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When does DataBinding update? How to force an update?

I'm wondering about the mechanics of databinding.

Say that a textbox is bound to a property of a business object. The
business object is a "Person". The control is a textbox called
"ctlFirstNa me", and it's bound to the "FirstName" property of "Person".

Why doesn't the following work?

Person p = new Person();
p.FirstName = "Jack";
// ctlFirstName is TextBox on my form
ctlFirstName.Da taBindings.Add( "Text", person, "FirstName" );
Assert.AreEqual (form.textBox.T ext, person.FirstNam e); // Works!
ctlFirstName.Te xt = "Bill";
Assert.AreEqual (ctrlFirstName. Text, person.FirstNam e); // Fails
// Expected control & datasource to both be "Bill"
// But control is Bill & datasource is still "Jack"
When you type text inside a bound textbox and then tab out of the
control, the datasource is automatically updated with the new data. What
exactly triggers the exchange of data between a control and its
datasource? It seems to happen after the Validated event.

Is there a way to force the exchange to happen? How can you
programmaticall y force a bound textbox to update its datasource?

Nov 16 '05 #1
0 5429

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