Web Forms :: Accessing A Linq Entity From A FormView?
Feb 23, 2010
I have extended a Entity class created by the designer (Linq to SQL). I have create a partial class called Promotion (App_Code/Promotion.cs) and I have added some new methods. But now, I want to access this methods from a FormView control and I dont know how to refer to the instance of the entity.
In the ForView, I can do:
[Code]....
And now Im accessing to one STATIC method of my completed Promotion class (App_Code/Promotion.cs)
But I dont know how to do to call a instance method
[Code]....
My firs though was to use the reserved word this, jejeje, but this refer to the web page instance..
I would like to ask if it is possible to access data on a master FormView from a nested detail FormView.
I have a main form (master) with several tabs (detail) and would like to display a label with text from main form that is hidden by the tab at the moment of editting. My asp page looks like this.
[Code]....
Is it possible to get the value of the label CompanyTextLabel from CompanyTextBox using just ASP.NET expressions or something similar without writing c# code in .cs file?
I am trying to munipulate date in a label associated to a textbox inside a formview. The label is a textbox charater counter. I receive the error "NullReferenceException was unhandled by user code." The code works fine without the formview but now I need the formview to have a gridview associate data to the formview.ASP.NET Code
string strCondition = "FirstName=='abc'" from p in People.Where(strCondition) select p
In our architecture we are usign both Linq-Sql as well Linq-Entity. So please give some thoughts wehter it is possible or not and is there any way to perform this?
I am getting error while accessing entity model from web serviceSystem.NotSupportedException: SQL Server Compact is not intended for ASP.NET development. at System.Data.SqlServerCe.SqlCeRestriction.CheckExplicitWebHosting() at System.Data.SqlServerCe.SqlCeConnection..ctor() at System.Data.SqlServerCe.SqlCeProviderFactory.CreateConnection() at System.Data.EntityClient.EntityConnection.GetStoreConnection(DbProviderFactory factory) at System.Data.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) at System.Data.EntityClient.EntityConnection..ctor(String connectionString) at System.Data.Objects.ObjectContext.CreateEntityConnection(String connectionString) at System.Data.Objects.ObjectContext..ctor(String connectionString, String defaultContainerName) at DataModel.LabTestDBEntities..ctor() in d:projects4.0 vs2010labtestlabtestsolutiondatamodeldbmodel.designer.cs:line 26 at DataService.Service1..ctor() in D:Projects4.0 VS2010LabTestLabTestSolutionDataServiceService1.asmx.cs:line 23
I have added a table to my FormView Edit template for structure and a button that pops up a form for information.
When the button is clicked I want a check box in neighboring cell to become checked. But I am having problems in the VB code behind, establishing the name of the check box to change its state. Its something like this....
I have a Customer database table with a text field named customerPicture with the name of the JPG file.
I have made a Customer Entity class with the LinQ to SQL Designer.
I also have a FormView displaying Customer instance binding with a LinqDataSource.
My problem is:
I want to make some modifications when some control want to bind the customerPicture field.
For example, when my FromView want to show the field customerPicture I want to return not only the JPG file name, I want to modify this string to add the complete file path and perhaps resample the image to a determinate width and height.
I know that is posible to defeine a partial class named Customer to implement certains partial methods, like OnCustomerPictureChanged(), but I dont know how to do this.
If I make, in this Customer partial class, a new method, for example getResamplePicturePath(), how could I invoke it from a FormView?
I keep getting a null reference when I try to access a listbox inside the EditItemTemplate of a formview. I check the mode before accessing the control (Formview1.CurrentMode) to make sure it is in edit mode and even set it manually to edit mode again! But formview1.findcontrol("blah") returns null. Formview1.EditItemTemplate does not have a FindControl method, not sure what else to try.
I have a UserControl inside the ItemTemplate of my FormView and I need to access it in order to get an event fired off. As the UserControl is inside the template, my event cannot see it!
I want to delete entity from linq class this entity has one to many relationshipe with another table so I want to delete all entities related to this one for example I want to delete classroom so i should delete all student is this classroom fisrt i don't how to delete all these student in one time
Instead of usng FormView with SQLDataSource control, I like to use it with LINQ-to-SQL. For example, can I write my own LINQ to SQL for Edit and Update? Will FormView control work in this way?
I've got a ListView with a DataPager on one page and then a FormView with the items detailson another page. There is an Image in the ListView where the user can click on the image andthat takes them through to the page with FormView on it.If the user goes through to the FormView page and then press's back on the browser to takethem back to the page with the ListView on if the user then click's on the DataPager it takes
I'm trying to use formview in order to do insert of a new entity object (called Customer) Customer has a reference to another entity called Address. How can I fill both of them in the same formview?
I am using a form view control which has two binded textbox. Now at this level it works fine and the textboxes show the values from database. But when i insert a panel inside the form view and move these two textboxes inside the panel, they dont show any values. What could be the reason for this?
Im working on a greenfield project and have to make a decision on the technology we'll use for the data access layer. Ive used LINQ to SQL for a few years and am happy and comfortable with this, but now with entity framework available this is another method to consider. Are there any pitfalls using entity framework as opposed to LINQ to SQL ? Ive read that there are performance issues with entity framework, is this true? Id really like to get an overall feel for using one method over the other, anyone have any thoughts/comments/recomendations?
Type 'System.Data.Linq.ChangeTracker+StandardChangeTracker' in Assembly 'System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable
have read all threads but still cant solve the error. I can do insert update and delete but dont know where exactly the error occurs and how??
How can I update an existing LINQ entity? This code gives me: "Cannot insert an entity that already exists." Any better practises on updating/inserting with linq?
foreach (ListViewItem lvi in lvStudents.Items) { HiddenField hfStudentID = lvi.FindControl("hfID") as HiddenField; CheckBox cbPresent = lvi.FindControl("mycb") as CheckBox; int sInt = Int32.Parse(hfStudentID.Value); dc = new DataClassesSODataContext();//I renewed the dc to make sure that wasn't the problem? var currStudent = dc.students.Single(x => x.studentID == sInt); grade g = dc.grades.Single(x => x.subjectID == subjID || x.studentID == sInt); if (g == null) { g = new grade(); g.subject = dc.subjects.Single(x => x.subjectID == subjID); g.student = currStudent; g.present = cbPresent.Checked; dc.grades.InsertOnSubmit(g); } else { g.present = cbPresent.Checked; dc.grades.Attach(g, true);//I tried both attaching and inserting } } dc.SubmitChanges();
what is diffrence between Entity Framework and LINQ to SQL i cant yet find a good blog on this i have read that in LINQ to SQL only one to one mapping is possible but Entity Framework allowes many , is it right? if so i dont understand this
I have a new project where I want to use MVC (I will be learning as I code), and I have never used linq or entity (or mvc). Which should I use? Does it matter? I will be having a lot of different databases, from Oracle to FoxPro.
