I am having some trouble with setting a value to ComboBox.SelectedValue and then saving that value using DataBinding.
Example:
// There are five controls on a form, 1 ComboBox (comboBox), 2 TextBoxes (tbx1, tbx2) and 2 buttons (btnNew, btnSave)
DataSet dsFillCombo;
DataSet ds1;
// I fill each DataSet using separate data adapters
// The Combo is Bound like this
comboBox.DataSource = dsFillCombo;
comboBox.DisplayMember = "sectionIds.sectionName";
comboBox.ValueMember = "sectionIds.sectionId";
// So far, pretty basic. Now I bind the controls on the form to my other DataSet
tbx1.DataBinding.Add("Text", ds1, "users.fName");
tbx2.DataBinding.Add("Text", ds1, "users.lName");
comboBox.DataBinding.Add("SelectedValue", ds1, "users.sectionId");
BindingManagerBase bm = BindingContext[ds1, "users"];
// Still pretty basic, I could add more buttons to change the record position, and the values
// would in the form controls would change with the data rows.
// Now for my issue!
// For the btnNew I want to add a new record to the dataset and set the comboBox to the same
// value that it is currently.
private void btnNew_Click(object sender, System.EventArgs e)
{
int i = Convert.ToInt32(this.comboBox.SelectedValue);
bm.AddNew();
this.comboBox.SelectedValue = sid;
}
// Now I click the Save button and...
private void btnSave_Click(object sender, System.EventArgs e)
{
bm.EndCurrentEdit();
}
As soon as I do that an Exception is thrown:
System.NoNullAllowedException: Column 'sectionId' does not allow nulls. ...
If I actually select a new value using the comboBox then the new record is saved without an issue.
Is there a way to set the SelectedValue of a ComboBox from code and have that value recongnized by DataBinding?
Thank you for any assistence.
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From: Brett SlaskiClass [Discussions]: "databinding"
