What a strange behavior in AutoComplete in DataGridViewCombobox column?

问题

I am using the (EditingControlShowing) event to Enable AutoComplete in DataGridViewComboBox Column.

private void dataGridView1_EditingControlShowing(object sender,  DataGridViewEditingControlShowingEventArgs e)
{
    if (e.Control is DataGridViewComboBoxEditingControl)
    {
        ComboBox combo = (ComboBox)e.Control;
        ((ComboBox)e.Control).DropDownStyle = ComboBoxStyle.DropDown;
        ((ComboBox)e.Control).AutoCompleteSource = AutoCompleteSource.ListItems;
        ((ComboBox)e.Control).AutoCompleteMode =  System.Windows.Forms.AutoCompleteMode.SuggestAppend;
    }
}

But it has a strange behavior, when I type some characters then I leave the cell (Tab or right key), the value did not change.
But if I repeat that, the value will change. From Here, you can download the source code and (EXE) video that explains the problem.

Could you please help me to make it work correctly?

回答1:

It appears that for that first entry into the combobox the tab no longer triggers the commit of the value. No idea why this is so, but it appears that handling CurrentCellDirtyStateChanged and committing the edit fixes it.

void dataGridView1_CurrentCellDirtyStateChanged(object sender, EventArgs e)
{
    // You could also check here to see if the cell in question is the combobox
    if (dataGridView1.IsCurrentCellDirty)
    {
        dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);
    }
}

回答2:

I solved it like this :

private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
    if (e.Control is DataGridViewComboBoxEditingControl)
    {
        ComboBox combo = (ComboBox)e.Control;
        ((ComboBox)e.Control).DropDownStyle = ComboBoxStyle.DropDown;
        ((ComboBox)e.Control).AutoCompleteMode = System.Windows.Forms.AutoCompleteMode.SuggestAppend;
        ((ComboBox)e.Control).AutoCompleteSource = AutoCompleteSource.ListItems;
        combo.Validated -= new EventHandler(combo_Validated);
        combo.Validated += new EventHandler(combo_Validated);

    }
}

public static object GetPropValue(object src, string propName)
{
    if (src == null)
        return null;
    return src.GetType().GetProperty(propName).GetValue(src, null);
}

void combo_Validated(object sender, EventArgs e)
{
    Object selectedItem = ((ComboBox)sender).SelectedItem;
    DataGridViewComboBoxColumn col = (DataGridViewComboBoxColumn)dataGridView1.Columns[dataGridView1.CurrentCell.ColumnIndex];
    if (!String.IsNullOrEmpty(col.ValueMember))
        dataGridView1.CurrentCell.Value = GetPropValue(selectedItem, col.ValueMember);
    else
       dataGridView1.CurrentCell.Value = selectedItem;

}

来源：https://stackoverflow.com/questions/12216530/what-a-strange-behavior-in-autocomplete-in-datagridviewcombobox-column