Here is an answer I found while researching this issue.
You could store the value of the textboxes in ViewState and assign them back on the PageLoad event. Something like
txt_std_TimeOutHours.Text = arr_std_outtime[0].ToString();
txt_std_TimeOutMins.Text = arr_std_outtime[1].ToString();
ViewState["TimeOutHours"] = arr_std_outtime[0].ToString();
ViewState["TimeOutMins"] = arr_std_outtime[1].ToString();
And on the PageLoad event you can do this to restore the values.
if(Page.IsPostBack)
{
txt_std_TimeOutHours.Text = ViewState["TimeOutHours"].ToString();
txt_std_TimeOutMins.Text = ViewState["TimeOutMins"].ToString();
}
Hope this helps!

ASP.NET GridView does not update its row

I followed this tutorial on MSDN for ASP.NET GridView Update Row, but it does not work.
updatedItem.DepartureCity = ((TextBox)(row.Cells[2].Controls[0])).Text;
Still gives the original value from the cell and not the updated one.
public partial class ManagePage : System.Web.UI.Page
{
BusScheduleModelContainer modelContainer = new BusScheduleModelContainer();
protected void Page_Load(object sender, EventArgs e)
{
//FormsAuthentication.RedirectFromLoginPage()
//if (!HttpContext.Current.User.Identity.IsAuthenticated)
//{
// Server.Transfer("LoginPage.aspx");
//}
resultsGridView.DataSource = modelContainer.BusRoutes.ToList();
resultsGridView.DataBind();
}
protected void RowDeleting(object sender, GridViewDeleteEventArgs e)
{
var routeID = int.Parse(e.Values[0].ToString());
var removedItem = modelContainer.BusRoutes.FirstOrDefault(
item => item.RouteID == routeID);
if (removedItem != null)
{
modelContainer.BusRoutes.Remove(removedItem);
resultsGridView.DataSource = modelContainer.BusRoutes.ToList();
resultsGridView.DataBind();
modelContainer.SaveChanges();
}
}
protected void RowUpdating(object sender, GridViewUpdateEventArgs e)
{
var routeID = int.Parse(e.NewValues[0].ToString());
var updatedItem = modelContainer.BusRoutes.FirstOrDefault(
item => item.RouteID == routeID);
if (updatedItem != null)
{
GridViewRow row = resultsGridView.Rows[e.RowIndex];
var res = row.FindControl("ctl00$ContentPlaceHolder1$resultsGridView$ctl02$ctl03");
updatedItem.DepartureCity = ((TextBox)(row.Cells[2].Controls[0])).Text;
updatedItem.ArrivalCity = ((TextBox)(row.Cells[3].Controls[0])).Text;
updatedItem.DepartureTime = DateTime.Parse(((TextBox)(row.Cells[4].Controls[0])).Text);
updatedItem.ArrivalTime = DateTime.Parse(((TextBox)(row.Cells[5].Controls[0])).Text);
}
resultsGridView.EditIndex = -1;
BindData();
}
protected void RowEditing(object sender, GridViewEditEventArgs e)
{
//Set the edit index.
resultsGridView.EditIndex = e.NewEditIndex;
//Bind data to the GridView control.
BindData();
}
protected void RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
//Reset the edit index.
resultsGridView.EditIndex = -1;
//Bind data to the GridView control.
BindData();
}
private void BindData()
{
resultsGridView.DataSource = modelContainer.BusRoutes.ToList();
resultsGridView.DataBind();
}
}
<div>
<asp:GridView runat="server" ID="resultsGridView"
AutoGenerateColumns="true" AllowPaging="true"
AutoGenerateDeleteButton="true" OnRowDeleting="RowDeleting"
AutoGenerateEditButton="true" OnRowUpdating="RowUpdating"
OnRowEditing="RowEditing" OnRowCancelingEdit="RowCancelingEdit">
</asp:GridView>
</div>

Do you use CommandField for update controler?
If so, when you click update button, first it will do Page_Load event handler, after that do the implementation in RowUpdating event handler.
You should try to check post back in Page_Load event handler like this:
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
resultsGridView.DataSource = modelContainer.BusRoutes.ToList();
resultsGridView.DataBind();
}
}
By this way, it will bind data to the GridView only first time you open this page.
For post back event such as clicking update button, it will not bind the original data to GridView again.

In RowUpdating method you need to add modelContainer.SaveChanges(); like below:
if (updatedItem != null)
{
GridViewRow row = resultsGridView.Rows[e.RowIndex];
var res = row.FindControl("ctl00$ContentPlaceHolder1$resultsGridView$ctl02$ctl03");
updatedItem.DepartureCity = ((TextBox)(row.Cells[2].Controls[0])).Text;
updatedItem.ArrivalCity = ((TextBox)(row.Cells[3].Controls[0])).Text;
updatedItem.DepartureTime = DateTime.Parse(((TextBox)(row.Cells[4].Controls[0])).Text);
updatedItem.ArrivalTime = DateTime.Parse(((TextBox)(row.Cells[5].Controls[0])).Text);
modelContainer.SaveChanges();
}

Gridview Edit/Update is not working?

Here i am updating the gridview value but the value is not updating..TextBox txtID,TextBox txtName,TextBox txtAge retains the older value only and the value is not getting updated..Can anyone tel me like what am i doing wrong here
Here is my code
protected void gvTemp_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
CreateDataSkeletton(Convert.ToInt16(Session["intTabIndex"]));
GridViewRow row = (GridViewRow)gvTemp.Rows[e.RowIndex];
int autoid = Int32.Parse(gvTemp.DataKeys[e.RowIndex].Value.ToString());
int id = Convert.ToInt32(gvTemp.DataKeys[e.RowIndex].Values[0].ToString());
activeTabIndex = Convert.ToInt16(Session["activeTabIndex"]);
TextBox txtID = ((TextBox)gvTemp.Rows[e.RowIndex].FindControl("txtId"));
TextBox txtName = (TextBox)gvTemp.Rows[e.RowIndex].FindControl("txtName");
TextBox txtAge = (TextBox)gvTemp.Rows[e.RowIndex].FindControl("txtAge");
dataSetInSession.Tables["Days" + activeTabIndex.ToString()].Rows[e.RowIndex]["ID"] = txtID.Text;
dataSetInSession.Tables["Days" + activeTabIndex.ToString()].Rows[e.RowIndex]["Name"] = txtName.Text;
dataSetInSession.Tables["Days" + activeTabIndex.ToString()].Rows[e.RowIndex]["Age"] = txtAge.Text;
gvTemp.DataSource = dataSetInSession.Tables["Days" + activeTabIndex.ToString()];
gvTemp.DataBind();
gvTemp.EditIndex = -1;
}
and
private void CreateDataSkeletton(int intTabIndex)
{
dataSetInSession = new DataSet();
Session["intTabIndex"] = intTabIndex;
if (Session["dataSetInSession"] != null)
{
dataSetInSession = (DataSet)Session["dataSetInSession"];
}
if (dataSetInSession.Tables["Days" + intTabIndex].Rows.Count > 0)
{
gvTemp.DataSource = dataSetInSession.Tables["Days" + intTabIndex];
gvTemp.DataBind();
}
else
{
gvTemp.DataSource = dataSetInSession.Tables["Days"];
gvTemp.DataBind();
}
temp.Controls.Add(gvTemp);
}
Any suggestion??
EDIT(1):
protected void Page_Init(object sender, EventArgs e)
{
if (!IsPostBack)
{
AddDataTable();
}
dataSetInSession = new DataSet();
if (Session["dataSetInSession"] != null)
{
dataSetInSession = (DataSet)Session["dataSetInSession"];
}
if (Session["dynamicTabIDs"] != null)
{
//if dynamicTabIDs are in session, recreating the Tabs
//that are associated with the Tab IDs
//and adding them to the TabContainer that will contain
//all of the dynamic tabs.
//retrieving the tab IDs from session:
dynamicTabIDs = (List<string>)Session["dynamicTabIDs"];
if (TabContainerContent.ActiveTabIndex == -1)
{
TabContainerContent.ActiveTabIndex = Convert.ToInt16(Session["intTabIndex"]);
}
CreateDataSkeletton(Convert.ToInt16(Session["intTabIndex"]));
//looping through each TabID in session
//and recreating the TabPanel that is associated with that tabID
foreach (string tabID in dynamicTabIDs)
{
//creating a new TabPanel that is associated with the TabID
AjaxControlToolkit.TabPanel tab = new AjaxControlToolkit.TabPanel();
//TabContainerContent.ActiveTabIndex = tab;
//Setting the ID property of the TabPanel
tab.ID = tabID;
//setting the TabPanel's HeaderText
tab.HeaderText = "Days " + (TabContainerContent.Tabs.Count + 1).ToString();
//creating a Label to add to the TabPanel...at this point you'll have to
//create whatever controls are required for the tab...
Label tabContent = new Label();
//Giving the Label an ID
tabContent.ID = "lbl_tab_" + TabContainerContent.Tabs.Count.ToString();
//Setting the Label's text
tabContent.Text = "Tab " + (TabContainerContent.Tabs.Count + 1).ToString();
//Adding the Label to the TabPanel
tab.Controls.Add(tabContent);
//Adding the TabPanel to the TabContainer that contains the dynamic tabs
TabContainerContent.Tabs.Add(tab);
}
}
else
{ //Creating a new list of dynamicTabIDs because one doesn't exist yet in session.
dynamicTabIDs = new List<string>();
}
}
protected void Page_Load(object sender, EventArgs e)
{
}

Read Page Life Cycle
And you will get, that if you want to bind in code-behind, you should do it in Init Event, other wise there are no events will fire.

It seems to be Page.IsPostback problem.Need to add Page.IsPostback property in your page_load like
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
// Put your code inside that.
}
}
Actually your control is getting new value but when you click for updation then it calls old value from page_load.So try to put Page.IsPostback into your page_load event,Just like i mentioned.
I hope it helps.