Question

The answer to this question may turn out to be, ‘Don’t use typed DataSets without using the Binding Navigator.’ I am curious, however, about the behavior I’m seeing.

So, I created a form where every control was dragged from the data sources explorer. I deleted the Binding Navigator because it is ugly and inappropriate for this particular form. I added a ListBox and set the DataSource to the BindingSource.
Notice that the ListBox is not bound, it is just filling itself from the BindingSource. By some magic that I wasn’t counting on, moving around in the ListBox is navigating the BindingSource and all other controls are updating accordingly.

I can make changes to the bound controls and explicitly call EndEdit on the BindingSource and then update the DataSource through the Table Adapter. Works great.

When I make changes in the bound controls and click a new option in the ListBox, I want to be able to check for changes and prompt to save or reset if there are any.

Here is the strange part that I haven’t been able to figure out.

No matter what event I attach to, DataSet.HasChanges doesn’t return true until the second ListBox change. I’ve searched and tried dozens of suggestions, most of them ridiculous, but a few that seemed promising. No luck.

Edit: It isn’t the second click that is significant, it is when you click back on the original (edited) item.

Answer 1

Since asking the question, I’ve learned a bit more about BindingSources, DataSets and TableAdapters.

Here is what works:

    private void MyListBox_Click(object sender, EventArgs e)     {         this.myBindingSource.EndEdit();         if (myDataSet.HasChanges())         {             if (MessageBox.Show('Save changes?', 'Before moving on', MessageBoxButtons.YesNo) == DialogResult.Yes)             {                 myTableAdapter.Update(myDataSet.myDataTable);             }             else             {                 myDataSet.RejectChanges();             }         }     }