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ASP.NET - SelectedValue/Index in Listbox always changing after a postback

I've been wrestling with this problem for days and so far I haven't been able to find an answer that fits this specific issue. Here's the code to load the list in the PageLoad():
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
lstEmprendimientos.DataSource = Emprendimiento.DevolverEmprendimientosConEvaluacionesIncompletas();
lstEmprendimientos.DataValueField = "id";
lstEmprendimientos.DataTextField = "titulo";
lstEmprendimientos.DataBind();
pnlEvaluador.Visible = false;
}
}
The first method loads a list made up of 'Emprendimiento' objects, and on that list's SelectedIndexChanged I call another method to load a list through a method that uses the SelectedValue of the item selected.
My problem is that, no matter what I do, the SelectedIndex is always reset to 0 after a postback, so I can't load the second list using the SelectedValue properly. I've worked with lists for a long while now and I've never had this problem, so it's really baffling. I'd appreciate some help with this.
Here's the code for the whole page:
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
ddlEmprendimientos.DataSource = Emprendimiento.DevolverEmprendimientosConEvaluacionesIncompletas();
ddlEmprendimientos.DataValueField = "id";
ddlEmprendimientos.DataTextField = "titulo";
ddlEmprendimientos.DataBind();
pnlEvaluador.Visible = false;
}
}
protected void lstEmprendimientos_SelectedIndexChanged(object sender, EventArgs e)
{
}
protected void lstEvaluadores_SelectedIndexChanged(object sender, EventArgs e)
{
Evaluador ev = Evaluador.FindByID(lstEvaluadores.SelectedValue);
}
protected void btnAsignarEvaluador_Click(object sender, EventArgs e)
{
Emprendimiento emp = Emprendimiento.FindByID(Convert.ToInt32(ddlEmprendimientos.SelectedValue));
Evaluador ev = Evaluador.FindByID(lstEvaluadores.SelectedValue);
Evaluacion eva = new Evaluacion(emp, ev, 0, "justificacion", DateTime.Now, false);
if (eva != null)
{
if (eva.Insertar())
{
lblFeedback.Text = "Alta exitosa.";
emp.listaEvaluaciones.Add(eva);
lstEvaluadores.DataSource = emp.DevolverListaEvaluadoresQueNoEvaluanEmprendimiento();
lstEvaluadores.DataTextField = "Nombre";
lstEvaluadores.DataValueField = "Email";
lstEvaluadores.DataBind();
pnlEvaluador.Visible = true;
CargarEvaluadores();
}
else
{
lblFeedback.Text = "Error en el ingreso de datos.";
}
}
else
{
lblFeedback.Text = "Error en el ingreso de datos.";
}
}
protected void btnSeleccionarEmp_Click(object sender, EventArgs e)
{
CargarEvaluadores();
}
private void CargarEvaluadores()
{
Emprendimiento emp = Emprendimiento.FindByID(Convert.ToInt32(ddlEmprendimientos.SelectedIndex));
lstEvaluadores.DataSource = emp.DevolverListaEvaluadoresQueNoEvaluanEmprendimiento();
lstEvaluadores.DataTextField = "Nombre";
lstEvaluadores.DataValueField = "Email";
lstEvaluadores.DataBind();
pnlEvaluador.Visible = true;
}
protected void ddlEmprendimientos_SelectedIndexChanged(object sender, EventArgs e)
{
CargarEvaluadores();
}
Page markup:
<%Page Title="" Language="C#" MasterPageFile="~/masterPage.Master" AutoEventWireup="true" CodeBehind="asignarEvaluador.aspx.cs" Inherits="InterfazUsuario.asignarEvaluador">
<asp:DropDownList ID="ddlEmprendimientos" runat="server" OnSelectedIndexChanged="ddlEmprendimientos_SelectedIndexChanged">
</asp:DropDownList>
<br />
<br />
<asp:Button ID="btnSeleccionarEmp" runat="server" OnClick="btnSeleccionarEmp_Click" Text="Seleccionar emprendimiento" Width="195px" />
<br />
<br />
<asp:Panel ID="pnlEvaluador" runat="server">
<asp:ListBox ID="lstEvaluadores" runat="server" OnSelectedIndexChanged="lstEvaluadores_SelectedIndexChanged"></asp:ListBox>
<br />
<br />
<asp:Button ID="btnAsignarEvaluador" runat="server" OnClick="btnAsignarEvaluador_Click" Text="Asignar evaluador" Width="135px" />
<br />
<br />
<asp:Label ID="lblFeedback" runat="server"></asp:Label>
<br />
</asp:Panel>

You need to change your DropDownList and ListBox controls to AutoPostback
DropDownList
<asp:DropDownList ID="ddlEmprendimientos" runat="server"
OnSelectedIndexChanged="ddlEmprendimientos_SelectedIndexChanged"
AutoPostBack="True">
</asp:DropDownList>
ListBox
<asp:ListBox ID="lstEvaluadores" runat="server"
OnSelectedIndexChanged="lstEvaluadores_SelectedIndexChanged"
AutoPostBack="True">
</asp:ListBox>
AutoPostBack:
Set this property to true if the server needs to capture the selection
as soon as it is made. For example, other controls on the Web page can
be automatically filled depending on the user's selection from a list
control.
This property can be used to allow automatic population of other controls on > the Web page based on a user's selection from a list.
The value of this property is stored in view state.
https://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.listcontrol.autopostback(v=vs.110).aspx

I found the problem after checking everything out again.
The DataValueField in the list was 'id', and the id field in the 'Emprendimiento' class wasn't defined, so it was always returning a null int (0). Thank you kindly for the help, it was just a dumb mistake in the end.

Is it possible to populate same user control with different data on aspx?

I am looking for this over the internet but I am not getting any suitable answers. Here is my problem:
I have a web user control which has the following three controls
<asp:RadioButtonList ID="RadioButtonList1" runat="server" AutoPostBack="true"
CssClass="radioButton" RepeatDirection="Horizontal" RepeatLayout="Flow"
onselectedindexchanged="RadioButtonList1_SelectedIndexChanged" >
<asp:ListItem Value="UET111">Use Existing</asp:ListItem>
<asp:ListItem Value="CNT111">Create New</asp:ListItem>
</asp:RadioButtonList>
<asp:DropDownList ID="DropDownList1" runat="server" >
</asp:DropDownList>
<asp:TextBox ID="TextBox1" runat="server" C></asp:TextBox>
It's code behind
protected void Page_Load(object sender, EventArgs e)
{
DropDownList1.Visible = false;
TextBox1.Visible = false;
}
protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)
{
if (RadioButtonList1.SelectedItem.Value == "UET")
{
DropDownList1.Visible = true;
TextBox1.Visible = false;
}
else if (RadioButtonList1.SelectedItem.Value == "CNT")
{
DropDownList1.Visible = false;
TextBox1.Visible = true;
}
}
Now my question-
Actually I am using this web control 5 times on the same aspx page. The problem is I want to fill the dropdown list from aspx page and each dropdown will have different data(as I have 5 user control).
Is it possible to do that? Please help me with these and let me know if anyone knows a better way of doing this.

Create a public function in your user control that lets you send in a DataSource for the dropdown list to populate from, and if you want bind as well.
public BindDropdownDataSource(DataSet dataSource)
{
DropDownList1.DataSource = dataSource;
DropDownList1.DataBind();
}

enable an asp.net panel on dropdownlist onselectindexchanged

I want to enable a panel based on dropdownlist selected value.
protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddl.SelectedValue == "A")
{
lnk.Style.Add("Display", "block");
panel1.Visible=true;
panel1.Enabled=true;
}
}
The panel is not getting displayed. I have set autopastback property of dropdownlist to true.Can someone please help me.

should be without the quotes:
panel1.Enabled = true;
but if you wanted to show hide a panel:
<asp:Panel ID="panel1" runat="server" Visible="False" >
...
</asp:Panel>
then the right way would be
panel1.Visible = true;//false to hide

modal pop-up ok button not working as expected for a dropdown menu

CODE BEHIND:
private void Page_Load(object sender, System.EventArgs e)
{
if (!Page.IsPostBack)
{
ddlLanguage.SelectedValue = Thread.CurrentThread.CurrentCulture.Name;
}
}
protected void ddlLanguage_SelectedIndexChanged(object sender, EventArgs e)
{
if (ddlLanguage.SelectedValue == "es-ES")
{
mdlPopup.Show();
}
//Sets the cookie that is to be used by Global.asax
HttpCookie cookie = new HttpCookie("CultureInfo");
cookie.Value = ddlLanguage.SelectedValue;
Response.Cookies.Add(cookie);
//Set the culture and reload the page for immediate effect.
//Future effects are handled by Global.asax
Thread.CurrentThread.CurrentCulture = new CultureInfo(ddlLanguage.SelectedValue);
Thread.CurrentThread.CurrentUICulture = new CultureInfo(ddlLanguage.SelectedValue);
//Server.Transfer(Request.Path);
}
protected void OKButton_Click(object sender, EventArgs e)
{
Server.Transfer(Request.Path);
}
ASPX PAGE:
<asp:DropDownList ID="ddlLanguage" class="langpnl" runat="server" AutoPostBack="True"
OnSelectedIndexChanged="ddlLanguage_SelectedIndexChanged">
<asp:ListItem Value="en-US">Eng</asp:ListItem>
<asp:ListItem Value="es-ES">Esp</asp:ListItem>
</asp:DropDownList>
<ajaxToolkit:ModalPopupExtender ID="mdlPopup" runat="server" TargetControlID="testhidden"
PopupControlID="pnlPopup" OkControlID="OKButton" />
<asp:Panel ID="pnlPopup" runat="server" Width="500px" Style="display: none">
All content may not be in Spanish.
<asp:Button ID="OKButton" runat="server" Text="OK" OnClick="OKButton_Click" />
</asp:Panel>
<asp:HiddenField ID="testhidden" runat="server" />
I am trying to set the language as per the selection in the Dropdown box. But if the user selects spanish I want to display a popup modal with a msg & once the button OK is pressed I want to postback the whole page.
Currently I am able to display the popup but the page never refreshed so the language still doesn't change. In the code behind if I remove the server.transfer from the OK button and put it in the SelectIndexChange then the page postback is working but there is no popup masg .I think the page gets postback after the popup executes so it never gets displayed...please need some help I am breaking my head since last 3 days.

Define another button in that panel... and do whatever you want in his onclick event. So you will have a postback.
The OKButton click event... OKButton_Click will not fire as long as you assigned him in you modalpopup...

if (ddlLanguage.SelectedValue == "es-ES")
{
mdlPopup.Show();
}
else
{
Server.Transfer(Request.Path);
}
& removed the OK button from Modalpopup..finally got to see what I was Expecting..

Getting control value when switching a view as part of a multiview

I have the following code in my aspx page:
<asp:Button id="display_button" runat="server" Text="Display" OnClick="Button1_Click" />
<asp:Button id="edit_button" runat="server" Text="Edit" OnClick="Button2_Click" />
<asp:Button id="save_button" runat="server" Text="Save" OnClick="Button3_Click" Visible="false" />
<asp:MultiView id="MultiView1" runat="server" ActiveViewIndex="0">
<asp:View id="View1" runat="server">
<asp:FormView id="view_program" runat="server">
<ItemTemplate>
<%# Eval("status").ToString().Trim() %>
</ItemTemplate>
</asp:FormView>
</asp:View>
<asp:View id="View2" runat="server">
<asp:FormView id="edit_program" runat="server">
<ItemTemplate>
<asp:DropDownList id="p_status" runat="server">
</asp:DropDownList>
</ItemTemplate>
</asp:FormView>
</asp:View>
</asp:MultiView>
and the following functions attached to the buttons in the code-behind page:
protected void Button1_Click(object sender, EventArgs e)
{
MultiView1.SetActiveView(View1);
save_button.Visible = false;
}
protected void Button2_Click(object sender, EventArgs e)
{
MultiView1.SetActiveView(View2);
save_button.Visible = true;
}
protected void Button3_Click(object sender, EventArgs e)
{
DropDownList p_status = edit_program.FindControl("p_status") as DropDownList;
var status = p_status.SelectedValue;
Label1.Text = status;
//save_button.Visible = false;
//MultiView1.SetActiveView(View1);
}
The idea being, that there are two views, the first displays the information, if the user wants to edit the information, they click button 2 which changes the view to the edit mode, which has the controls (drop downs, text fields, etc). It also makes the 'save' button appear.
What I am trying to make happen is, when the save button is clicked, it will grab all of the values from the various fields, update the object and then update the database. Then it would flip back to view1 with the updated info.
Problem is, as you can see in void Button3_Click, I try grab the values from the control, p_status, but it only gets the original value. example, the menu has three values, 'Green', 'Yellow', and 'Red'. Green is the default value and is selected when view2 is displayed. However, if I select Yellow or Red, and click save, rather than the label being updated to display one of those two values, it always displays Green.
Any ideas?
edit: page load function per request below
protected void Page_Load(object sender, EventArgs e)
{
try
{
Person myPerson = new Person(userid);
TestProgram myProgram = new TestProgram(id);
List<TestProgram> program = new List<TestProgram> { myProgram };
view_program.DataSource = program;
view_program.DataBind();
edit_program.DataSource = program;
edit_program.DataBind();
DropDownList p_status = edit_program.FindControl("p_status") as DropDownList;
p_status.Items.Add(new ListItem("Green", "Green"));
p_status.Items.Add(new ListItem("Yellow", "Yellow"));
p_status.Items.Add(new ListItem("Red", "Red"));
//myProgram.Status = "Red";
p_status.SelectedValue = myProgram.Status;
}
catch (Exception ex)
{
Response.Write(ex);
Label1.Text = ex.ToString();
}
}

Whoops...missed a little someting.. my
bad
when asp.net is not behaving as expected this is your best friend: MSDN: ASP.NET PAGE LIFECYLE
Upon Further Review...
there are a couple of problems here. your drop down list control with an id of "p_status" is contained inside a multiview (I forgot about what that meant...) you need to move the code to populate p_status into pre-render after checking to see if Multiveiw1.ActiveView = View2. Since it will always be a post back you need to bind values late in the page cycle