CODEWITHSUNDEEP
wpfcomboboxuppercase
Alex
Alex

Reputation: 811

WPF ComboBox, force input to UpperCase

I have an editable WPF ComboBox with TextSearchEnabled. I need to force the user's text input to uppercase when they type to filter the ComboBox.

I was thinking of modifying the textbox that is part of the control (named 'PART_EditableTextBox') to set CharacterCasing="Upper", however I can't quite figure out how to do this.

Do I need to use a trigger, or modify the template in some way?

Upvotes: 3

Views: 11278

Answers (4)

Bast73
Bast73

Reputation: 83

I found that post where the attached property is used. That permit to use that for all of your ComboBox without rewriting the code.

Upvotes: 1

Alex
Alex

Reputation: 811

This works and seems like a reasonable solution:

protected void winSurveyScreen_Loaded(object sender, RoutedEventArgs e)
{
    (comboBox.Template.FindName("PART_EditableTextBox", cbObservation) as TextBox).CharacterCasing = CharacterCasing.Upper;
}

Ensure that the combobox is not collapsed on loaded otherwise the template will not be found.

Upvotes: 10

Amsakanna
Amsakanna

Reputation: 12934

private void TextBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
{
    Textbox editableTextbox = sender as Textbox;
    foreach (char ch in e.Text)
    {
        if (Char.IsLower(ch))
        {
            editableTextbox.Text += Char.ToUpper(ch);
            e.Handled = true;
        }
    }
}

or try creating an attached behaviour for the textbox

Upvotes: -1

slaphappy
slaphappy

Reputation: 6999

IMO, the quicker way is to set the UpdateTrigger to PropertyChanged and, in the data object, uppercase the value when it is updated.

Upvotes: 3

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