Web Forms :: Dynamic Control Added To PlaceHolder Disappears On Button Click?
Nov 16, 2010
I have a dropdown on page, a place holder and a save button on my form.Now, I am creating a textbox on selectedIndexChanged event of dropdown list and adding it to placeholder. And on button click I want to access the control, but on click event, I find the textbox as null. Here is my code
I'm creating an ASP.NET control dynamically based on a value selected in a dropdown; for instance the field can be a textbox or a checkbox (for now), and then it gets added to a placeholder control. However, I'm unsure how to retrieve the value - using the placeholder's FindControl method returns null although I'm specifying the ID when I create the control.
Selecting a value and clicking the button, doing postback, I want to capture the value selected in the ddl. I was using "FindControl method" but it is not working, I guess because the controls are created dynamically and will not show due to stateless HTTP.
I am using ASP: menu in my site.master page ' but when I clicked on any button or drop down from other page the menu is disappeared. Why my menu is disappearing from the site.master page ?
I have a small problem I am returning some data from a query and have allowed paging, however when I click on the next button to view the following page the gridview disappears.
My datasource is specified in the code behind:
<asp:Panel ID="dtpanel" runat="server" Visible="False"> <asp:GridView ID="grddetails" runat="server" AutoGenerateColumns="False" AllowPaging="True" OnPageIndexChanging="grddetails_SelectedIndexChanged" ViewStateMode="Enabled" onselectedindexchanged="grddetails_SelectedIndexChanged" AllowSorting="True" > <Columns> <asp:BoundField DataField="Col1" HeaderText="Col1" SortExpression="Col1" /> <asp:BoundField DataField="Col2" HeaderText="Col2" SortExpression="Col2" /> <asp:BoundField DataField="Col3" HeaderText="Col3" SortExpression="Col3" /> <asp:BoundField DataField="Col4" HeaderText="Col4" SortExpression="Col4" /> <asp:BoundField DataField="Col5" HeaderText="Col5" SortExpression="Col5" /> <asp:BoundField DataField="Col6" HeaderText="Col6" SortExpression="Col6" /> </Columns> </asp:GridView> </asp:Panel> using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; using System.Data; using System.Data.SqlClient; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { } protected void GridView2_SelectedIndexChanged(object sender, GridViewCommandEventArgs e) { int y = Convert.ToInt32(e.CommandArgument); Control control = GridView2.Rows[y].Cells[0].Controls[0]; LinkButton btn = control as LinkButton; string qval = btn.Text; string query = "SELECT * FROM Table WHERE Col LIKE '%" + qval + "%'"; string connectionString = @"Data Source=servername;Initial Catalog=dbname;Integrated Security=True"; SqlConnection accessConnection = new SqlConnection(connectionString); SqlCommand accessCommand = new SqlCommand(query, accessConnection); SqlDataAdapter grddetailsDataAdapter = new SqlDataAdapter(accessCommand); DataTable grddetailsDataTable = new DataTable("Table"); grddetailsDataAdapter.Fill(grddetailsDataTable); int dataTableRowCount = grddetailsDataTable.Rows.Count; if (dataTableRowCount > 0) { grddetails.DataSource = grddetailsDataTable; grddetails.DataBind(); } dtpanel.Visible = true; } protected void GridView1_SelectedIndexChanged(object sender, GridViewCommandEventArgs e) { int w = Convert.ToInt32(e.CommandArgument); Control control = GridView1.Rows[w].Cells[0].Controls[0]; LinkButton btn = control as LinkButton; string qval2 = btn.Text; Label1.Text = btn.Text; string query = "SELECT * FROM Table WHERE Col LIKE '%" + qval2 + "%'"; string connectionString = @"Data Source=servername;Initial Catalog=dbname;Integrated Security=True"; SqlConnection accessConnection = new SqlConnection(connectionString); SqlCommand accessCommand = new SqlCommand(query, accessConnection); SqlDataAdapter grddetailsDataAdapter = new SqlDataAdapter(accessCommand); DataTable grddetailsDataTable = new DataTable("Table"); grddetailsDataAdapter.Fill(grddetailsDataTable); grddetails.DataSource = grddetailsDataTable; grddetails.DataBind(); dtpanel.Visible = true; } protected void grddetails_SelectedIndexChanged(object sender, GridViewPageEventArgs e) { DataTable dataTable = grddetails.DataSource as DataTable; grddetails.PageIndex = e.NewPageIndex; grddetails.DataBind(); dtpanel.Visible = true; } }
I have a ListView that has a FileUpload control and a button in each ListViewItem. I have an OnClick event on my button where i try and pull information from the FileUpload control, but when I try to access the control all of the values that were set are gone (FileName etc).
What do I need to do differently here to access the information I just entered?
How should I go about removing dynamic control.I have a method that does the removing currently, however, it doesn't remove when postback..Here's my code
I have the following problem. I have a user control with its own events and procedures. I added this control to a page programmatically. It appears as it should but when you click a button on the user control. the control disappears from the page.
On my Form I have 2 gridviews namely; gvCRSearch (that displays search results) and gvCRView (that displays all the change requests raised).. Now, when the records are more than 10 in gvCRSearch it automatically creates a navigation number i.e., 1 2 3 Same thing happens to gvCRView
What is wrong is that when I click the navigation i.e., ( for example 2) on gvCRSearch
1) the gvCrSearch becomes visible = false
2) the gvCRView if it has a navigation number is moved to 2
So the effect is seen the next view (gvCRView) and the gridview (gvCRSearch becomes invisible)
I am trying to add an additional column on the gridview. Everything work fine. The problem is, when i add a new button on the page where the gridview exists and hit the button. The added column in gridview went missing. The button do not have any code behind associated with it and I am using VS2008. Anyone know what have cause this and how to solve this problem? I need the added column to be there even user click on the button.
Yesterday (Thursday Sep 10th 2010) I was happy to have a TabContainer working fine on a simple page as im learning to use it.
On the page was:
1) Ajax Script manger. 2) 1 command button (it would make label1.text = "hello world" 3) A Ajax TabContainer with 2 tabs... 4) Label1
That was it and it was working fine in Chrom and IE Woohoo.. I go home...
This morning I load it up to keep working way and doing more with it.... Chrome is my default browser, it loads and I click tab2 then tab 1 all is well.... I click Butto1 and the hole TabContainer disapears..
After much dinging I find it still works in IE but that my Chrome has updated (on its own): (I notice only one ICON in Chrome in the uper right corner by the addres bar... Only the Wrench ICON, No more Page ICON.. So I check and sure enough Chrome did a push to V 6.0.472.55.. Anyhow thats the difference and now TabContainer goes poof/disappears when clicking a button that refeshes the page.
i have a usercontrol inside an updatepanel. when i click some button this usercontrol will be loaded. and the usercontrol itself has anither button in it. the problem is that the usercontrol code behind is never executed and when the button is clicked the usercontrol disappears.
In Visual Studio 2008 ,in my application page 'TEST.aspx' have an 'Ajax TabContainer' inside update panel , and Tab Panel "Product Group Identification" containes textboxes ,DropDownlist and button like 'Save' and 'Cancel' , on clcik of 'save' or 'cancel' buttons only dropdownList Disappears for a second and reappears this is due to Update panel.
I am developing a call center application. The way it works is it read records from a database and from these it creates dynamic questions and either textbox or dropdown controls on one of about 5 tabs. The questions can change depending on the previous answers, thats why they need tgo be dynamic. The issue is the postback will loose the controls I have created. I thought about maybe just keeping a hashtable of the controls in the session and then recreating them each page create. The trouble is the page flicker. what the best way to handle this ??? I've though about update panel manipulation but nothing seems to work the way I need it to.
I have a Placeholder in which I added a Hyperlink (the hyperlink is an attachment in messaging application) how do I get the hyperlink to go hot when the user put there mouse over it:
I've an UpdatePanel where according to operations inside of this UP is filled. I've add some buttons but the buttons to not fire clicks. I've used the code
Button b = new Button(); b.Click += new EventHandler(ClickMe); ... void ClickMe(object sender, EventArgs e);
im creating dynamic buttons on page load and on the click event of button1 handlere iam creating more buttons this is going fine but on click event of button 2 work is not done so how to maintain a chain of creation of button on click events
I have a formview that has several dropdownlists in the EditItemTemplate. Some of the dropdownlists are added using placeholders. I can add and populate their listitems without any problem. But when I update the record, none of the controls can be found--even though when I look at the page source they are there. I first strated out using asp:ControlParameter in my sqldatasource updateparameters, but even referencing the control as myform$mycontrol did nothing. So then I moved to code behind on the sqldatasource.updating event (code is attached). The only controls I cannot seem to bind to the update are those added via the placeholder.
[Code]....
The item at the dim statement is not an item added using a placeholder and does not get a null reference exception (I used that to prove during debbugging that I wasn't losing my mind)--however, all the items being used to get the parameter values are getting null reference exceptions and are added via placeholders. Here is the code I'm using to set up the dropdownlists:
[Code]....
how to get the value of these controls so they can be used in my update?
Dim objDatabase As New database objDatabase.OpenSQLConnection() Dim objAdapter As SqlDataAdapter Dim objDataset As New DataSet Dim objAdapter1 As SqlDataAdapter Dim objDataset1 As New DataSet Dim objAdapter2 As SqlDataAdapter Dim objDataset2 As New DataSet
i am using above code to generate dynamicaly textbox into grid view. I have 3 fix coloumns from database which i fetch at start of code.
Then i assigned it to datatable. in datatable according to Listbox item count i added more coloumn as per listbox items count.
then that datatable i i gave as datasourse to gridview. Now i inserted dynamicaly textbox to gridview in respective coloumn.
But after refreshing page all textboxes disappears....
I have searched around but unable to find a solution that will work. I have a link button that is created dynamically during the page load. It is given an ID (obviously). There is a script manager on the page. I have the controls added to a panel in the updatepanel (updatePanel1). There is a dynamic label that is also created with each link button. I can get a response from the linkbutton click event during a postback on the second time clicking the linkbutton, but I am getting a complete postback instead of the asyncpostback for that control. During the creation of the dynamic linkbuttons, I am also creating a dynamic trigger for each button and adding it to the updatePanel1. The Click event is not firing the method without doing a complete page postback.
I am exporting some data to a PDF and I have been using iTextSharp with a lot of success, but I just hit a wall.
I have a group of information I need to keep on a single page. This information includes a handful of other Paragraph objects and tables. I can add 3 Paragraphs to another parent Paragraph and set that parent's KeepTogether property to true and everything works great.
When I add a PdfPTable to the Paragraph with KeepTogether set to true, the table disappears. No Exceptions or error messages, the table just disappears.
Any clue as to what is happening? Is there a work around? Should I be coding differently, like is there a better parent control than Paragraph to keep text and tables together on one page?
