I have added placeholder to a page as below.
<tr >
<td >
<asp:PlaceHolder ID="phMemberName" runat="server" >
</asp:PlaceHolder>
</td>
<td>
<asp:PlaceHolder ID="phMemberTextboxes" runat="server">
</asp:PlaceHolder>
</td>
</tr>
I am adding controls(checkboxes) to it dynamically to it.
It works fine but it throws an error if run in debug mode.
What is the reason ?
The error is
The name 'phMemberName' does not exist in the current context
The problem can be solved the issue using FindControl()
like ,
PlaceHolder phMName = (PlaceHolder)form1.FindControl("ControlID");
check this
Is it possible you've made a typo?
"The name 'placeholderName' does not exist in the current context"
Should that not be "phMemberName"
You might be missing the aspx.designer.cs file. Since this file essentially glues the aspx markup controls to the CodeBehind page(aspx.cs), absence of this file can cause the CodeBehind page to not understand where the "placeholderName" placeholder control exists and hence the error "does not exist in current context".
Related
I am working on an ASP.NET VB.NET Web Application. I inherited a bunch of forms from another application we have in house. I'm running into a very strange problem when working on the Login page.
This is an abbreviated version of my code:
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="Server">
<table>
<tr>
<td>
<span id="Span1" runat="Server" style="Color: Red"></span>
</td>
</tr>
<tr>
<td>
<asp:Login ID="Login1" runat="server">
<LayoutTemplate>
<table>
<tr>
<td>
<span id="Span1" runat="Server" style="Color: Red"></span>
</td>
</tr>
</table>
</LayoutTemplate>
</asp:login>
</td>
</tr>
</table>
</asp:Content>
I have a <span id="span1"> that is located inside my web form, within the Content part of the page. I can easily access this in my CodeBehind, and do whatever I want to do with it. However, if i move that span and put it inside the <asp:login> part of the page, it doesn't seem to recognize it, it won't let me access it in code behind, it gives me a squiggly blue line and says
span1 is not declared. It may inaccessible due to protection level
This bit is from the top of the webform in designer
<%# Page Language="VB" AutoEventWireup="false" CodeFile="Login.aspx.vb" Inherits="_Default" MasterPageFile="~/Site.master" %>
This bit is from the Login.aspx.vb page
Partial Class _Default
Just to say it again, id="span1" works perfectly fine where it is shown in the code above, but when I move it inside the I cannot reference it anymore. Since I'm talking about this issue, for that matter I cannot add any new controls inside because I am not able to reference any other controls in vb.net. (this form was pretty much copied from another project, everything works properly I'm just not sure why I'm having this strange issue)
I noticed that a lot of people have similar issues, but in my case I'm working with <asp:login> and I'm really not sure how it's affecting my controls.
EDIT: <span id="Span1" runat="Server" style="Color: Red"></span>
You need to use FindControl on the Login1 Control
HtmlGenericControl hgc = Login1.FindControl("Span1") as HtmlGenericControl;
hgc.InnerText = "Span Found";
VB
Dim hgc As HtmlGenericControl = CType(Login1.FindControl("Span1"),HtmlGenericControl)
hgc.InnerText = "Span Found"
As per my comments, and as requested by the OP...
You're hitting a problem with the naming container.
When the <span runat="server"> is outside of the <asp:Login><LayoutTemplate> it exists as an object within the page, which you can reference directly.
As soon as it's moved within that <LayoutTemplate> it becomes a child of the <asp:Login> control instead.
So to access the control, you can use the following...
CType(Logon1.FindControl("span1"), HtmlGenericControl).InnerHtml = "hello"
The FindControl will bring back an object, but it needs to be "boxed" into the correct type before you can access the InnerHtml property
to access a control on server side, you must include the "runat='server'" attribute on a tag. That's what tells .NET that any given control is supposed to be worked with on the server side as well as the front-end.
Do note that it will change the ID produced in the rendered HTML
<span id="span1" runat="server"></span>
I have a Web Content Form containing a Div and various Server controls like DropDownList. When I run the application, it runs well without any errors, but when I view the HTML source, the Server controls are red underlined. On bringing the mouse over, say, DropDownList, a tooltip warning is displayed:
DropDownList is not a known element. This can occur if there is a compilation error in a website.
Edited
<%# Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="contentReportSchemesMenu.aspx.cs" Inherits="contentReportMenu" Title="Reports Menu" %>
<asp:Content ID="ContentReportMenu" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<div id="divMenu" class="divMenu" runat="server">
<table id="tblMenuLayout" class="Options" runat="server">
<tr>
<td colspan="2" class="Top">Scheme Reports Menu</td>
<td></td>
</tr>
<tr>
<td class="Left">Report Type</td>
<td class="Right">
<asp:DropDownList ID="ddlReportType" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlReportType_SelectedIndexChanged"></asp:DropDownList>
</td>
</tr>
<tr>
<td class="Left">Select District</td>
<td class="Right">
<asp:DropDownList ID="ddlDistrict" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlDistrict_SelectedIndexChanged" Enabled="False"></asp:DropDownList>
</td>
</tr>
<tr>
<td class="Left">Select Block</td>
<td class="Right">
<asp:DropDownList ID="ddlBlock" runat="server" AutoPostBack="true" Enabled="False" OnSelectedIndexChanged="ddlBlock_SelectedIndexChanged"></asp:DropDownList>
</td>
</tr>
<tr>
<td colspan="2" style="text-align:center">
<asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_Click" Enabled="False" />
</td>
<td></td>
</tr>
</table>
</div>
</asp:Content>
A quick Google search soon found the solution: Delete the files from “C:\Documents and Settings[Username]\Application Data\Microsoft\VisualStudio\9.0\ReflectedSchemas” folder (or “…\VisualStudio\8.0\…” if running Visual Studio 2005) in Windows XP. In Windows 7 it is under "C:\Users{User Profile}\AppData\Roaming\Microsoft...etc". Remember also the "VisualStudio" part of the path will be different depending on the version installed.
I closed Visual Studio (always a good ideas for changes that will affect the IDE), deleted the files then re-opened the project. The warnings were gone.
I found references to this solution at:
http://forums.asp.net/t/1205528.aspx
http://blogs.msdn.com/mikhailarkhipov/archive/2005/04/21/410557.aspx
FYI, the search term I used in Google was “element is not supported”.
I don't know why this happens but I do know there are some flakey domain profile things happening in the network environmnet.
You're receiving this error because the table is running at the server, but the tr and td elements are not. When you specify runat="server" on a table element, it expects child elements to run at the server as well.
There are two easy ways to verify this:
Remove runat="server" from the table declaration;
Take the DropDownList(s) outside of the table
Try one of these two options, and see if it fixes the problem.
EDIT
Make sure that the ContentPlaceHolderID on the content form matches the ID of the corresponding content area in the master page. If that doesn't fix your problem, try creating a new content form, applying the advice above, and add a control to the form in the content area. If there are no errors, then you know the issue is somewhere in your markup.
Try deleting the schema cache. To do this, close Visual Studio and delete all of the files in the following directory:
C:\Users\USERNAME\AppData\Roaming\Microsoft\VisualStudio\10.0\ReflectedSchemas
Once the files have been deleted, open Visual Studio again and the problem should be fixed.
You said that "when I view the HTML source, the Server controls are red underlined", but HTML source can not contains such elements like DropDownList because this is the ASP.NET control which is generated as HTML Select tag. Considering that common solution with schema cleanup is not helped you perhaps a problem is in an other place... I'll try to assume that you are opening ASPX/ASCX file itself using some third party editor which is not aware of ASP.NET controls, am I right?
We have a standard asp.net web application and have used asp:PlaceHolders in multiple places. In some files we get this error message during runtime:
BC30311: Value of type 'System.Web.UI.WebControls.PlaceHolder' cannot
be converted to 'System.Web.UI.HtmlControls.HtmlTableRow'.
Why?
If I remove the place holder the page renders just fine.
Here is the html (simplified version):
<table runat="server" id="tblExtradata" visible=true>
<asp:PlaceHolder ID="test" runat="server" Visible="true">
<tr>
<td>
<asp:Label ID="lblExpenses" runat="server" Text="Expensesr"></asp:Label>
</td>
</tr>
</asp:PlaceHolder>
</table>
Version Information: Microsoft .NET Framework Version:2.0.50727.5446; ASP.NET Version:2.0.50727.5420
Because you're running the table at the server, it expects only table elements nested within. If you take the runat="server out of the table, it should work fine.
I have an <asp:ListView> but for some reason the LayoutTemplate section does not show when the list is empty, although the <EmptyDataTemplate> section shows. The LayoutTemplate contains the headers for the table, and I want to show an empty table when there are no items in the datasource, not just the content of EmptyDataTemplate.
If there is no choice I will copy the LayoutTemplate into EmptyDataTemplate but it seems stupid to have to do this. Ideas?
From the MSDN:
The empty template is displayed in a
ListView control when the data source
that is bound to the control does not
contain any records and the
InsertItemPosition property is set to
InsertItemPosition.None. The template
is rendered instead of the
LayoutTemplate template. If the
InsertItemPosition property is set to
a value other than
InsertItemPosition.None, the
EmptyDataTemplate template is not
rendered.
the key words here are "...the template is rendered instead of the LayoutTemplate template..."
So I think, you have to copy the LayoutTemplate into the EmptyDataTemplate template.
In a very simple way you can get both your headers and a message saying that there were no data.
You make your LayoutTemplate like the following idea:
<LayoutTemplate>
<table>
<tr>
<td>a header</td>
<td>another header</td>
<td>third header</td>
</tr>
<tr runat="server" id="itemPlaceholder">
<td colspan="3"
There is no data!
</td>
</tr>
</table>
</LayoutTemplate>
Notice that the tr that is the placeholder (marked by id="itemPlaceholder") actually contains something. It contains what should be shown when there is no data. Then, in code behind, you set the <EmptyTemplate> to be equal to the <LayoutTemplate> (so that you have only one such template to maintain). I do it like this:
Private Sub lvwThings_Init(sender As Object, e As EventArgs) Handles lvwThings.Init
lvwThings.EmptyDataTemplate = lvwThings.LayoutTemplate
End Sub
The logic then is as follows:
When there is data, i.e. when the actual <LayoutTemplate> is used, the whole <tr runat="server" id="itemPlaceholder">, with the td and text it contains, will be replaced by the <ItemTemplate>.
But, when there is no data, i.e. when the <EmptyTemplate> is used (instead of the <LayoutTemplate>), nothing inside the <EmptyTemplate>is replaced, so everything is shown as it is.
You can also put your into a User Control (.acsx). Then include it in the layout template and the empty template... and it will feel less stupid since you can still manage it in one spot. I know how you feel about copying the same code...seems like something a 5th grader would do. Using a control is a more grown up approach.
I just solved this problem when you have InsertItemTemplate with EmptyDataTemplate.
Arrcording to MS docs, that's you can't have both. So I decided to create new tag in InsertItemTemplate.
You can preview my example code here.
<InsertItemTemplate>
<% if (CheckEmptyTable())
{ %>
<tr>
<td colspan="6">No data founds。</td>
</tr>
<% } %>
// Your insert template input here
<tr style="">
</tr>
</InsertItemTemplate>
My result image:
I have the following piece of code:
<asp:Content id="Content1" runat="server" contentplaceholderid="PlaceHolderPageDescription">
<table class="custom-table">
<asp:Repeater ID="oRepeater" runat="server" >
<ItemTemplate>
<tr onclick="javascript:location.href='/nuovoTema/viewIdea.aspx?ID='">
<td><%# ((SPListItem)Container.DataItem)["ID"] %></td>
</tr>
</ItemTemplate>
</asp:Repeater>
</table>
</asp:Content>
The compiler complains that In content pages, content is not allowed outside <script> or <asp:Content> regions.
How can I use asp:Content and asp:Repeater together? I have a list to display.
Thanks
Doesn't look like the error is in the part of the page that you posted. Typically this pops up when you either attempt to place content outside of an asp:content block while in a web content page, or b) have some sort of markup error - lack of a closing tag or similiar - that makes the parser think that you're placing code outside of a content block.
Check your tags to make sure everything that needs to be closed is, in fact, closed. A good way to start is to simply delete everything inside of the content block - well, copy it somewhere - and see if the page still complains. (You'll probably get errors in the code behind).