C# - Find Control Within ContentPlaceholder And Placeholder?
Sep 23, 2010
I am adding controls dynamically to PlaceHolder which within ContentPlaceHolder
var t = (ContentPlaceHolder)Master.FindControl("ContentPlaceHolder1");
var t1 = (PlaceHolder)mpContentPlaceHolder.FindControl("PlaceHolderName");
var t2 = (DropDownList)t1.FindControl("ControlID");
It looks like I am missing something because t2 is always null
I'm using a Master Page with two content areas to render a two-column format.In the left column (Content ID="Left") I have an UpdatePanel (ID="ChoosePanel") with a TreeView control whose ID is "StickTree".In the right column (Content ID="Right") I have another UpdatePanel (ID="ChartPanel") with UpdateMode="Conditional" and the following trigger:
There should be no problem having the trigger in a different UpdatePanel, but I'm getting the following exception when I run the page:A control with ID 'StickTree' could not be found for the trigger in UpdatePanel 'ChartPanel'.
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.
Now, basing on some condition I would like to show/hide a given div. So I am trying to reach one of those divs by Controls collection, like this:
public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { ContentPlaceHolder myContent = (ContentPlaceHolder)this.Master.FindControl("ContentPlaceHolder1"); myContent.FindControl("TestDiv1").Visible = false; //this is not working } } } }
But the above example is not working. None of the two div control exists in the myContent.Controls collection. If I place for example a TextBox on my content page, I can reach it through Controls.
So what should I do to be able to access the div control?
how to maintain state of placeholder. i have a placeholder in which i add many image controls dynamically but when my page get refresh all controls from placeholder gets removed from it. the enableViewstate of placeholder is set to true.
How do i refer a control id from a different ContentPlaceHolder by using inline code?
I have filterParameters which refer a control (txtSearch). Since it was place in different contentplaceholder (ContentPlaceHolder2) , its id could not be find by it name "txtSearch", is there any inline code syntax can help me?
I am writing an ASP.NET custom control.In my custom control code, I find a PlaceHolder control in the page like so:this.myPlaceholder = Page.FindControl("placeholder1") as PlaceHolder Then, I render the placeholder as the output of the custom control:
protected override void Render(HtmlTextWriter output) if (this.myPlaceholder != null) this.myPlaceholder.RenderControl(output);
However, this causes the placeholder to be rendered in two places - in the custom control output (good) and in the original location in the page (bad).
In my default.aspx page I have a PlaceHolder control within an UpdatePanel. In this placeholder control I will dynamically load a web user control, which is just a form with a submit button. On this user control, I have the form within an update panel and I have the "Submit" button's Click Event added to the triggers.
When I submit the form, the UpdatePanel on the web user control nor the update panel on the default.aspx page are capturing the post back, thus causing a full post back which refreshes my page.
how to capture this post so its rendered in Ajax and not a full post back?
I have a asp.net webpage which is using an Master page and contentplaceholder.
My Req: I want to access the control name through javascript.I have tried to use 'document.forms[0].elements[i].name' but its giving an error since my page there is no form.Only master page and contentplaceholder.
I am using list view to display the the data but i am getting an error like An item placeholder must be specified on ListView 'ListView1'. Specify an item placeholder by setting a control's ID property to "itemPlaceholder". The item placeholder control must also specify runat="server.Even i have specified the itemplaceholder id but no use still same error.
I've created a usercontrol in asp.net webforms (c#) called 'Article' which contains a general layout for an article and has a public property called datasource. the datasource will be populated by a subsonic (DAL) activerecord. In the controls pre-render event it will read the record and populates the labels. I think this is a flexible solution with easy maintenance. My problem however is that when I try to add the control to a placeholder all my controls like labels, literals and the like receive a null reference exception. I'm trying to spawn the controls as followed:
foreach (DAL.Article item in coll) { p7.Controls.General.Article.Article article = new p7.Controls.General.Article.Article(); article.datasource = item; phContent.Controls.Add(article); }
Is there something I've completely missed? It's driving me crazy heheh! Another question is do you guys know if this method will have a big impact on performance. I'm only adding 10 of those article controls per page.
It looks to me that the ASP.Net PlaceHolder control doesn't emit any HTML, and therefore can't be used by clientside javascript or JQuery to add items to the PlaceHolder. Does anyone know of a way around this limitation, or of an ASP.Net control that can be used to dynamically add items by client side code?
I'm using a masterpage and having some trouble with my ContentPlaceholders. I have a combobox(DropDownList1) in the sidemenu content placeholder and in my main placeholder I have a gridview. The gridview is supposed to do a select in the db using the selected value of DropDownList1. When I set up the connection SQL within the datagrid, using the wizard; I select to get a parameter from a control and then I select DropDownList1.
Now, When I try to run the page, it returns an error "Exception Details: System.InvalidOperationException: A control with ID 'DropDownList1' could not be found", however if I move DropDownList1 to the main placeholder, everything works perfectly.
How do I get asp.net to see the control sitting in the other placeholder?
Need accessing the rendered content of a PLACEHOLDER control. I dynamically add a web forms page to a placeholder using "TABLE" this works great (cell row table placeholder ) now I wish to take that placeholder and use the rendered page to generate a PDF document.
If it possible to access the rendered code how would this be done?
I am having problems finding my UserControls inside the Controls collection of a Placeholder control.
I have a ListView control with a PlaceHolder control in its ItemTemplate. OnItemdataBound for the ListView control I am adding a custom UserControl to the Controls collection of the Placeholder control. It all renders fine. My problem is when I try to find my user controls in the Placeholder. I just can't get it back. My code is below.
My objective here is to get to the input controls within my UserControl and call the save method of this.
If I have an asp.net web page with placeholders,what is the simplest way to wrap a line break into a control that I can pass to the Add function of the placeholder?