I have a ListView with a LinqDataSource that's not displaying data. Here is my source code:
[Code]....
why the data won't display? As far as I can see, I've done everything right.
I am trying to populate the ListView using LinqDataSource data source but the issue I am having is.I need to load the listview on Search button click action.
IN the page_load I kept like this:
===========================================
LinqDS.Selecting += new EventHandler<LinqDataSourceSelectEventArgs>(LinqDS_Selecting);
protected void LinqDS_Selecting(object sender, LinqDataSourceSelectEventArgs e)
{
e.Result = ObjectDS;
}
=============================================
This works fine but this happens on page load,i want this binding to happen on button click?is there a way to do this?
With the gridview I can create a template field to query across associations but I don't see how its possible to do that with the listview (?). I tried to create associations in the eval fields
(ie productId.Brand) where productId is in the Reviews table and is associated with the Products table - and Brand is a member of the Product table but it was no go?
[Code]....
<b>Title:</b> <%# Eval("Title") %>
This was a pretty disappointing moment - when databinding, using Eval("Contact.LastName") would work. It nicely evaluates the related Linq object's member LastName. If the "Contact" object is null, no error is thrown... instead the field is simply null.
However, the same does not hold for sorting - if there exists a null entry (this object does not have a Contact) then the LinqDataSource throws a NullReferenceException. This means that, if you ever have nulls on your foreign-key objects, you can't use sorting headers in the ListView.
This makes the feature moderately useless - I have to roll my own properties for every single field I'd ever want to sort on. That's insane.
I'm trying to add a LINQ datasource to my ListView control but it doesn't pick up the data context that I created. All it shows as options in the dropdown list are AJAX objects. What could be the possible causes for this?
View 3 RepliesIf I have a Linqdatasource that isn't connected to a a bound control on my page how do I use the data source to read data in the code behind. ie
var query = (from x in linqdatasource select x)
What I actually want to do is create a data array (myArray) within the code, read all of the data from the linqdatasource (selecting 1 field to form tableDataArray), then compare the two arrays and then write (insert) those into in myArray that are not already in the datasource to the datasource (ie execute an insert back on the datasource).
How can i retrieve the data in linqdatasource in code behind?i have a dynamic database design with column storing the datatype eg. text, int, date.i need to retrieve the value in order to populate the control and bind it.
View 5 RepliesI am having trouble finding how to solve the following issue :
I am using nested listviews to display Sales and Sales details.
The main ListView displays General Information about Sales and the child ListView displays the detailed information about one sale. the child listview is shown only when the user clicks on a link (see included code, DataBind is made on PageLoad) :
ASPX Markup Code :
[Code]....
C# Behind Code :
[Code]....
If I removed the datapager part, I can manage show/hide the child list view on the button click event. but if I want to use the DataPager with the PreRender event handling, the child listview is not longer shown on button click.
I have a FormView bound to LinqDataSource, that is intended to allow editing of a single product's details, that is selected from a GridView. The LDS has a Where parameter set to point to the GridView control (i.e. a ControlParameter).
View 1 RepliesI have a button and a few filter fields (dropdownlists, text fields etc.) and I'd like the ListView to display records once the user clicks on the button. I am using the ObjectDataSource control with a Listview. I am setting the TypeName and SelectMethod values in the Page_Load when page is postback-ing so that the ListView does not populate on Page Load. On the ObjectDataSource_Selecting method, I'm setting the filter fields' value's in a class object and at the end I'm setting the InputParameter as that object, something like this
[Code]....
However, this assignment cannot be done as-is and I'm not sure how I should "cast" it to make it work.
How I can bind texbox to one property from linqdatasource?
I mean something like databinding contols in c# app
I'm trying to delete a item from the listview. I can delete the item from the database ok, but the listview item does not get removed, I could do a Response.Redirect to redisply the page but this is overkill? Below is my code:
[Code]....
Im trying to build a where clause in c# for a LinqDataSource, but I cant get it to work, heres my code
[Code]....
when I set category to 'Concerts' tyhe where clause is
'Category = Concerts'
this generates an error telling me there is no column called 'Concerts'. I assume I somehow have to enclose the search term in quotes, Ive tried single and double quotes, but nothing works.
So I need to take the literal "SELECT....FROM Bay....WHERE Warehouse=1 and ((BAY LIKE '1.0%' or BAY LIKE '2.0%'))I have set up a linqdatasource on my asp page and I want to bind that to a gridview. Here is the start of the HTML:
<asp:LinqDataSource
ID="dsBays"
runat="server"
ContextTypeName="CartonInventory.CartonInventoryDataContext"
EnableUpdate="True"
[code]...
How do I add a parameter so that it includes the LIKE statement?
I have a problem with using the listview.When I want to update or cancel the update, the listview doesn't leave the edit mode.When I clicked the updatebutton, the methode Listview.Itemupdating is fire and changes the database. But then nothing happened. Even if i set the itemindex -1.The Listview.Itemupdated does also not fire.This is the code.
[Code]....
The code:
[Code]....
I'v been using SqlDataSource and ObjectDataSource for a while.I would like to know about LinqDataSource and EntityDataSource. Therefore I have 2 questions to ask.1) Why do we need to use those twos? 2) In which cirmustances (Requirements) developers are using LinqDataSource and EntityDataSource?
View 1 Repliesi am an asp.net beginner, i am a windows application programmer and currently i am working on big project " Human Resources" and i need to allow the users to apply for jobs using a web page.in windows application, i can use the bindingsource to bind textboxes and comboboxes to the fields of an object from L2S.and to bind the datagrid also to the detailed data and the page will be for inserting issue only,i.e i don't need to bring the data of applicants and certificates from the database, i just need some lookup data like maritalstatusCombo and availableJobsList things to allow the user to choose from.how can i do this using linqdatasource.
View 3 RepliesI use LinqDataSource and GridView.
I need an old value of field "PictureBig" in RowUpdating handler like this:
e.OldValues["PictureBig"]
To achieve this I use bound unvisible literal in edit item template...
<asp:Literal ID="ltBig" runat="server" Text='<%# Bind("PictureBig") %>' Visible="false" />
Is there any better ways of doing this?
I am trying to program the where prameters for this in code behind in C#, and is there really no way to do more than one parameter? Or am I not understanding this correctly? It seems only the 2nd parameter gets executed, no matter which one is at begining. I debug and seems they both get executed fine, but my listview doesn't get filtered and instead only the 2nd paramter works. Look at my code:
Also, if I do myLinq.Where = "division ==1 and someotherInt = 2", it works fine, but if I do two different data types, it will throw error. Since I want to filter with two different data types, hwo do I do this?
Parameter pram1 = new Parameter();
pram1.Name = "division";
pram1.DbType = DbType.Int32;
[code]...
I'm having a question about the LinqDataSource. Does anyone know if it's possible to perform multiple inserts with the LinqDataSource? Let's say for example that I have 2 tables.
Table A
AID = PK autoincrement Name AddressA FK AddressB FK
Table B
BID = PK autoincrementStreetNumberPostalCodeCountry
These tables are just examples to clarify my question. Let's say that I have a FormView with a LinqDataSource where the user can enter his name en a billing address (A) en delivery address (B). Now I would like to know if the LinqDataSource is able to insert 2 records in table B and use these ID's to insert them in table A together with the name?
I need to retrieve data using a date as an input parameter. I created a WhereParameter and passed in a date value that I know to exist in the database, but no data is returned. Heres my code
[Code]....
Ive passed in '02/06/2010' as the date, in the database, the Startdate column has several values of '2010-06-02 13:08:50.503' so I guess its not being found because of the time part. Whats the best way to make sure that I retrieve the correct data ? Im not concerned about the time at all, I just need all rows for 02/06/2010.
Where can I find documentation on the syntax that is expected for LinqDataSource.Select? It seems to be different from what I would do with Linq inline in C# code. For example, concatenateing something in Linq I would normally just do this in the projection:
new { FullName = (person.FirstName + " " + person.LastName ) }
However, with a LinqDataSource the only way I've found to do this is like this:
new ( String.Concat(person.FirstName, " ", person.LastName) as FullName)
I literally spent hours trying to figure this out, and only succeeded when I found a blog where someone gave this verbatim as an example. So I still don't understand why the syntax is different, the braces versus parens, aliasing, Concat operators. Next time I do this I want a better understanding so I am not playing this guessing game. It's like being handed a compiler, and trying to write a program when you don't know what language the compiler compiles.1. Are there different "flavors" of Linq? Like a VB Linq, and C# Linq?2. If so, is the LinqDataSource using a VB flavor of Linq?3. Really, what is really important to me, where can I find documentation on this particular falvor of Linq that the LinqDataSource expects? The documentation for the LinqDataSource itself gives nothing more than extremely simplistic examples.
I just started working with LinqDataSources and I was wondering how you retrieve values in a FormView DataBound Event.
With an ObjectDataSource I believe you can grab them like:
[Code]....
Is there a similar way to acheive this with a LinqDataSource?
I have a gridview on a page and based on the row selected I need to fill out a form view (dynamic data enabled) from a linqdatasource. On gridview_sleectedindexchanged I create the linqdatasource and set it as the datasource for the formview. It displays nicely but clicking update returns a "Could not determine a MetaTable" error for the datasource mapped.
THe goal is to create a single page that allows users to select a row then get the appropriate data, create an updateable formview so further edits can be done. Do not want to scaffold.
I have LinqDataSource ID="LinqDataSource1" with values - EnableDelete="True", EnableInsert="True" EnableUpdate="True" on my ascx page, furthermore GridView, button a few textboxes, where a fill new values, which I would like save in my database. After click on button I insert new value to the table throught in function stored in ascx.vb page. It is works, but I don't know, how I refresh GridView on ascx page. I tried
LinqDataSource1.DataBind()
GridView1.DataBind()
without any good result, I must refresh page manualy (F5).