LINQ - Databinding questions

[Dan Tallent]

I have a form I'm playing around with that has some text boxes on it. I am
using SQL 2005 for my database.
I have a single table which I have created an object entity for. Customer

On the form I set the DataBindings Text value to "customerBindingSource -
CompanyName" on one of the textboxes.
The customerBindingSource was generated by the IDE and is pointing to the
Customer entity I created earlier. The CompanyName is a field within the
entity and underlying table.

During runtime I am using the follow code:

//----------------------------------------------------------------------------------
// This line is where my problem is.

this.CDC = new CustSiteDataContext(ConnString);


// Retreive customer record


var queryCust = from cust in CDC.Customers

where (cust.CustomerID == 100) && (cust.CompanyID == 5)

select cust;

this.customerBindingSource.DataSource = queryCust;

//----------------------------------------------------------------------------------

This works great, it reads the data in, I can make modifications and when I
click my button to save I execute:

this.CDC.SubmitChanges();

If the user wishes to abandon the changes, the idea is they can click a
button to do so. This code appears to work however I have to recreate a
new instance of the CustSiteDataContext for this to work.

In prior attempts I was looking at the refresh method, but I could not
figure out how to write it.
// CDC.Refresh(System.Data.Linq.RefreshMode.OverwriteCurrentValues);

Is the method I am using above the best/only way to implement "abandon"
changes ?



Thanks,

Dan

 

[Marc Gravell]

Largely, yes. Getting a fresh data-context is the safest way of
ensuring you aren't keeping any abandoned changes. You shouldn't keep
a data-context around for too long anyway; they are intended to be
locally scoped, not last for the duration of an app.

Marc

 

[Dan Tallent]

Thanks for the response. My idea was to only keep the DataContext while the
user resides on that particular form. Its great to know I'm not completely
lost.

Thanks
Dan