Develop Reference

Get text/value from textbox after value/text changed server side

I have a FormView with data(DataSource,DataBind) that I fill with value='<%# Eval("Name") %>' , but after I'm changing the text in TextBox and press update button I see the same value that before, I cant see new value that I have typed.
What I am missing here?
my html
<asp:FormView ID="MainFormTemplate" runat="server">
<ItemTemplate>
<li class="li_result" runat="server">
<div class="col-3">
<input id="txt_Name" runat="server" value='<%# Eval("Name") %>'>
</div>
</li>
</ItemTemplate>
</asp:FormView>
<asp:Button id="btn_Update" runat="server" OnClick="btn_Update_Click" Text="Update" />
Server side
protected void Page_Load(object sender, EventArgs e)
{
using (DB_MikaDataContext data = new DB_MikaDataContext())
{
MainFormTemplate.DataSource = data.File_Projects.Where(x => x.Num_Tik.Equals("12")).ToList();
MainFormTemplate.DataBind();
}
}
public void btn_Update_Click(object sender, EventArgs e)
{
//using System.Web.UI.HtmlControls
HtmlInputText twt = (HtmlInputText)MainFormTemplate.FindControl("txt_Name");
string text = twt.Value;//i see old value ,not new one that i typed in text box
}

In every postback, you are always getting the old value from your database. The solution is check if the page is being rendered for the first time (!IsPostBack) then set your MainFormTemplate's DataSource else if is being loaded in response to a postback (IsPostBack) get the txt_Name's value like this:
HtmlInputText twt;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
using (DB_MikaDataContext data = new DB_MikaDataContext())
{
MainFormTemplate.DataSource = data.File_Projects.Where(x => x.Num_Tik.Equals("12")).ToList();
MainFormTemplate.DataBind();
}
}
else
{
twt = MainFormTemplate.FindControl("txt_Name") as HtmlInputText;
}
}
protected void btn_Update_OnClick(object sender, EventArgs e)
{
string text = twt.Value; // You will get the new value
}

with Page_Load executing every postback, you are always writing value from database (?), and value sent from browser is lost (although still exist in Page.Request.Form member).

In ASP.NET, When a page is submitted, the Page_Load event runs before the button click event. So, the textbox value gets repopulated with its original value before the click event looks at that value.
If this is the situation, then you can wrap the code that assigns the value to the textbox in an if block like this:
if (!IsPostBack)
{
HtmlInputText twt = (HtmlInputText)MainFormTemplate.FindControl("txt_Name");
string text = twt.Value;
}
Hope this helps you.

Change div things in other page

I used the code below to make a change in div of the page of this code file:
HtmlGenericControl divTest = Page.FindControl("test") as HtmlGenericControl;
divTeste.InnerText = "tested";
But now, I want to change another page. Ex.: default.aspx code behind changes a div inner text in the test.aspx ...
The code above isn't appropriated. I want permanent changes. What code should be?
How can I do it?

You need to understand how ASP.NET works. Introduction to ASP.NET
If you are on Default.aspx and then wont to move to Test.aspx you can use values from Default.aspx in Test.aspx however you can't just change different pages from the page you are on. (Actually it is possible by writing data to a database and then later accessing that data on the page you want to change but for your example I don't believe you are looking for something like that)
The closest to your example I can think of is using a Query string.
Default.aspx Markup
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
Default.aspx Code behind
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("Test.aspx?DivMSG=Hello");
}
Test.aspx Markup
<div id="MyTestDiv" runat="server">
</div>
Test.aspx Code Behind
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
MyTestDiv.InnerText = Request.QueryString["DivMSG"];
}
}
Update:
One way to make it permanent is to write it to a database. A quick example but you need to do the database code
Default.aspx Markup
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
Default.aspx Code behind
protected void Button1_Click(object sender, EventArgs e)
{
string messageToWriteToTestDiv = TextBox1.Text;
// Code: to write messageToWriteToTestDiv to the database
}
Test.aspx Code Behind
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
string myMessage = "";
// Code: string myMessage = Get Message from Database to write to div
MyTestDiv.InnerText = myMessage;
}
}
Test.aspx Markup
<div id="MyTestDiv" runat="server">
</div>

Refreshing UpdatePanel after click event of a Button inside a modalpopup inside a UserControl

I have a page with a listbox and a user control placed inside an update panel like this:
<%# Register TagPrefix="uc1" TagName="CMessage" Src="~/Controls/CMessage.ascx" %>
<ajaxToolkit:ToolkitScriptManager runat="server" ID="ToolkitScriptManager1" EnableScriptGlobalization="true" EnableScriptLocalization="true" />
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:ListBox ID="lbox" runat="server"></asp:ListBox>
<asp:Button ID="btnDelete" OnClick="btnDelete_Click" runat="server" Text="Delete selected item" Enabled="True"></asp:Button>
<uc1:CMessage ID="CMessage1" runat="server" />
</ContentTemplate>
</asp:UpdatePanel>
The page codebehind is like this:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
lbox.Items.Add("test1");
lbox.Items.Add("test2");
}
}
protected void btnDelete_Click(object sender, EventArgs e)
{
CMessage.MessageConfirm("Delete item?", "Yes", "No", DeleteItem);
}
protected void DeleteItem()
{
lbox.Items.Remove(lbox.SelectedItem);
CMessage.Message("Item deleted succesfully!");
}
The user control is like this:
<%# Control Language="C#" AutoEventWireup="true" CodeFile="CMessage.ascx.cs" Inherits="Controles.CMessage" %>
<table id="tableMessage" runat="server" style="display: none" class="modalPopup">
<tr>
<td>
<asp:Label ID="lb5" runat="server" Text="Message"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="lbMessage" runat="server"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Button ID="btnOk" runat="server" Text="Ok" OnClick="btnOk_Click" />
<asp:Button ID="btnCancel" runat="server" Text="Cancel" OnClick="btnCancel_Click" />
</td>
</tr>
</table>
<asp:Button ID="btnOKError" runat="server" Text="OK" style="display: none" />
<ajaxToolkit:ModalPopupExtender ID="ModalPopupMessage" runat="server" TargetControlID="btnOKError" PopupControlID="tableMessage" OkControlID="btnOKError" CancelControlID="btnOKError"></ajaxToolkit:ModalPopupExtender>
The usercontrol codebehind is like this:
public partial class CMensaje : UserControl
{
public delegate void FunctionButtonPressed();
private FunctionButtonPressed FunctionButtonPressedOk
{
get { return (FunctionButtonPressed)Session["FunctionButtonPressedOk"]; }
set { Session["FunctionButtonPressedOk"]= value; }
}
protected void btnOk_Click(object sender, EventArgs e)
{
ModalPopupMenssage.Hide();
if (FunctionButtonPressedOk!= null)
{
FunctionButtonPressedOk();
}
}
protected void btnCancel_Click(object sender, EventArgs e)
{
ModalPopupMessage.Hide();
}
public void Mensaje(string message)
{
lbMessage.Text = message;
FunctionButtonPressedOk= null;
btnCancel.Visible = false;
ModalPopupMessage.Show();
}
public void MessageConfirm(string message, FunctionButtonPressed FunButtonOkx)
{
lbMessage.Text = message;
FunctionButtonPressedOk= FunBotonAceptarx;
btnCancel.Visible = true;
ModalPopupMensaje.Show();
}
}
Everything works, the popup is shown, the function to call from the page is passed to the usercontrol to trigger it if the user presses ok and triggers correctly etc. But in that last function DeleteItem() the changes done to the page (in this example the item removed from the listbox and the notification message launched) doesnt work.
Its like the updatepanel doesnt refresh. I cant call manually UpdatePanel1.Update() because i have the updatemode as always. In theory in this part of the pagecycle it should refresh the pages with the changes...
I tried adding in the user control pageload the OK button as a PostBackTrigger of the UpdatePanel with no avail and as an AsyncPostBackTrigger.
Keep in mind that this is an slimmed down version of the page and the user control so people can focus on the problem at hand so if you need any more details ask me...
The code flow is like this:
User clicks in the delete item button and triggers the
btnDelete_Click() in the page (first postback)
btnDelete_Click() calls the usercontrol CMessage.MessageConfirm passing DeleteItem as
argument
At the usercontrol MessageConfirm() shows the modalpopup and saves
the argument function DeleteItem() in order to call it later(end of
first postback)
After displaying the modalpopup the user clicks its Ok button and
triggers the btnOk_Click() in the usercontrol (second postback)
At the usercontrol btnOk_Click() calls the DeleteItem() function
that was saved previously
At the page DeleteItem() removes the item from the ListBox (lets say
i dont call the second message to simplify, this would be the end of
the second postback, and the update panel hasnt refreshed :S)
I think i have isolated the problem, moved all the controls and functions from the usercontrol to the page, the problem persisted, but if i called the DeleteItem() function directly instead of his delegate it worked (keep in mind that in both cases the breakpoint at DeleteItem() triggered so the function code was executing correctly):
protected void btnOk_Click(object sender, EventArgs e)
{
ModalPopupMenssage.Hide();
/*if (FunctionButtonPressedOk!= null)
{
FunctionButtonPressedOk();
}*/
DeleteItem(); //page updates correctly! why?
}
Is there some incompatibility with delegates?

In the end i solved it changing the following lines:
if (FunctionButtonPressedOk!= null)
{
//FunctionButtonPressedOk();
Page.GetType().InvokeMember(FunctionButtonPressedOk.Method.Name, BindingFlags.InvokeMethod, null, Page, new []{sender, e});
}
Why it works this way?Whats the difference internally?

LinkButton not working within UpdatePanel

I'm building a table of data for price quotes (think table of Stock quotes) which needs to be refreshed every 5 secs. Each row has some data about one Stock in several columns and the last column in each row has a LinkButton to see more info about that particular stock. Everything works but the LinkButton. The entire table is nested inside an UpdatePanel which I think is causing the problem. I've seen a fair number of posts on this topic but none that have worked for me.
Here is my .aspx code:
<asp:ScriptManager ID="ScriptManager" runat="server" />
<asp:Timer ID="Timer" OnTick="Timer_Tick" runat="server" Interval="5000" />
<div id="itemList">
<asp:UpdatePanel ID="itemPanel" UpdateMode="Conditional" ChildrenAsTriggers="false" runat="server">
<Triggers><asp:AsyncPostBackTrigger ControlID="Timer" /></Triggers>
<ContentTemplate>
<asp:Panel ID="Panel_ItemList" runat="server" width="100%"></asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</div>
and my .aspx.cs code:
protected void Page_Load(object sender, EventArgs e)
{
...
if (!Page.IsPostBack)
{
updateItemsTable();
}
}
protected void LinkButton_Click(object sender, CommandEventArgs e)
{
Panel_LoginAlert.Visible = true; // <-- THIS IS NOT FIRING!!
}
protected void Timer_Tick(object sender, EventArgs e)
{
updateItemsTable();
}
protected void updateItemsTable()
{
//... Query my DB
if (rdr.HasRows)
{
Panel_ItemList.Controls.Add(new LiteralControl("<!-- ItemList Panel -->\n"));
while (rdr.Read())
{
LinkButton lb = new LinkButton();
lb.Text = "Item";
lb.ID = "lbItem_" + strDBitemID;
lb.CommandName = strDBitemName;
lb.CommandArgument = strDBitemID;
lb.Command += new CommandEventHandler(LinkButton_Click);
Panel_ItemList.Controls.Add(lb);
}
Panel_ItemList.Controls.Add(new LiteralControl("<!-- END ItemList Panel -->\n"));
}
//...
conn.Close();
}
So the page loads fine and the timer reloads the table fine, but the LinkButtons do not fire the CommandEventHandler. This works fine if I remove the Timer.
Things I've tried:
I tried using Buttons rather than LinkButtons but this didn't help.
I read dozens of posts saying to add an ID to the LinkButton controls, but this didn't help either.

I believe the problem is when your adding the controls. For this to work the server controls need to be added in the Init event, or overriding OnInit(EventArgs).
Instead of explicitly creating the controls you could replace the panel with a repeater. Then bind your results from the database to the reader.
<asp:Repeater ID="TheRepeater" ...>
<ItemTemplate>
<asp:LinkButton onClick="LinkButton_Click" ...bind values to properties here />
</ItemTemplate>
</asp:Repeater>
code behind
TheRepeater.Visible = rdr.HasRows;
TheRepeater.DataSource = rdr;
TheRepeater.DataBind();
That being said, if all you want to do is alter the UI, that could easily be accomplished with jquery.

I believe the problem is in the page life cycle, since you are creating a dynamic control and adding the event after the page_init or page_load, its not getting hooked up correctly to the control, you could try out the following and see if it works:
Add page init:
protected void Page_Init(object sender, EventArgs e)
{
updateItemsTable();
}
and change the timer tick event to:
protected void Timer_Tick(object sender, EventArgs e)
{
itemPanel.Update();
}
and that should do the trick.
Hope this is of help.
Cheers.

You need to add postback trigger as following:
<asp:PostBackTrigger ControlID="SearchBrn"/>

Image.ImageUrl not working (C#, asp.net)

I have the next code:
<asp:ListView ID="LV1" runat="server" DataSourceID="LinqDataSource">
<ItemTemplate>
<asp:Image ID="Image1" Width="100px" Height="100px" runat="server" />
//....and so on till the
</asp:ListView>
The code behind:
protected void checkTheImage()
{
foreach (ListViewItem item in LV1.Items)
{
((Image)item.FindControl("Image1")).ImageUrl = "~/noImage.jpg";
}
}
And page load:
protected void Page_Load(object sender, EventArgs e)
{
checkTheImage();
}
The problem is - the noImage.jpg is not display... why ?

not sure if your markup is ok, you should also have a closing ItemTemplate tag somewhere... please update your markup.
just to try out things, does it work if you move the call of checkTheImage(); inside the Page_PreRender?
is there any place where you DataBind the ListView in your page life cycle?

May be you need to rebind the ListView.
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
LV1.DataBind();
checkTheImage();
}
}