Esempio n. 1
0
        private static void OnSearchModePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            AutoCompleteTextBox    source = d as AutoCompleteTextBox;
            AutoCompleteSearchMode mode   = (AutoCompleteSearchMode)e.NewValue;

            if (mode != AutoCompleteSearchMode.Contains &&
                mode != AutoCompleteSearchMode.ContainsCaseSensitive &&
                mode != AutoCompleteSearchMode.ContainsOrdinal &&
                mode != AutoCompleteSearchMode.ContainsOrdinalCaseSensitive &&
                mode != AutoCompleteSearchMode.Custom &&
                mode != AutoCompleteSearchMode.Equals &&
                mode != AutoCompleteSearchMode.EqualsCaseSensitive &&
                mode != AutoCompleteSearchMode.EqualsOrdinal &&
                mode != AutoCompleteSearchMode.EqualsOrdinalCaseSensitive &&
                mode != AutoCompleteSearchMode.None &&
                mode != AutoCompleteSearchMode.StartsWith &&
                mode != AutoCompleteSearchMode.StartsWithCaseSensitive &&
                mode != AutoCompleteSearchMode.StartsWithOrdinal &&
                mode != AutoCompleteSearchMode.StartsWithOrdinalCaseSensitive)
            {
                source.SetValue(e.Property, e.OldValue);

                throw new ArgumentException("", "value");
            }

            // Sets the filter predicate for the new value
            AutoCompleteSearchMode newValue = (AutoCompleteSearchMode)e.NewValue;

            source.TextFilter = AutoCompleteSearch.GetFilter(newValue);
        }
Esempio n. 2
0
        /// <summary>
        /// Performs text completion, if enabled, and a lookup on the underlying
        /// item values for an exact match. Will update the SelectedItem value.
        /// </summary>
        /// <param name="userInitiated">A value indicating whether the operation
        /// was user initiated. Text completion will not be performed when not
        /// directly initiated by the user.</param>
        private void UpdateTextCompletion(bool userInitiated)
        {
            // By default this method will clear the selected value
            object newSelectedItem = null;
            string text            = Text;

            // Text search is StartsWith explicit and only when enabled, in
            // line with WPF's ComboBox lookup. When in use it will associate
            // a Value with the Text if it is found in ItemsSource. This is
            // only valid when there is data and the user initiated the action.
            if (View.Count > 0)
            {
                if (IsTextCompletionEnabled && TextBox != null && userInitiated)
                {
                    int currentLength  = TextBox.Text.Length;
                    int selectionStart = TextBox.SelectionStart;
                    if (selectionStart == text.Length && selectionStart > TextSelectionStart)
                    {
                        // When the SearchMode dependency property is set to
                        // either StartsWith or StartsWithCaseSensitive, the
                        // first item in the view is used. This will improve
                        // performance on the lookup. It assumes that the
                        // SearchMode the user has selected is an acceptable
                        // case sensitive matching function for their scenario.
                        object top = SearchMode == AutoCompleteSearchMode.StartsWith || SearchMode == AutoCompleteSearchMode.StartsWithCaseSensitive
                            ? View[0]
                            : TryGetMatch(text, View, AutoCompleteSearch.GetFilter(AutoCompleteSearchMode.StartsWith));

                        // If the search was successful, update SelectedItem
                        if (top != null)
                        {
                            newSelectedItem = top;
                            string topString = FormatValue(top);

                            // Only replace partially when the two words being the same
                            int minLength = Math.Min(topString.Length, Text.Length);
                            if (AutoCompleteSearch.Equals(Text.Substring(0, minLength), topString.Substring(0, minLength)))
                            {
                                // Update the text
                                UpdateTextValue(topString);

                                // Select the text past the user's caret
                                TextBox.SelectionStart  = currentLength;
                                TextBox.SelectionLength = topString.Length - currentLength;
                            }
                        }
                    }
                }
                else
                {
                    // Perform an exact string lookup for the text. This is a
                    // design change from the original Toolkit release when the
                    // IsTextCompletionEnabled property behaved just like the
                    // WPF ComboBox's IsTextSearchEnabled property.
                    //
                    // This change provides the behavior that most people expect
                    // to find: a lookup for the value is always performed.
                    newSelectedItem = TryGetMatch(text, View, AutoCompleteSearch.GetFilter(AutoCompleteSearchMode.EqualsCaseSensitive));
                }
            }

            // Update the selected item property
            SelectedItem = newSelectedItem;

            // Restore updates for TextSelection
            if (IgnoreTextSelectionChange)
            {
                IgnoreTextSelectionChange = false;
                if (TextBox != null)
                {
                    TextSelectionStart = TextBox.SelectionStart;
                }
            }
        }