This is the page code for the control:
<asp:TextBox id="someID" maxlength="10" columns="10" runat="server" Text="<%# work %>" />
This is how I set up and populate the variable before page is rendered, it is in the code behind, I have tried I think all the variations available for the variable declaration, e.g. public, shared, protected, etc.:
Public work As String
work = "987654321"
The textbox always comes up blank. referred to this ms kb page for how this work and it has a specific example.
However, it didn't explain anywhere if there is some special way of declaring the variables used in the binding or some special way to set the value of the variable, or is there something needed to allow the <%# syntax to work?
Binding doesn't happen automatically. You have to call DataBind() either from Page control or the text control. Try put it in Page_Load() method.
Related
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).
I'm trying to perform two-way data binding on the controls in my user control, which is hosted inside a FormView template:
<asp:ObjectDataSource runat="server" ID="ObjectDataSource"
TypeName="WebApplication1.Data" SelectMethod="GetItem" UpdateMethod="UpdateItem">
</asp:ObjectDataSource>
<asp:FormView runat="server" ID="FormView" DataSourceID="ObjectDataSource">
<ItemTemplate>
<uc:WebUserControl1 runat="server"></uc:WebUserControl1>
</ItemTemplate>
<EditItemTemplate>
<uc:WebUserControl1 runat="server"></uc:WebUserControl1>
</EditItemTemplate>
</asp:FormView>
The web user control:
<%# Control Language="C#" ... %>
<asp:TextBox runat="server" ID="TitleTextBox" Text='<%# Bind("Title") %>'>
</asp:TextBox>
The binding works fine when the FormView is in View mode but when I switch to Edit mode, upon calling UpdateItem on the FormView, the bindings are lost. I know this because the FormView tries to call an update method on the ObjectDataSource that does not have an argument called 'Title'.
I tried to solve this by implementing IBindableTemplate to load the controls that are inside my user control, directly into the templates (as if I had entered them declaratively). However, when calling UpdateItem in edit mode, the container that gets passed into the ExtractValues method of the template, does not contain the TextBox anymore. It did in view mode!
I have found some questions on SO that relate to this problem but they are rather dated and they don't provide any answers that helped me solve this problem.
How do you think I could solve this problem? It seems to be such a simple requirement but apparently it's anything but that...
My current workaround for this is, although rather cumbersome, to subclass the FormView class and use subclassed controls in it, implementing my own data binding logic (taking the data field name from a new property) instead of using the <%# %> syntax. Apparently, the code the latter generates is the real culprit here as it doesn't support this nested control scenario.
I ended up, using old asp include statement
<--%include file = "filename" -->
instead of using user controls for dealing with the code duplication issue.
I have an asp:button control and am using the "CommandName" and "CommandArgument" parameters in the .aspx file. The CommandName is found with <%# Eval("Name") %>, but the CommandArgument has to be found via a javascript function. However, I'm not quite sure how to do this inline. The function returns a number (integer), which is to be used as the value of the CommandArgument. Is it possible to do this?
Thanks
EDITED TO ADD CODE
I've added an example code (don't have access to the real code atm). However, basically, the CommandArgument should be the value returned by the function CalculateLength().
function CalculateLength(a,b) {
return a*b;
}
<asp:Button ID="btnUpdate" runat="server" Text="Update" CommandName=<%# Eval("Name") %> CommandArgument= ??? //Should be result of CalculateLength(a,b).
I am not sure how you are going to get the javascript to work because the aspx code is running server side and building the output for your button. By the time the javascript runs the page code has already been built and the button's html and attached javascript as well.
Is there anyway to calculate the function server side and then just do:
CommandArgument="<%= CalculateLengthServerSide() %>"
You don't need to just use the data your binding to, you can call any server side function.
Edit: Try switching your label that stores the quantity to a textbox and making it read only so uses will not mess with it. After the button is clicked, you should be able to find the textbox control and read out the posted value.
I'm a bit new to .Net development, been working in Java for some time now. I have an aspx page and we need to externalize some strings to make it more flexible.
If I have a table somewhere and there is just a string sitting outside an asp tag, I can replace it so that
<th> Specific Foo String </th>
becomes
<th> <%= Strings.foo %> </th>
and everything is fine, the problem I'm running into is how do you do this kind of interpolation on an asp tag property
I tried changing
<asp:Label runat="server" ID="lblFoo" Text="Specific Foo String Entry" />
to
<asp:Label runat="server" ID="lblFoo" Text='<%= Strings.foo %> Entry' />
and
<asp:Label runat="server" ID="lblFoo" Text='<%#Eval("Strings.foo") %> Entry' />
but neither worked. Is what I'm doing not possible in the aspx file, I know that I can simulate this by rewriting their properties in the code behind, but that's a level of overhead I'd rather not deal with.
Thanks
I think you are looking to do this:
<asp:Label runat="server" id="label1" Text='<%# Strings.Foo + " Entry"%>' />
Then in your code behind (most likely in your OnPageLoad) you need to call
if(!Page.IsPostBack) Page.DataBind();
You need to be cautious however as calling DataBind on controls like textboxes or any labels that may have changed due to logic in the code behind will have their values overwritten with the bound values. Checking that you are not on a post back can help with this, but there are still gotchas.
Also note that I had to move the " Entry" text into the binding statement. If it is placed outside the last '%>' then the binding does not work and it will spit out:
<%# Strings.foo %> Entry
In the codebehind of the page you would do this:
lblFoo.Text = Strings.foo + " Entry";
A good place to put this code would be in the overriden OnLoad method but that is simply a suggestion as I am unfamiliar with your application and the life cycle needs of your page.
If you want to do all this in the aspx page then simply do this:
<span><%= Strings.foo %> Entry</span>
as a Label renders as a span anyhow.
If your objective is an HTML table of strings, then you can create either a ListView or a GridView and DataBind to that. It would save you the trouble of writing out all of your properties and will also produce the correct table tags for the data.
Without knowing more about your data, I cannot provide a detailed code snippet.
You're talking about resources. Read Basic Instincts Resources and Localization in ASP.NET 2.0 which shows you the built in resource editor, and how to use the "<%$ ... %>"-binding, or using meta:resourceKey attribute.