I have a big problem...I have made a page has a Data FormView controland the insert template of this Formview control has DropDownList to allow the user to choose section (SectionsDDList)..and there's also another DropDownList allow the user to choose a teacher (TeachersDDList)...more infothe SectionsDDList get the section list from SqlDataSource control which the "Select Command" of is:"SELECT section_id,section_id FROM sections"the TeachersDDList get the teachers list from another SqlDataSource control which the "Select Command" of is:"SELECT teacher_id,teacher_name FROM teachers WHERE (section_id = @section_id)"finallyI want the TeachersDDList to be filled with teachers according to the selected section from the SectionsDDList...So,I enable the Auto postBack function of the SectionsDDListand add the next code for the SectionsDDList_SelectedIndexChanged event:TeachersDataSource.SelectParameters["section_id"].DefaultValue = ((DropDownList)sender).SelectedValue;be aware that both of the SectionsDDList & TeachersDDList have been Bounding to a column...and the problem I have faced is that:Exception Details: System.InvalidOperationException: Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control.maybe you want to know the Stack Trace:[InvalidOperationException: Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control.]
System.Web.UI.Page.GetDataItem() +93 System.Web.UI.TemplateControl.Eval(String expression) +33 ASP.cpanel_managecourses_aspx.__DataBinding__control82(Object sender, EventArgs e) in
I'm putting together a templated, databound control. Presently it works with the following syntax... <cc:ItemChooserControl ID="ItemChooser" runat="server"> <TitleTemplate> <h4><%# DataBinder.Eval(Container.DataItem, "DisplayName") %></h4> </TitleTemplate> </cc:ItemChooserControl>
Problem
What I would like though is that the shorter, simpler Eval would work instead. <h4><%# Eval("DisplayName") %></h4> What I get however when using straight Eval is an error: Databinding methods such as Eval(), XPath(), and Bind() can only be used in the context of a databound control.
Code
I'm databinding to a custom HtmlTableCell... public class TitleTemplateTableCell: HtmlTableCell, INamingContainer { private object m_DataItem; public virtual object DataItem { get { return m_DataItem; } set { m_DataItem = value; } } }
With the following custom DataBind (non-related code removed)...
foreach (object dataItem in dataSource) { TitleTemplateTableCell title = new TitleTemplateTableCell(); TitleTemplate.InstantiateIn(title); // TitleTemplate is the template property title.DataItem = dataItem; title.DataBind(); }
I have a label in a gridview where the text is set to <%Bind("lname")%> . I want to make it say thiis <%Bind("lname" + "fname")%>. I've been having a hard time making .net do this. I also want to add a "," or some other unrelated caracter?
I have a Formview ('formview1') with a pager. I also have a gridview ('gridview1') linked to a SQL datasource ('History'). I need to set the SelectParameter ('Serial') of the datasource to be the value of a field on the current page in the formview. The value i need to get is in the ItemTemplate and is a label called 'SerialNumberLabel'. So, something like:
<SelectParameters> <asp:ControlParameter Text = "Eval fromview1.currentpage.itemtemplate.SerialNumberLabel" >
I also need to ensure that the SQL source and gridview rebind when the pager is activated.
i am developing a tree view component which should be data driven and amendable instead default layout provided by .net can we change that proper hierarchial structure like organization chart is there any chance to provide with an hyperlink to redirect other page or content view control below to display the content related to it.
The amount of li elements that will be rendered into each ul is determined at runtime. Each link in a li belongs to into a specific ul (the one containing a specific caption. Imagine this as a kind of a treeview with nodes and subnodes) During the bind Event I need access to an ASP:HyperLink that will be rendered into the a-element. Which databound ASP.Net control should I pick for this? Looks like a repeater in a repeater, which should make the databinding process ugly. I'm thinking about creating this HTML-Output with StringWriters myself.
I have an AJAX tab container with 2 panels within aspx page. Each panel hosts an ascx control. Each control contains GridView and FormView that are databound - 1st control to the parent table and 2nd - to the child. The 2nd control/tab contains standard DropDownList that is bound to the parent values so the user can select a parent to create "child" for. everything works fine except when the parent (on the 1st tab control) is created/updates the ObjectDataSource on the 2nd tab does not getting refreshed. Only after refreshing the hole page I can see the new "parent" value in the ddl on "child" page. I use strongly typed dataset. How I can programmatically refresh the DataSource? Simple rebinding didn't make a dent. Do I need to refresh page, the tab container, tab panel?
I need a form that displays three columns drawn directly from a database (no problems here) as well as two fields that require some complex calculations. Not only am I lost as to how to incorporate the calculations into the control, I don't know exactly how to write the calculations. I am working in Visual Web Developer 2008 with Vb.NET.
The first of the two fields should take the sum of all payments made by a given customer and divide it by a DailyMembershipRate, returning a DaysPaid variable. It should take this variable and a CustomerSince field for that particular customer and calculate a PaidThrough field.
The second of the two columns similarly requires the DaysPaid variable described above. It should subtract the CustomerSince field from the current date and return the value in days, giving a MembershipDays variable. Finally, it should subtract MembershipDays from the DaysPaid variable, again returning a value in days, and then multiply this by the DailyRate value for a Credit/Deficit field.
I realize this is a lot, but I haven't been able to find any documentation either online or in VWD or ASP.NET texts on this topic. I could really use some fellow user input.
I have DataList control and I want to assign to it's edititemtemplate some User Control. The problem is I can't find when I should databound UserControl to data, as my UserControl doesn't have static look (it renders different depending on some property values and datasource).
I was try to simply set my user control in edititemtemplate
I'm working on a website to showcase some of my bird photography, using ASP.NET 2.0 and C# with a SQLServerExpress backend.What I have right now is a ListBox bound to my database that displays a list of common names of birds and when the user clicks on an item in the listbox the main image on the page is changed to the image for that bird. For style reasons I want the listbox to always be a fixed size and because I specify the size (using CSS) a vertical scrollbar appears. My problem is that I want to provide my own images of arrows that go above and below the box such that when the user hovers over an arrow the box scrolls slowly and when the user clicks an arow the box scrolls quickly. Finally, my main problem is that I want to get rid of the ugly default vertical scrollbar that comes with ListBox.
Can you guys help me figure out how to do this? I don't mind using a different control other than ListBox as long as it is available in ASP.NET 2.0 and as long as it can be bound to my db. I also don't mind using JavaScript (which I'm sure I'll end up doing for the hover effects). Right now I'm fooling around with subclassing the ListBox control but I've never subclassed a control before so I'm somewhat clueless.
I'm using a gridview to extract a set of records. I need to add another field to the gridview, which can calculate the difference between a date associated with each record and the current date.
In my asp.net web page i have a dropdown box. Say like i have to bind EmployeeName to this dropdown box to show up as items.
I am using a dataTable to bind to this grid by having two columns in DataTable (EmployeeId and EmployeeName). But i am only binding the EmployeeName to the dropdown list box.
In the UI, after the user selects an Employee, I need to pass that employee's id to a function. Is there any way, i can directly pass the underlying data (EmployeeID in the DataTable attached to this dropdown), when the user selects the EmployeeName from the dropdown. Or i will have to make a roundtrip to the database and get the selected Employee's Id and then pass it to the function.
I want to know where lies the difference between these two.I had a google search on this topic and a lots of replies and each of them tell the same thing:
Eval means one way binding(i.e;readonly) Bind means two way binding(i.e;both read as well as write the datasource)
but none of them explained it more clearly.all i want to know is how can i use the Bind to update/insert something from the datasource?
I got the difference between Bind and EVal from here. Bind will do both way reading and writing. And Eval do only reading. So any function only for writing?