LINQ to objects with linqdatasource and DetailsView

Question

VS 2008 professional C#
Hello ! I have a class with properties and I need to give the user a way to edit it. The best for me is to use a DetailsView. So far I managed to set the DetailsView.DataSource only in code. But I would like to be able to define some templates for edit. I tried to set a LinqDataSource and set its ContrxtTypeName and TableName and and set the DataSourceID of a DetailsView to it. I was hoping to see my class properties in the wizard opene when pressing the "Edit Fields" of the DetailsView so I can define what I need to.  Well - no luck !! Is there a way to do this ? Is LINQ to objects accessible at design time?
I read many post on LINQ to Objects, and most of them show examples using the console.
Thanks in advance   Gil Yoktan

Answer 1

Hello Gil,

I tried what you describe, and it worked for me. Here is what I did.

1. Create a new ASP.NET Web Application with VS
2. Create two classes: MyDataContext and MyClass. See below.
3. Drop a LinqDataSource and a DetailsView on the default page
4. Set the LinqDataSource as the DataSource for the DetailsView
5. Set ContextTypeName = "WebApplication1.MyDataContext" and TableName = "MyTable" on the LinqDataSource
6. Click "Edit Fields..." on the DetailsView

I see the properties in the list of selected fields and under BoundField. Note: you may have to click "Refresh Schema" on the dialog.
Does it work for you this way?

Here are my classes:

public class MyClass
{
  public int IntProp { get; set; }
  public String StringProp { get; set; }
}

public class MyDataContext
{
  public IEnumerable<MyClass> MyTable { get; set; }
}

Fabrice

Answer 2

Additional information: to provide the data to the LinqDataSource, you can use the ContextCreating event of the LinqDataSource.

1. Add OnContextCreating="LinqDataSource1_ContextCreating" to the LinqDataSource's tag
2. Add the following method to Default.aspx.cs:

Code Block

protected void LinqDataSource1_ContextCreating(object sender, LinqDataSourceContextEventArgs e)
{
  var context = new MyDataContext();
  context.MyTable = new[] {
    new MyClass { IntProp = 1, StringProp = "Un" },
    new MyClass { IntProp = 2, StringProp = "Deux" }
  };
  e.ObjectInstance = context;
}

 

 

Answer 3

Hello Fabrice. Thanks for responding so quickly
Maybe I forgot to say that I work with winforms
I downloaded an example from the net working with the Northwind database, and it works OK. I tried to change the database to mine with tables with foreignkeys as in the Northwind DB. In the example the work is
1 - create a class with the dbml
2 - compile it
3 - create another project in the same solution with a form
4 - create a datasource -> object from the dbml
5 - drag the table to the form

In my implementation the master table has the datagridview option and the details table - does NOT
What I ask is what is the Microsoft algo which fills the dropdown list - with or without the datagridview option?

Any help will do
Thanks in advance  Gil Yoktan