I'm databinding a radiobuttonlist with a LINQ query like so:
var query = from m in Db.Udt_Menu
orderby m.Name
select m;
this.radMenuSelection.DataValueField = "menuID";
this.radMenuSelection.DataTextField = "name";
this.radMenuSelection.DataSource = query;
this.radMenuSelection.DataBind();
However, when i want to update the record I need to set the selectedindex of the radiobutton to a value from the database. There is a table called udt_PageMenuSelection which has a column called menuID which is a foreign key to udt_Menu.menuID.
When i want to update an existing record, how do i set the selectedindex of the radiolist to the value equal to udt_PageMenuSelection.menuID ?
I am not able to catch the databing mechanism when used with LINQ.I am able to populate the data correclty agaisnt my comboboxes. the thing I am not able to catch is when changing an item in the dropdownlist and set the focus on some other control in my form, the combobox resets to its original value. this way I am not able to send changes back to the database.ave you got any solution, or you need more explanation?:)
I have a user control with a datalist. I just want to do some simple binding but keep getting an object reference not set to an instance of an object error. The following is the code, I am sure I am just missing something simple:
Dim dc As Forms.DataClassesDataContext = New Forms.DataClassesDataContext Dim formQuery = From fq In dc.v_form_questions _ Where fq.FormTypeID = FormTypeID _
[code]...
When I debug, I see values for the formQuery; I am also able to loop through the formQuery and response.write a field out, however every time I try to bind it to a databound control, I get the Object reference not set to an instance of an object error.I initally was using a simple LinqDataSource object, but needed to set the where parameter to the FormTypeID property of this usercontrol. I had a Where condition defined on Page Init, but started getting the object reference error.
how can I display a linq query in a gridview that has data from multiple tables AND allow the user to edit some of the fields or delete the data from a single table?
I'd like to do this with either a linqdatasource or a linq query. I'm aware I can set the e.Result to the query on the selecting event. I've also been able to build a custom databound control for displaying the linq relations (parent.child).
However, I'm not sure how I can make this work with delete? I'm thinking I may need to handle the delete event with custom code.
I am struggling to create a webservice method using LINQ technology and to populate a dropdown in a form. Here is the Webservice code.
[WebMethod]
public string[] GetAllCountries() { LinqClassesDataContext db = new LinqClassesDataContext(); var q = from c in db.ListContinents()select c; return q.ToList() ; }
And here is the form code behind
protectedvoid Page_Load(object sender, EventArgs e) { WSClass WS = new WSClass();//bool ds = WS.GetAllCountries(); var v = WS.GetAllCountries(); ddlContinent.DataSource = v; ddlContinent.DataBind(); }
Working on an ASP.NET 4.0 project, which uses user controls to dynamically generate a form based on definitions stored in the database. One form field would look like this:
[code]....
Behind the scenes the control emits a RegularExpressionValidator based on the RefControl.ValidationFormat property.
This works fine, however the problem is that this architecture only allows us to validate with regexes. Now I need to add date format validation, based on the user's preferences (which aren't dependent on their UICulture).
Reluctant to refactor the entire user control setup, I need to be able to pass a on-the-fly regex pattern to the ValidationFormat property. Currently I'm using a data binding expression to bind the property to a page instance method:
[code]....
Works okay on first page load, but on subsequent postbacks the validation doesn't work. I think the issue is that the data binding expression doesn't evaluate at all, but I'm not sure I understand why. I'm calling Page.DataBind() in Page_Init whether Page.IsPostBack or not, so shouldn't this work?
If you see I'm barking up the wrong tree, any alternative solutions to the same problem are also welcome.
EDIT
Managed to solve this problem. The issue was with the way ASP.NET page life cycle invokes the user control's events before the page's own events. The control values were being initialized before the data binding on the page could happen.
Because I still need to do the control initialization before Page_Load to subscribe the controls to viewstate, I simply moved the initialization logic to the Page.InitComplete event so the call to Page.DataBind() could get called first.
I am writing a plugin to help with a current ERP system we have that I am not allowed to modify the data structure at all. The table I am dealing with has over 100 columns and I am wanting to set my linq object propertychanged event and submitchanges or do I really have list out each property and set it equal to the new one?Below is an example of what I am trying to do:
Like that I have large number of controls on my form. I have dought, if I assigned like this, db.usp_ATI_FetchPatientDetails(iPatientID).ElementAt(0).Last_Name.ToString(); to every control, then I have set of controls like,
My question is that, for each control the Stored Procedure called or not? If it is yes then it is time consuming and I need to use LINQ to DataSet or LINQ to Object rather than to call SP for each control. What is difference between LINQ to DataSet and LINQ to Object?
I've build a linq query.But i want a random selection so its not always ID : 1,2,3,4,5,6 How can i randomize this var? I like to bind it to a repeater.//TagCloud:
Random rand = new Random(); var tc1 = from i in JumpTide.cms.menu.GetMenuItems(32) select new
Would a call to a database be called if you put the databind method in the PreRender event of a listbox and the listbox was rendered on the screen for example? This is a specific example regarding a listbox, but basically does code in PreRender only get called if the control is rendered on the screen. If this is so, is it good practice to put code into PreRender such as databinding?
((Alert)Container.DataItem).AlertId.ToString() the value I get for SystemObjectRecordId in debug is null (but it still works when assigned to the text attribute of a literal).
5) The location of the User Control is default.aspx and the control is comments.ascx. The code files do not share a namespace.
6) I have tried manipulating the OnItemDataBound property of my repeater but since I have proven with the literal that data is getting bound using a declarative value I am not sure what else I could be doing inside the method logic of OnItemDataBound.
Once the end-user makes a comment in the UI, the SystemObjectRecordId value (which should have already been assigned when the page loaded - and we know it does in the case of the literal) should get passed to the codebehind of the custom usercontrol:
[code]....
No matter what I do, I always get zero for SystemObjectRecordId when passed via the custom user control I have on my default.aspx page.
Here i want to access the comment table, with the comments related to the taskID
</ItemTemplate> </asp:Repeater>
I've tried using: <%#Eval("Comment.Comment1")%> but that throws this error:
DataBinding: 'System.Data.Linq.EntitySet`1[[Assistr.Models.Comment, Assistr, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' does not contain a property with the name 'Comment'.
My code-behind:
var tasks = db.PersonalTasks.OrderBy(x => x.IsDone).ToList(); PersonalTaskRepeater.DataSource = tasks; PersonalTaskRepeater.DataBind();
Do I need to use 2 repeaters to do what I want to do or? :)
I'm trying to build a webpage without using any asp.net data binding controls ( listview, repeaters etc.)that I'm trying to do is to use stored procedure to get all necessary items, loop through them, and bind to labels, images etc.The problem is when i want to repeat .aspx code. I'm able to do everything i want in c#, but it's really pain to create all the necessary html elements such breaklines, spans, textboxes and so on.I tried to use expression builders, but it only repeats the last value from database.
Here is my code(ASPX): [Code].... c# code: [Code]....
I have Wizard steps in a a Wizard control. Each step looks like a form with textboxes and dropdowns for users to complete. I don't want to lose the data as user completes each of the wizard step.
1. I'm thinking about saving user input to sql database when user clicks the next button with each wizard step but I wonder if this is wise since it would create many runs and writes to the server? If not the best way then what method should I use? I just don't want user to lose data if browser crash or for any reason.
2. Or should I use the DataBinding option in the Wizard? Would this be a better performance?
3. Another concern I have is that there are on average about 7, 8 HTML-Server CONTROLS (I added id and Runat="server" to the regular html controls) in a wizard step. If I load up all 7 steps and each step has 8 controls then is that a lot of controls? Wouldn't that affect performance easily when there are a few more users access this web app? Maybe I shouldn't use Wizard for this then? I should just have 7 forms and each form would have Next and Prev buttons that takes users to whatever page they want?
How can I get asp.net to two-way databind (via Bind("myfieldname")) to a Byte value? I'm storing boolean values in Sql Server to a Byte type and it seems to be looking for boolean. Apparently I need something to convert my datasource's Byte
Looked into creating a method to call like MyConvertMethod(Bind("myfieldname")) but asp.net 4.0 did not allow that with "Bind()" though it allowed it with "Eval()" but Eval only seems to do one way databinding. I looked into the ConvertHandler but seems to be winforms and not webforms.
We are using a DataList with a couple fields inside the ItemTemplate. The one that is giving me trouble is the Hyperlink. The code is below. When the page loads the hyperlink renders like this:
[Code].....
I cannot see where the extra # signs are coming from. They don't appear to be in the field in the table.
I'm new to asp.net. I have a page with formview to read, edit and insert data to sql server 2008. On the page there are textboxes, dropdownlists. The Dropdownlist1 is bound to a lookup table. I also have a pop-up page to add, delete and update data underlying table. The problem is after i insert a new record to the lookup table and close the pop-up page, rebind the dropdownlist on the parent page. I'm refreshing the page with window.opener.location.href ....
but i want only the refresh the dropdownlist on the parent page.
