Open AutoCompleteBox in WPF on control focus

autocomplete, c#, wpf

Solution

I did a quick workaround as if this solution is satisfying for me in my program.

AutoCompleteBox box = new AutoCompleteBox();
box.Text = textField.Value ?? "";
if (textField.Proposals != null)
{
    box.ItemsSource = textField.Proposals;
    box.FilterMode = AutoCompleteFilterMode.None;
    box.GotFocus += (sender, args) =>
        {
            if (string.IsNullOrEmpty(box.Text))
            {
                box.Text = " "; // when empty, we put a space in the box to make the dropdown appear
            }
            box.Dispatcher.BeginInvoke(() => box.IsDropDownOpen = true);
        };
    box.LostFocus += (sender, args) =>
        {
            box.Text = box.Text.Trim();
        };
    box.TextChanged += (sender, args) =>
        {
            if (!string.IsNullOrWhiteSpace(box.Text) &&
                box.FilterMode != AutoCompleteFilterMode.Contains)
            {
                box.FilterMode = AutoCompleteFilterMode.Contains;
            }

            if (string.IsNullOrWhiteSpace(box.Text) &&
                box.FilterMode != AutoCompleteFilterMode.None)
            {
                box.FilterMode = AutoCompleteFilterMode.None;
            }
        };
}

Problem

I'm trying to open `System.Windows.Controls.AutoCompleteBox` on control focus. The event triggers but nothing happens:/ When I start entering some text, the autocomplete box works fine. What am I doing wrong? ``` AutoCompleteBox box = new AutoCompleteBox(); box.Text = textField.Value ?? ""; box.ItemsSource = textField.Proposals; box.FilterMode = AutoCompleteFilterMode.Contains; box.GotFocus += (sender, args) => { box.IsDropDownOpen = true; }; ```

Original source