Question about ComboBox and Linq to Sql for Winforms...

Question

Edit: More than a day. Still no answer! Is question not clear?

I have ComboBox bound to BindingSource which in turn is bound to Linq Table.

Also, ComboBox is filled from datasource which is a Linq Table.

I want to assign new value to one of properties of BindingSource.Current whenever user selects item in ComboBox. I understood from MSDN that I need to use SelectionChangeCommitted event of ComboBox.

Here is pseudo code:

myCB_SelectionChangeCommitted(...)
{
    var val = myCB.SelectedValue; //I get selected value from user.
    var q = bindingSource.Current as XYZ;
    //Ommitted validation code to check if q is okay to work with
    q.SomeProperty = NewCalculatedValue; //SomeProperty is bound to label
    //After above line, myCB.SelectedValue is lost!
    //It seems that this event fires **before** selected value 
        //is written to bound data source
}

Q: Do I have to use myCB.DataBindings[0].WriteValue(); ? Or is there a better way?

Thanks in advance.

Answer 1

I would do something like

long index = q.databaseindex;
LinqObject = (from l in DataContext.linqtable where l.index = index select l).First();
   //Make sure you do a check that count > 0 before calling First!
LinqObject.property = value;
LinqObject.SubmitChanges();

This way regardless of how the object is persisted to the ComboBox you'll be able to capture the object from the database and then update it with the value, etc.

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