Using asp.net in html pages - c#

If I want to combine asp.net code with html (mark up) file, I need to open <% %> and execute teh code.
What If I want to iterate over a database with select query while feeding information and creating rows. For example:
<table>
<%
foreach(DataRow dr in dataset.Tables["empoloyees"].Rows)
{
%>
<tr>
<td>
<asp:Label runat="Server" Text="<% dr[FirstName].toString(); %>"/>
</td>
<td>
<asp:Label runat="Server" Text="<%dr[LastName].toString();%>"/>
</td>
</tr>
<%
}
%>
</table>
Is the syntax correct..and is that practice good (it is always used in php) ? or should I bind the data to the label somehow?(no idea how. but somehow)?

If you're trying to take a set of data and display it in a table then try using control like the GridView or the Repeater.

First and most important thing - do not mix business logic and data access functionality with the data representation markup!
Supposing you are using WebForms, you can use Repeater control which is bound in the code behind of a page/control (aspx.cs/ascx.cs) so View stay decoupled and just bound to specific properties of data source:
ASPX:
<asp:Repeater ID="employees" runat="server">
<HeaderTemplate>
<table>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td>
<asp:Label runat="Server"
Text="<%# DataBinder.Eval(Container.DataItem, "FirstName") %>"/>
</td>
<td>
<asp:Label runat="Server"
Text="<%# DataBinder.Eval(Container.DataItem, "LastName") %>"/>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>
Code Behind: (Page_Load() for instance)
employees.DataSource = dataset.Tables["empoloyees"].Rows;
employees.DataBind();

I suggest using a Repeater control if you want a piece of markup to iterate over and bind to it.
<asp:Repeater id="Repeater1" runat="server">
<ItemTemplate>
<tr>
<td> <%# DataBinder.Eval(Container.DataItem, "FirstName") %> </td>
<td> <%# DataBinder.Eval(Container.DataItem, "LastName") %> </td>
</tr>
</ItemTemplate>
</asp:Repeater>
Alternatively, use a GridView, though I find that Repeater gives you more control over the emitted markup.

You are almost there. Try this:
<table>
<%
foreach(DataRow dr in dataset.Tables["empoloyees"].Rows)
{
%>
<tr>
<td>
<%= dr[FirstName].toString(); %>
</td>
<td>
<%= dr[LastName].toString();%>
</td>
</tr>
<%
}
%>
</table>

You should use a repeater instead something like this
<table>
<asp:Repeater runat="server" ID="userRepeater" >
<ItemTemplate>
<tr>
<td><%#DataBinder.Eval(Container.DataItem,"FirstName")%></td>
<td><%#DataBinder.Eval(Container.DataItem,"LastName")%></td>
</tr>
</ItemTemplate>
</asp:Repeater>
</table>
and in your codebehind
userRepeater.DataSource = dataset.Tables["empoloyees"];
userRepeater.DataBind();
for a list of all types of <% %> take a look here

You don't have to use <% %> at all. Just put your code in between tags with runat="server", and then go ahead and use standard ASP.NET tags (e.g. asp:TextBox runat="server"). Just make sure it's an *.aspx page.
FWIW, your question seems a little backwards to me. If you are creating *.aspx pages then you can just use standard HTML anywhere you want. If you are trying to somehow squish ASP.NET into an *.html page - then you are misunderstanding how ASP.NET works.

Related

Error in table when adding runat=server

I have a html table in my ASPX page and would like to use it in code-behind for some processing. The table is shown as below:
<table class="hovertable" id="tblData">
<tr>
<th>ID:</th>
<td colspan="3" style="font-weight: bold">
<%= Eval("ID") %>
</td>
</tr>
<tr>
<th>Date:</th>
<td><%# Eval("Date", "{0:dd-MMM-yyyy}") %></td>
<th>Amount:</th>
<td><%# Eval("Amount", "{0:C}") %>
</tr>
</table>
However, when I add the runat="server" attribute to my table, I am produced with the following error:
CS1502: The best overloaded method match for 'System.Web.UI.HtmlControls.HtmlTableRowCollection.Add(System.Web.UI.HtmlControls.HtmlTableRow)' has some invalid arguments
Any ideas what may be wrong here? Am I missing out anything?
An html table (which is not a pure asp.net server control) can't contain asp.net server controls. Take a look at this answer:
http://forums.asp.net/t/1524580.aspx/1
In my opinion, you should ask yourself the following question?
Do i need to solve this client or server side?
if your answer is client, you should implement the update logic with Ajax, otherwise you could use the ASP.NET server control and implement it server side.
OK guys, I have solved this issue by myself. The problem causing it was because of a <td> not having the corresponding <tr> element.
It was something like below:
<table class="hovertable" id="tblData">
<tr>
<th>ID:</th>
<td colspan="3" style="font-weight: bold">
<%= Eval("ID") %>
</td>
</tr>
<tr>
<th>Date:</th>
<td><%# Eval("Date", "{0:dd-MMM-yyyy}") %></td>
<th>Amount:</th>
<td><%# Eval("Amount", "{0:C}") %>
</tr>
<td colspan='4'>
Some data....
</td>
</table>
I think you can use this for the same purpose
<asp:Table ID="Table1" runat="server">
</asp:Table>
What you are trying to do is adding runat="server" attribute to a HTML control
Try adding <asp:Labels> where you need to manipulate data.
<table>
<tr><td><asp:Label id="lblRow" runat="server" /></td></tr>
</table>
Table columns and rows cannot be accessed via code behind if you have runat="server" in the tag because they are pure html.
Another way is to use a StringBuilder to create the html table in the code-behind and and asp:LiteralControl to output the table.
Also if we remove the tbody element it will not throw error for td mismatch
Nikhil Mittal
Remove the below elements
<thead>
</thead>
<tbody>
</tbody>

Insert data into asp.net table through code

I have a table in asp.net page and i want to insert the data which will be recieved from service call through c# code behind. Any idea on how to do this.
Below is my table.
<table id="DataTable" class="style1">
<tr>
<td>
</td>
<td>
</td>
<td>
</td>
<td>
</td>
</tr>
</table>
I just need to insert values recieved from service call in place of &nbsp.
In your aspx page asp:Label controls and assign the values from code behind by accessing them using Id.
Inside .aspx
<asp:Label Id="lblName" runat="server">
In code behind
lblName.Text = "Value from Service";
If you need to repeat this table use GridView.
Use the asp:Table control instead.. It gives you much more control from server side than a normal html tag :)
And it ofc render as a normal table client side
If you persist on working with pure html table you can use an new/old style to control it.
like so:
<table>
<% foreach ( var o in objects ) { %>
<!--UserControl -->
<tr>
<td> can put here data like so: <%= o.Id %> </td>
</tr>
<!--UserControl -->
<%}%>
</table>
or you can use Repeater and Bind data if it's dynamic.
If data is not dynamic and your table will not grow or change size, you can use a little OOP for this.
like so:
create in your class properties and then populate them.
public string MyLabel { get; set; }
put something in page load.
in aspx do it like so..
<table>
<tr>
<td> <%= MyLabel %> </td>
</tr>
</table>
or
<table>
<tr>
<td> <asp:Label ID=|"myText" runat="server"/> </td>
</tr>
</table>
Make the table Html server side control. Try this:
<table runat="server" id="DataTable" class="style1">
<tr>
<td id="td1" runat="server">
</td>
<td id="td2" runat="server">
</td>
<td id="td3" runat="server">
</td>
<td id="td4" runat="server">
</td>
</tr>
Now in the code behind
td1.InnerText="xx" or td1.InnerHtml=..

How do I make a repeater with no datasource function until it gets one from a postback?

I have a repeater on my page which I use to display a list of search results. My issue is that the page keeps throwing me a
Parser Error Message: The server tag is not well formed.
error because the repeater has no datasource
Repeater:
<asp:Repeater runat="server" ID="rptSearchResults" >
<HeaderTemplate>
<h3>Search results</h3>
</HeaderTemplate>
<ItemTemplate>
<table>
<tr>
<td>
<asp:Label runat="server" ID="lblTitle" Text="<%# Eval("title")%>"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label runat="server" ID="lblAdress" Text="<%# Eval("adress")%>"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label runat="server" ID="lblZipcode" Text="<%# Eval("zipcode")%>"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label runat="server" ID="lblCity" Text="<%# Eval("city")%>"></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label runat="server" ID="lblType" Text="<%# Eval("type")%>"></asp:Label>
</td>
</tr>
</table>
</ItemTemplate>
</asp:Repeater>
Above this repeater is a form where users can type in search words for primarily title, adress, zipcode, city and type. The repeater isn't supposed to fill out untill the user clicks the button which triggers the search and thus adds a datasource to the repeater.
Is there a way to make it work like I want it to?
I don't think the lack of a data source is the problem - it should be fine. The error says "The server tag is not well formed." - this means there's a problem with the markup. A problem with an empty data source would cause a NullReferenceException or something similar. So, maybe the problem is your Label elements - try changing the Text attributes from this:
Text="<%# Eval("type")%>"
to this:
Text='<%# Eval("type")%>'
I think all the double quotes will confuse ASP.Net. Use a combination of single and double quotes.
What happens if you disable the repeater control by default? Does it still throw the exception?
If disabling it doesn't work I'd add it dynamically as and when you need it. So that you can keep your template you can strip it out to a user control so you only have to add the user control through code and not the entire item template.

If statement inside a ListView with Eval() or DataBinder.Eval()?

I have a listview control on an .aspx page. Inside this list view i want to check "Type" property which comes from database. here is the example code :
<ItemTemplate>
<%# if(Convert.ToInt32(DataBinder.Eval(Container.DataItem,"Type")) == 0){ %>
<tr class="item">
<td>
<%# Convert.ToDateTime(Eval("WorkDate")).ToShortDateString() %>
</td>
<td style="text-align: center;">
<%# Eval("SkillName") %>
</td>
</tr>
<%# } else if (Convert.ToInt32(DataBinder.Eval(Container.DataItem,"Type")) == 1) {%>
<tr class="item">
<td colspan="2">
<strong><%# Convert.ToDateTime(Eval("WorkDate")).ToShortDateString() %></strong>
</td>
</tr>
<% } %>
</ItemTemplate>
As a last resort i tried to user DataBinder.Eval() but i get the exception "Expected class, delegate, enum, interface, or struct". What can i be doing wrong? Writing a function in code-behind isn't an option for me. Is there a way to achieve this?
Here is the full code, made fancy and short.
<ItemTemplate>
<tr class="item">
<td colspan="<%# Eval(Container.DataItem,"Type")) == 0 ? 1:2%>">
<strong><%# Convert.ToDateTime(Eval("WorkDate")).ToShortDateString() %></strong>
</td>
<td style="text-align: center;" visible="<%# Eval(Container.DataItem,"Type")) == 1>">
<%# Eval("SkillName") %>
</td>
</tr>
</ItemTemplate>
Untested, as I don't have Visual Studio available at the moment, but since HtmlTableRow has a Visible property, the following should work:
<tr class="item" runat="server" Visible='<%# Convert.ToInt32(Eval("Type")) == 0 %>'>
...
</tr>
yes you will have to do some client side scripting though... I would suggest jquery..
you would basically loop through all of the rows in jquery and based on the data in the row you would be able to change the innerhtml of the row object based on the ".item" selector to determine whether it should be in one format or the other.

How to set image Tag URLs programmatically inside of an ASP.NET ListView Control?

I know how you can set an tag's url attribute programmatically in c#, but it seems when I try to access the image element inside of a tag I cannot access it.
The is residing in the <AlternatingItemTemplate>.
NOTE: I am only having this issue inside the <AlternatingItemTemplate>
Now the ListView tag is also databound.(this is probably why I cannot access, because it isn't guaranteed that it will even exist perhaps).
How can I get around this so that I can display my images programmatically or is there a better solution?
Here's the source:
<asp:ListView ID="ListView_Comments" runat="server"
DataKeyNames="ReviewID,ProductID,Rating" DataSourceID="EDS_CommentsList">
<ItemTemplate>
<tr style="background-color:#EDECB3;color: #000000;"> <td><%# Eval("CustomerName") %></td>
<td> <img src='Styles/Images/ReviewRating_d<%# Eval("Rating") %>.gif' alt="">
<br />
</td>
<td> <%# Eval("Comments") %>
</td>
</tr>
</ItemTemplate>
<AlternatingItemTemplate>
<tr style="background-color:#F8F8F8;"> <td><%# Eval("CustomerName") %></td>
<td>
<img id="rateImage" src="" alt="" runat="server" />
......
Should be able to access it in the codebehind in the OnItemDatabound Event. There u can check to see if its an alternating item or not then use FindControl and u should have access to it.
Or, if your image is stored in your datasource y not just set the src using <%# Eval %>

Categories

Resources