How do I edit data in a data table that is bound to a combo box without using a datagridview? - vb.net

Question

I am using a combo box that is bound to a data table by the primary key. By selecting a value from the dropdown I am able to populate several textboxes in a form. I can easily add a new record to the data table. Occasionally I need to edit an existing record but I cannot discover the "index" of the row corresponding to the selection in the combo box even though I can populate the textboxes. Are there any methods to use with "datarow" to determine what record the "Pointer" is pointing to? If so perhaps then I could reference that datarow and write new data to the datatable, then update using a dataadapter... Any help would be greatly appreciated.

Answer 1

You're trying to solve a problem that doesn't exist. You don't need to know the index of the row or the row for that matter. What you should be doing is:
Binding your DataTable to a BindingSource, which you add in the designer.
Binding your BindingSource to your ComboBox AND your TextBoxes.
Select records in the ComboBox and edit in the TextBoxes as you like.
When it's time to save, call EndEdit on the BindingSource to ensure any pending edit is committed to the DataTable.
Use the same data adapter to save the changes from your DataTable as you used to populate it in the first place.
The binding would look something like this:
myDataAdapter.Fill(myDataTable)
myBindingSource.DataSource = myDataTable
With myComboBox
.DisplayMember = "DisplayColumn"
.ValueMember = "PKColumn"
.DataSource = myBindingSource
End With
myTextBox.DataBindings.Add("Text", myBindingSource, "EditColumn")
The saving would look something like this:
myBindingSource.EndEdit()
myDataAdapter.Update(myDataTable)
At no point do you have to care what rows were edited and where they are in the DataTable because Update will just save all changes.