/// <summary>
/// Enables auto suggest for the specified text box.
/// </summary>
/// <param name="textBox">The text box.</param>
/// <param name="suggestions">The suggestions.</param>
public static void Enable(TextBox textBox, string[] suggestions)
{
// Try to enable a more advanced settings for AutoComplete via the WinShell interface
try
{
SourceCustomList source = new SourceCustomList {
StringList = suggestions.ToArray()
};
// For options descriptions see:
// https://docs.microsoft.com/en-us/windows/win32/api/shldisp/ne-shldisp-autocompleteoptions
AUTOCOMPLETEOPTIONS options = AUTOCOMPLETEOPTIONS.ACO_UPDOWNKEYDROPSLIST | AUTOCOMPLETEOPTIONS.ACO_USETAB |
AUTOCOMPLETEOPTIONS.ACO_AUTOAPPEND | AUTOCOMPLETEOPTIONS.ACO_AUTOSUGGEST;
Enable(textBox.Handle, source, options);
}
catch (Exception)
{
// In case of an error, let's fall back to the default
AutoCompleteStringCollection source = new AutoCompleteStringCollection();
source.AddRange(suggestions);
textBox.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
textBox.AutoCompleteSource = AutoCompleteSource.CustomSource;
textBox.AutoCompleteCustomSource = source;
}
}
/// <summary>
/// Enables the specified control handle.
/// </summary>
/// <param name="controlHandle">The control handle.</param>
/// <param name="items">The items.</param>
/// <param name="options">The options.</param>
private static void Enable(IntPtr controlHandle, SourceCustomList items, AUTOCOMPLETEOPTIONS options)
{
if (controlHandle == IntPtr.Zero)
{
return;
}
IAutoComplete2?iac = null;
try
{
iac = GetAutoComplete() as IAutoComplete2;
iac?.Init(controlHandle, items, string.Empty, string.Empty);
iac?.SetOptions(options);
iac?.Enable(true);
}
finally
{
if (iac != null)
{
Marshal.ReleaseComObject(iac);
}
}
}