The scenario I'm dealing with is I have a set of entries in a database that have an image associated with them. This image needs to be 'accepted' or 'rejected' via a web interface.
I'm using ASP.NET WebForms.
I'm attempting to databind my recordset of entires to a CheckBoxList control. I would like to combine data from my dataset with information from the web.config file and plain text to display an image:
<asp:CheckBoxList ID="CheckBoxList1" runat="server"
DataSourceID="DataSource1"
DataTextField="ImageIdentifier"
DataValueField="EntryId"
DataTextFormatString="<img src='<%$ AppSettings:GetImageUrl %>{0}' />" />
This approach correctly outputs the plain text and the DataTextField value, however it does not interpret the code inside the <% %> block and prints the whole thing literally in the generated HTML, in spite of it being correctly highlighted in the editor.
Is this possible to achieve declaratively? If not, is there a better way than iterating through the entries in the list in code on the OnDataBound event?
Thanks in advance,
Jamie
I believe you're using the wrong <% tag. In order to evaluate in a binding expression like that it should be <%#
What does your web.config look like? You'll won't be able to use that binding syntax here - you'll have to hook into the databound event of the checkbox and iterate each checkbox, updating them as necessary from the values in your web.config.
EDIT
If you don't want to iterate each checkbox after the checkboxlist has been databound, you'll have to update your dataset first, before you bind to it.
Related
I'm creating an UserControl and I'm passing a variable to it.
It works fine if I do it this way:
<uc:TestControl ID="testControl" runat="server" Variable="test"></uc:TestControl>
However I want to pass a dynamic variable to the control like this:
<uc:TestControl ID="testControl" runat="server" Variable="<%=dynamicVariable%>"></uc:TestControl>
But unfortunately that doesn't work and I know I could assign it on Page_Load but I don't like that way.
So I'm wondering if it's possible at all. Is there any way to assign a dynamic variable to an attribute like I wanted above? Or am I required to do it in Page_Load?
Any feedback would be appreciated!
Thanks!
<%= syntax doesn't work with controls marked as runat="server" .Try using the databind syntax
Variable="<%#dynamicVariable%>"
Then calling databind on the user control as per this SO question
EDIT
To database i think it's a straight
testControl.DataBind()
supported in ASP.Net 3.5 and greater.
I have a multiline (> 50 lines) textbox containing plain text. I want to add either a session variable to the text in this box. In asp I would have done it by putting in <% %> code blocks but in .net I am getting the following error: "Code blocks are not supported in this context". I assume therefore that this would need doing in code behind.
Is there a quicker way than putting all the text from the textbox in a string in code-behind and then adding the variable on like this? I would like to keep the text in my aspx page if possible.
Thanks
How about your codebehind does something like:
myTextbox.Text += Session ["mySessionVariable"];
after you've filled the textbox.
Incidentally, you don't have to
'put all the text from the textbox in
a string in codebehind'
as the .Net framework exposes all the front-end controls as codebehind objects automatically.
EDIT:
<asp:TextBox ID="TextBox1" runat="server" Rows="15" TextMode="MultiLine" Columns="70" Text='<%# Session["var1"] %>'></asp:TextBox>
This will work for binding just the session variable to the control. Don't forget to call
Page.DataBind();
after you've set your Session variables. Probably in Page_Load.
This will allow the binding such as it is, to occur. This won't work if you want to mix up static markup text with dynamic variables. For that, you'll need to get busy in the code-behind.
HTH.
Have you tried <%=Session["MySessionKey"] %> ?
I'm a newbie in asp.net.
When using FormView, there is a big amount of code in ItemTemplate, EditItemTemplate and InsertItemTemplate which is almost identical.
For example:
<asp:ListBox ID="ListBox2" runat="server" Rows="1" CssClass="field"
DataSourceID="StatusList" DataTextField="DESCRIPTION"
DataValueField="STAT_ID" SelectedValue='<%# Bind("STAT_ID") %>'>
</asp:ListBox>
(Note: at the exception that Eval() would be used instead of Bind() in ItemTemplate)
I've been trying to avoid repeating this code but without the expecting result:
ListView allows the use of LayoutTemplate - but I didn't see any examples that insert this kind of code in LayoutTemplate. And inserting this code in LayoutTemplate would result in an error.
DetailView allows to produce code automatically but I'd like to use a specific design (for ex. using "fieldset" that encompasses some fields).
What would be the best way to avoid repeating this kind of code ?
You don't have to much choice about seperately specifying the Bind/Eval part, but you do have some control over the other pieces. You can make a custom UserControl that contains your layout.
Usually I include a property on this usercontrol called "Mode" which I either set to Edit or View, then based off of this property I change enabled/visible properties on the controls. You'll also need to include a property for each value you want bound/displayed in the usercontrol.
Put some labels, textboxes, etc... in your designer and hook them up to properties in your code behind, put the usercontrol on your page in your item/edit template and eval/bind to your data to the various properties (make sure to set the mode so it displays right).
Looking for a custom ASP .NET control were the InnerHTML of a DIV is connected to a databas to fetch the content to render the HTML content from the databas inside the DIV.
Is there one out there I have missed or anyone could tell if its possible to make my own DIV component to make it DataBound?
Thanks,
Stefan
You can't databind to a div, but you can databind to something like a Repeater, which is mainly good for showing rows of data (i.e. repeating the same markup for multiple data items).
If you just want to show one field from one row, you're probably better off with something like a literal:
<div>
<asp:Literal id="myLiteral" runat="server" />
</div>
And then in the code behind...
myLiteral.Text = "some string from the database or wherever";
I have a Repeater which displays a list of items (in a grid-like/table view). When a user clicks an item, I display an UpdatePanel under this item with additional information relevant to the item (similar to Accordion control). I know how to populate the elements of the UpdatePanel in code-behind (I pass the ID of the selected element in the Repeater control as CommandArgument, get additional info for this ID, and set up the text fields of the active UpdatePanel controls). But I'm wondering if I could set up binding directly in the ASPX (instead of code-behind). When I used the <%= %> syntax to assign text fields of the UpdatePanel control the values of the page properties, e.g. <%= Comment %>, it sort of worked, but it changed the fields of all UpdatePanels in the repeater. Is there any way to bind the active UpdatePanel to the current values and leave already bound UpdatePanels unchanged?
Are you looking to display a container that displays additional information? Is there other activity in the "box" that requires it be an updatepanel?
<asp:repeater>
<itemtemplate>
<%# Eval("Name") %> <%# Eval("LastName") %><br />
<span onclick="$get('<%# Eval("Id") %>')">View Age</span>
<div id="<%# Eval("Id")%>" style="display:none;">
Age: <%# Eval("Age") %>
</div>
<itemtemplate>
</asp:repeater>
Ithink that's right, some syntax may be off a bit (typing without intellisense). Would that work?
I used ID as a unique identifier for the div id and the onclick command. You could also use jquery, asp:controls or whatever else you wanted.
Easiest way is to nest a FormView inside the update panel. Then the only thing you need to do in the code behind is get the additional info, assign it to the FormView.DataSource, and call FormView.DataBind(). Everything in the FormView will use the <%# Eval("SomeColumn") %> syntax. You'll probably need to use a FindControl() to get a reference to the FormView. I'd type up the code for you but I'll save you some headaches down the road and say DON'T DO THIS.
The update panel is about the most inefficient way to do any ajax stuff. The only way to get it all to wire up correctly with this repeater and server side code is to either have a gigantic viewstate or to rebind the repeater in your page load. You are turning a request that could be 300ms into something that will take over a second...or longer! Get familiar with a good ajax framework and don't be afraid to write real html. At the very least, use a webservice that loads a usercontrol with your markup.
I know the update panel is easy, and it's built in. It might even be adequate for what you are doing, but you must resist. You'll be glad you did.