Comment définir les restrictions d'entrée TextBox?

Question

Comment puis-je restreindre TextBox à n'accepter que des majuscules, ou par exemple des chiffres, ou interdire de mettre un caractère spécial?

Bien sûr, c'est un morceau de gâteau pour attraper l'événement TextInput et gérer le texte ici, mais est-ce la bonne façon de le faire?

Answer 1

J'ai fait cela dans le passé avec un comportement attaché, qui peut être utilisé comme ceci:

<TextBox b:Masking.Mask="^\p{Lu}*$"/>

Le code de comportement ci-joint ressemble à ceci:

/// <summary>
/// Provides masking behavior for any <see cref="TextBox"/>.
/// </summary>
public static class Masking
{
    private static readonly DependencyPropertyKey _maskExpressionPropertyKey = DependencyProperty.RegisterAttachedReadOnly("MaskExpression",
        typeof(Regex),
        typeof(Masking),
        new FrameworkPropertyMetadata());

    /// <summary>
    /// Identifies the <see cref="Mask"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty MaskProperty = DependencyProperty.RegisterAttached("Mask",
        typeof(string),
        typeof(Masking),
        new FrameworkPropertyMetadata(OnMaskChanged));

    /// <summary>
    /// Identifies the <see cref="MaskExpression"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty MaskExpressionProperty = _maskExpressionPropertyKey.DependencyProperty;

    /// <summary>
    /// Gets the mask for a given <see cref="TextBox"/>.
    /// </summary>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask is to be retrieved.
    /// </param>
    /// <returns>
    /// The mask, or <see langword="null"/> if no mask has been set.
    /// </returns>
    public static string GetMask(TextBox textBox)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        return textBox.GetValue(MaskProperty) as string;
    }

    /// <summary>
    /// Sets the mask for a given <see cref="TextBox"/>.
    /// </summary>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask is to be set.
    /// </param>
    /// <param name="mask">
    /// The mask to set, or <see langword="null"/> to remove any existing mask from <paramref name="textBox"/>.
    /// </param>
    public static void SetMask(TextBox textBox, string mask)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        textBox.SetValue(MaskProperty, mask);
    }

    /// <summary>
    /// Gets the mask expression for the <see cref="TextBox"/>.
    /// </summary>
    /// <remarks>
    /// This method can be used to retrieve the actual <see cref="Regex"/> instance created as a result of setting the mask on a <see cref="TextBox"/>.
    /// </remarks>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask expression is to be retrieved.
    /// </param>
    /// <returns>
    /// The mask expression as an instance of <see cref="Regex"/>, or <see langword="null"/> if no mask has been applied to <paramref name="textBox"/>.
    /// </returns>
    public static Regex GetMaskExpression(TextBox textBox)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        } 

        return textBox.GetValue(MaskExpressionProperty) as Regex;
    }

    private static void SetMaskExpression(TextBox textBox, Regex regex)
    {
        textBox.SetValue(_maskExpressionPropertyKey, regex);
    }

    private static void OnMaskChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
    {
        var textBox = dependencyObject as TextBox;
        var mask = e.NewValue as string;
        textBox.PreviewTextInput -= textBox_PreviewTextInput;
        textBox.PreviewKeyDown -= textBox_PreviewKeyDown;
        DataObject.RemovePastingHandler(textBox, Pasting);

        if (mask == null)
        {
            textBox.ClearValue(MaskProperty);
            textBox.ClearValue(MaskExpressionProperty);
        }
        else
        {
            textBox.SetValue(MaskProperty, mask);
            SetMaskExpression(textBox, new Regex(mask, RegexOptions.Compiled | RegexOptions.IgnorePatternWhitespace));
            textBox.PreviewTextInput += textBox_PreviewTextInput;
            textBox.PreviewKeyDown += textBox_PreviewKeyDown;
            DataObject.AddPastingHandler(textBox, Pasting);
        }
    }

    private static void textBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        if (maskExpression == null)
        {
            return;
        }

        var proposedText = GetProposedText(textBox, e.Text);

        if (!maskExpression.IsMatch(proposedText))
        {
            e.Handled = true;
        }
    }

    private static void textBox_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        if (maskExpression == null)
        {
            return;
        }

        //pressing space doesn't raise PreviewTextInput - no idea why, but we need to handle
        //explicitly here
        if (e.Key == Key.Space)
        {
            var proposedText = GetProposedText(textBox, " ");

            if (!maskExpression.IsMatch(proposedText))
            {
                e.Handled = true;
            }
        }
    }

    private static void Pasting(object sender, DataObjectPastingEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        if (maskExpression == null)
        {
            return;
        }

        if (e.DataObject.GetDataPresent(typeof(string)))
        {
            var pastedText = e.DataObject.GetData(typeof(string)) as string;
            var proposedText = GetProposedText(textBox, pastedText);

            if (!maskExpression.IsMatch(proposedText))
            {
                e.CancelCommand();
            }
        }
        else
        {
            e.CancelCommand();
        }
    }

    private static string GetProposedText(TextBox textBox, string newText)
    {
        var text = textBox.Text;

        if (textBox.SelectionStart != -1)
        {
            text = text.Remove(textBox.SelectionStart, textBox.SelectionLength);
        }

        text = text.Insert(textBox.CaretIndex, newText);

        return text;
    }
}

Answer 2

J'ai amélioré la réponse de Kent Boogaart en gérant également les actions suivantes qui, auparavant, pouvaient entraîner la violation du modèle:

• Backspace
• Sélectionner et faire glisser le texte d'une manière qui peut violer le motif
• Commande de coupe

Par exemple, la réponse de Kent Boogaart a permis à l'utilisateur d'entrer "ac" en entrant d'abord "abc" et ensuite de supprimer le "b" avec le retour arrière qui viole l'expression régulière suivante

^(a|ab|abc)$

Utilisation (inchangée):

<TextBox b:Masking.Mask="^\p{Lu}*$"/>

Classe de masque:

public static class Masking
{
    private static readonly DependencyPropertyKey _maskExpressionPropertyKey = DependencyProperty.RegisterAttachedReadOnly("MaskExpression",
            typeof(Regex),
            typeof(Masking),
            new FrameworkPropertyMetadata());

    /// <summary>
    /// Identifies the <see cref="Mask"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty MaskProperty = DependencyProperty.RegisterAttached("Mask",
            typeof(string),
            typeof(Masking),
            new FrameworkPropertyMetadata(OnMaskChanged));

    /// <summary>
    /// Identifies the <see cref="MaskExpression"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty MaskExpressionProperty = _maskExpressionPropertyKey.DependencyProperty;

    /// <summary>
    /// Gets the mask for a given <see cref="TextBox"/>.
    /// </summary>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask is to be retrieved.
    /// </param>
    /// <returns>
    /// The mask, or <see langword="null"/> if no mask has been set.
    /// </returns>
    public static string GetMask(TextBox textBox)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        return textBox.GetValue(MaskProperty) as string;
    }

    /// <summary>
    /// Sets the mask for a given <see cref="TextBox"/>.
    /// </summary>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask is to be set.
    /// </param>
    /// <param name="mask">
    /// The mask to set, or <see langword="null"/> to remove any existing mask from <paramref name="textBox"/>.
    /// </param>
    public static void SetMask(TextBox textBox, string mask)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        textBox.SetValue(MaskProperty, mask);
    }

    /// <summary>
    /// Gets the mask expression for the <see cref="TextBox"/>.
    /// </summary>
    /// <remarks>
    /// This method can be used to retrieve the actual <see cref="Regex"/> instance created as a result of setting the mask on a <see cref="TextBox"/>.
    /// </remarks>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask expression is to be retrieved.
    /// </param>
    /// <returns>
    /// The mask expression as an instance of <see cref="Regex"/>, or <see langword="null"/> if no mask has been applied to <paramref name="textBox"/>.
    /// </returns>
    public static Regex GetMaskExpression(TextBox textBox)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        return textBox.GetValue(MaskExpressionProperty) as Regex;
    }

    private static void SetMaskExpression(TextBox textBox, Regex regex)
    {
        textBox.SetValue(_maskExpressionPropertyKey, regex);
    }

    private static void OnMaskChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
    {
        var textBox = dependencyObject as TextBox;
        var mask = e.NewValue as string;
        textBox.PreviewTextInput -= textBox_PreviewTextInput;
        textBox.PreviewKeyDown -= textBox_PreviewKeyDown;
        DataObject.RemovePastingHandler(textBox, Pasting);
        DataObject.RemoveCopyingHandler(textBox, NoDragCopy);
        CommandManager.RemovePreviewExecutedHandler(textBox, NoCutting);


        if (mask == null)
        {
            textBox.ClearValue(MaskProperty);
            textBox.ClearValue(MaskExpressionProperty);
        }
        else
        {
            textBox.SetValue(MaskProperty, mask);
            SetMaskExpression(textBox, new Regex(mask, RegexOptions.Compiled | RegexOptions.IgnorePatternWhitespace));
            textBox.PreviewTextInput += textBox_PreviewTextInput;
            textBox.PreviewKeyDown += textBox_PreviewKeyDown;
            DataObject.AddPastingHandler(textBox, Pasting);
            DataObject.AddCopyingHandler(textBox, NoDragCopy);
            CommandManager.AddPreviewExecutedHandler(textBox, NoCutting);
        }
    }

    private static void NoCutting(object sender, ExecutedRoutedEventArgs e)
    {
        if(e.Command == ApplicationCommands.Cut)
        {
            e.Handled = true;
        }
    }

    private static void NoDragCopy(object sender, DataObjectCopyingEventArgs e)
    {
        if (e.IsDragDrop)
        {
            e.CancelCommand();
        }
    }

    private static void textBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        if (maskExpression == null)
        {
            return;
        }

        var proposedText = GetProposedText(textBox, e.Text);

        if (!maskExpression.IsMatch(proposedText))
        {
            e.Handled = true;
        }
    }

    private static void textBox_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        if (maskExpression == null)
        {
            return;
        }

        string proposedText = null;

        //pressing space doesn't raise PreviewTextInput, reasons here http://social.msdn.Microsoft.com/Forums/en-US/wpf/thread/446ec083-04c8-43f2-89dc-1e2521a31f6b?prof=required
        if (e.Key == Key.Space)
        {
            proposedText = GetProposedText(textBox, " ");
        }
        // Same story with backspace
        else if(e.Key == Key.Back)
        {
            proposedText = GetProposedTextBackspace(textBox);
        }

        if (proposedText != null && proposedText != string.Empty && !maskExpression.IsMatch(proposedText))
        {
            e.Handled = true;
        }

    }

    private static void Pasting(object sender, DataObjectPastingEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        if (maskExpression == null)
        {
            return;
        }

        if (e.DataObject.GetDataPresent(typeof(string)))
        {
            var pastedText = e.DataObject.GetData(typeof(string)) as string;
            var proposedText = GetProposedText(textBox, pastedText);

            if (!maskExpression.IsMatch(proposedText))
            {
                e.CancelCommand();
            }
        }
        else
        {
            e.CancelCommand();
        }
    }

    private static string GetProposedTextBackspace(TextBox textBox)
    {
        var text = GetTextWithSelectionRemoved(textBox);
        if (textBox.SelectionStart > 0 && textBox.SelectionLength == 0)
        {
            text = text.Remove(textBox.SelectionStart-1, 1);
        }

        return text;
    }


    private static string GetProposedText(TextBox textBox, string newText)
    {
        var text = GetTextWithSelectionRemoved(textBox);
        text = text.Insert(textBox.CaretIndex, newText);

        return text;
    }

    private static string GetTextWithSelectionRemoved(TextBox textBox)
    {
        var text = textBox.Text;

        if (textBox.SelectionStart != -1)
        {
            text = text.Remove(textBox.SelectionStart, textBox.SelectionLength);
        }
        return text;
    }
}

Answer 3

J'ai changé le code de VitalyB pour prendre en charge les thèmes de couleurs. Au lieu de bloquer l'entrée utilisateur si elle ne respecte pas le script RegEx, elle met simplement en surbrillance la zone de texte. La zone de texte sera le thème par défaut sans interaction, puis par défaut en vert clair ou en rouge selon la valeur après la définition de l'entrée. Vous pouvez également définir les couleurs d'échec et de réussite par programmation avec:

b:ColorMasking.PassColor = "Hexadecimal Value"
b:ColorMasking.FailColor = "Hexadecimal Value"

La classe est ci-dessous:

public class ColorMasking : DependencyObject
{
    private static readonly DependencyPropertyKey _maskExpressionPropertyKey = DependencyProperty.RegisterAttachedReadOnly("MaskExpression",
            typeof(Regex),
            typeof(ColorMasking),
            new FrameworkPropertyMetadata());

    /// <summary>
    /// Identifies the <see cref="Mask"/> dependency property.
    /// </summary>
    /// 
    public static readonly DependencyProperty PassColorProperty = DependencyProperty.RegisterAttached("PassColor",
            typeof(string),
            typeof(ColorMasking),
            new PropertyMetadata("#99FF99"));

    public static void SetPassColor(DependencyObject obj, string passColor)
    {
        obj.SetValue(PassColorProperty, passColor);
    }

    public static string GetPassColor(DependencyObject obj)
    {
        return (string)obj.GetValue(PassColorProperty);
    }


    public static readonly DependencyProperty FailColorProperty = DependencyProperty.RegisterAttached("FailColor",
            typeof(string),
            typeof(ColorMasking),
            new PropertyMetadata("#FFCCFF"));

    public static void SetFailColor(DependencyObject obj, string failColor)
    {
        obj.SetValue(FailColorProperty, failColor);
    }

    public static string GetFailColor(DependencyObject obj)
    {
        return (string)obj.GetValue(FailColorProperty);
    }

    public static readonly DependencyProperty MaskProperty = DependencyProperty.RegisterAttached("Mask",
            typeof(string),
            typeof(ColorMasking),
            new FrameworkPropertyMetadata(OnMaskChanged));

    private static void OnPassColorChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
    {
        var textBox = dependencyObject as TextBox;
        var color = e.NewValue as string;
        textBox.SetValue(PassColorProperty, color);
    }

    /// <summary>
    /// Identifies the <see cref="MaskExpression"/> dependency property.
    /// </summary>
    public static readonly DependencyProperty MaskExpressionProperty = _maskExpressionPropertyKey.DependencyProperty;

    /// <summary>
    /// Gets the mask for a given <see cref="TextBox"/>.
    /// </summary>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask is to be retrieved.
    /// </param>
    /// <returns>
    /// The mask, or <see langword="null"/> if no mask has been set.
    /// </returns>
    public static string GetMask(TextBox textBox)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        return textBox.GetValue(MaskProperty) as string;
    }

    /// <summary>
    /// Sets the mask for a given <see cref="TextBox"/>.
    /// </summary>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask is to be set.
    /// </param>
    /// <param name="mask">
    /// The mask to set, or <see langword="null"/> to remove any existing mask from <paramref name="textBox"/>.
    /// </param>
    public static void SetMask(TextBox textBox, string mask)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        textBox.SetValue(MaskProperty, mask);
    }

    /// <summary>
    /// Gets the mask expression for the <see cref="TextBox"/>.
    /// </summary>
    /// <remarks>
    /// This method can be used to retrieve the actual <see cref="Regex"/> instance created as a result of setting the mask on a <see cref="TextBox"/>.
    /// </remarks>
    /// <param name="textBox">
    /// The <see cref="TextBox"/> whose mask expression is to be retrieved.
    /// </param>
    /// <returns>
    /// The mask expression as an instance of <see cref="Regex"/>, or <see langword="null"/> if no mask has been applied to <paramref name="textBox"/>.
    /// </returns>
    public static Regex GetMaskExpression(TextBox textBox)
    {
        if (textBox == null)
        {
            throw new ArgumentNullException("textBox");
        }

        return textBox.GetValue(MaskExpressionProperty) as Regex;
    }

    private static void SetMaskExpression(TextBox textBox, Regex regex)
    {
        textBox.SetValue(_maskExpressionPropertyKey, regex);
    }

    private static void OnMaskChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
    {
        var textBox = dependencyObject as TextBox;
        var mask = e.NewValue as string;
        textBox.PreviewTextInput -= textBox_PreviewTextInput;
        textBox.PreviewKeyDown -= textBox_PreviewKeyDown;
        DataObject.RemovePastingHandler(textBox, Pasting);
        DataObject.RemoveCopyingHandler(textBox, NoDragCopy);
        CommandManager.RemovePreviewExecutedHandler(textBox, NoCutting);

        if (mask == null)
        {
            textBox.ClearValue(MaskProperty);
            textBox.ClearValue(MaskExpressionProperty);
        }
        else
        {
            textBox.SetValue(MaskProperty, mask);
            SetMaskExpression(textBox, new Regex(mask, RegexOptions.Compiled | RegexOptions.IgnorePatternWhitespace));
            textBox.PreviewTextInput += textBox_PreviewTextInput;
            textBox.PreviewKeyDown += textBox_PreviewKeyDown;
            DataObject.AddPastingHandler(textBox, Pasting);
            DataObject.AddCopyingHandler(textBox, NoDragCopy);
            CommandManager.AddPreviewExecutedHandler(textBox, NoCutting);
        }
    }

    private static void NoCutting(object sender, ExecutedRoutedEventArgs e)
    {
        if (e.Command == ApplicationCommands.Cut)
        {
            e.Handled = true;
        }
    }

    private static void NoDragCopy(object sender, DataObjectCopyingEventArgs e)
    {
        if (e.IsDragDrop)
        {
            e.CancelCommand();
        }
    }

    private static void textBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        string passHex = (string)textBox.GetValue(PassColorProperty);
        string failHex = (string)textBox.GetValue(FailColorProperty);
        Color passColor = Extensions.ToColorFromHex(passHex);
        Color failColor = Extensions.ToColorFromHex(failHex);

        if (maskExpression == null)
        {
            return;
        }

        var proposedText = GetProposedText(textBox, e.Text);

        if (!maskExpression.IsMatch(proposedText))
        {
            textBox.Background = new SolidColorBrush(failColor);
        }
        else
        {
            textBox.Background = new SolidColorBrush(passColor);
        }
    }

    private static void textBox_PreviewKeyDown(object sender, KeyEventArgs e)
    {
        var textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        string passHex = (string)textBox.GetValue(PassColorProperty);
        string failHex = (string)textBox.GetValue(FailColorProperty);
        Color passColor = Extensions.ToColorFromHex(passHex);
        Color failColor = Extensions.ToColorFromHex(failHex);

        if (maskExpression == null)
        {
            return;
        }

        string proposedText = null;

        //pressing space doesn't raise PreviewTextInput, reasons here http://social.msdn.Microsoft.com/Forums/en-US/wpf/thread/446ec083-04c8-43f2-89dc-1e2521a31f6b?prof=required
        if (e.Key == Key.Space)
        {
            proposedText = GetProposedText(textBox, " ");
        }
        // Same story with backspace
        else if (e.Key == Key.Back)
        {
            proposedText = GetProposedTextBackspace(textBox);
        }

        if (proposedText != null && !maskExpression.IsMatch(proposedText))
        {
            textBox.Background = new SolidColorBrush(failColor);
        }
        else
        {
            textBox.Background = new SolidColorBrush(passColor);
        }

    }

    private static void Pasting(object sender, DataObjectPastingEventArgs e)
    {
        TextBox textBox = sender as TextBox;
        var maskExpression = GetMaskExpression(textBox);

        string passHex = (string)textBox.GetValue(PassColorProperty);
        string failHex = (string)textBox.GetValue(FailColorProperty);
        Color passColor = Extensions.ToColorFromHex(passHex);
        Color failColor = Extensions.ToColorFromHex(failHex);

        if (maskExpression == null)
        {
            return;
        }

        if (e.DataObject.GetDataPresent(typeof(string)))
        {
            var pastedText = e.DataObject.GetData(typeof(string)) as string;
            var proposedText = GetProposedText(textBox, pastedText);

            if (!maskExpression.IsMatch(proposedText))
            {
                textBox.Background = new SolidColorBrush(failColor);
            }
            else
            {
                textBox.Background = new SolidColorBrush(passColor);
            }
        }
        else
        {
            textBox.Background = new SolidColorBrush(failColor);
        }
    }

    private static string GetProposedTextBackspace(TextBox textBox)
    {
        var text = GetTextWithSelectionRemoved(textBox);
        if (textBox.SelectionStart > 0)
        {
            text = text.Remove(textBox.SelectionStart - 1, 1);
        }

        return text;
    }


    private static string GetProposedText(TextBox textBox, string newText)
    {
        var text = GetTextWithSelectionRemoved(textBox);
        text = text.Insert(textBox.CaretIndex, newText);

        return text;
    }

    private static string GetTextWithSelectionRemoved(TextBox textBox)
    {
        var text = textBox.Text;

        if (textBox.SelectionStart != -1)
        {
            text = text.Remove(textBox.SelectionStart, textBox.SelectionLength);
        }
        return text;
    }
}

Pour s'exécuter, le script nécessite une classe écrite par Aaron C, expliquée ici: Silverlight/WPF définit l'ellipse avec une couleur hexadécimale affiché ici: http://www.wiredprairie.us/blog/ index.php/archives/659

Le code est ci-dessous au cas où le site Web serait déplacé:

public static class Extensions
{
    public static void SetFromHex(this Color c, string hex)
    {
        Color c1 = ToColorFromHex(hex);

        c.A = c1.A;
        c.R = c1.R;
        c.G = c1.G;
        c.B = c1.B;
    }

    public static Color ToColorFromHex(string hex)
    {
        if (string.IsNullOrEmpty(hex))
        {
            throw new ArgumentNullException("hex");
        }

        // remove any "#" characters
        while (hex.StartsWith("#"))
        {
            hex = hex.Substring(1);
        }

        int num = 0;
        // get the number out of the string
        if (!Int32.TryParse(hex, System.Globalization.NumberStyles.HexNumber, null, out num))
        {
            throw new ArgumentException("Color not in a recognized Hex format.");
        }

        int[] pieces = new int[4];
        if (hex.Length > 7)
        {
            pieces[0] = ((num >> 24) & 0x000000ff);
            pieces[1] = ((num >> 16) & 0x000000ff);
            pieces[2] = ((num >> 8) & 0x000000ff);
            pieces[3] = (num & 0x000000ff);
        }
        else if (hex.Length > 5)
        {
            pieces[0] = 255;
            pieces[1] = ((num >> 16) & 0x000000ff);
            pieces[2] = ((num >> 8) & 0x000000ff);
            pieces[3] = (num & 0x000000ff);
        }
        else if (hex.Length == 3)
        {
            pieces[0] = 255;
            pieces[1] = ((num >> 8) & 0x0000000f);
            pieces[1] += pieces[1] * 16;
            pieces[2] = ((num >> 4) & 0x000000f);
            pieces[2] += pieces[2] * 16;
            pieces[3] = (num & 0x000000f);
            pieces[3] += pieces[3] * 16;
        }
        return Color.FromArgb((byte)pieces[0], (byte)pieces[1], (byte)pieces[2], (byte)pieces[3]);
    }

}

Answer 4

private void TextBox1_SelectionChanged(object sender, RoutedEventArgs e)
{
    string txt = TextBox1.Text;
    if (txt != "")
    {
        TextBox1.Text = Regex.Replace(TextBox1.Text, "[^0-9]", "");
        if (txt != TextBox1.Text)
        {
            TextBox1.Select(TextBox1.Text.Length, 0);
        }
    }
}

Answer 5

Voici encore une autre version des solutions existantes ici. Il s'agit d'un comportement simulant un événement "TextChanging" fournissant l'ancien texte, le nouveau texte et un indicateur pour annuler la modification. De cette façon, nous pouvons implémenter le filtre que nous voulons.

Je me suis débarrassé du gestionnaire "PreviewKeyDown" utilisé uniquement pour le caractère espace. TextBox semble tout gérer avec des commandes routées et "Space" a sa propre commande, bien qu'elle ne soit pas publique. J'ai également ajouté la prise en charge de raccourcis clavier supplémentaires tels que "Ctrl + Retour arrière" (supprimer le mot précédent).

public class TextChangingBehavior : Behavior<TextBox>
{
    public event EventHandler<TextChangingEventArgs> TextChanging;

    protected override void OnAttached()
    {
        base.OnAttached();

        AssociatedObject.PreviewTextInput += OnPreviewTextInput;
        CommandManager.AddPreviewExecutedHandler(AssociatedObject, OnPreviewExecutedHandler);
        DataObject.AddCopyingHandler(AssociatedObject, OnCopying);
        DataObject.AddPastingHandler(AssociatedObject, OnPasting);
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();

        AssociatedObject.PreviewTextInput -= OnPreviewTextInput;
        CommandManager.RemovePreviewExecutedHandler(AssociatedObject, OnPreviewExecutedHandler);
        DataObject.RemoveCopyingHandler(AssociatedObject, OnCopying);
        DataObject.RemovePastingHandler(AssociatedObject, OnPasting);
    }

    #region Text

    private enum CharCategory
    {
        LetterOrDigit,
        Whitespace,
        Other
    }

    private CharCategory GetCharCategory(char c)
    {
        if (char.IsLetterOrDigit(c))
            return CharCategory.LetterOrDigit;
        else if (char.IsWhiteSpace(c))
            return CharCategory.Whitespace;
        else
            return CharCategory.Other;
    }

    private string GetText(string input = null)
    {
        var box = AssociatedObject;
        var text = box.Text ?? string.Empty;
        if (input != null)
        {
            // Delete selection
            var deleteCount = box.SelectionLength;
            if (deleteCount > 0)
                text = text.Remove(box.SelectionStart, deleteCount);
            // Insert input
            if (input.Length > 0)
                text = text.Insert(box.CaretIndex, input);
        }
        return text;
    }

    #endregion

    private void OnPreviewExecutedHandler(object sender, ExecutedRoutedEventArgs e)
    {
        var box = AssociatedObject;
        var selectionExists = box.SelectionLength > 0;
        var caretIndex = box.CaretIndex;
        string newText = null;

        if (e.Command == ApplicationCommands.Cut)
        {
            if (selectionExists)
                newText = GetText(string.Empty);
        }
        else if (e.Command == EditingCommands.Backspace)
        {
            if (selectionExists)
                newText = GetText(string.Empty);
            else if (caretIndex > 0)
                newText = GetText().Remove(caretIndex - 1, 1);
        }
        else if (e.Command == EditingCommands.Delete)
        {
            if (selectionExists)
                newText = GetText(string.Empty);
            else
            {
                newText = GetText();
                if (caretIndex >= newText.Length)
                    newText = null;
                else
                    newText = newText.Remove(caretIndex, 1);
            }
        }
        else if (e.Command == EditingCommands.DeletePreviousWord)
        {
            if (selectionExists)
                newText = GetText(string.Empty);
            else if (caretIndex > 0)
            {
                newText = GetText();
                var startIndex = caretIndex;
                // Include whitespaces
                do
                    startIndex--;
                while (startIndex > 0 && char.IsWhiteSpace(newText[startIndex]));
                // Include the next block
                var currentCategory = GetCharCategory(newText[startIndex]);
                while (startIndex > 0 && GetCharCategory(newText[startIndex - 1]) == currentCategory)
                    startIndex--;

                newText = newText.Remove(startIndex, caretIndex - startIndex);
            }
        }
        else if (e.Command == EditingCommands.DeleteNextWord)
        {
            if (selectionExists)
                newText = GetText(string.Empty);
            else
            {
                newText = GetText();
                if (caretIndex >= newText.Length)
                    newText = null;
                else
                {
                    var endIndex = caretIndex + 1;
                    // Include the current block
                    var currentCategory = GetCharCategory(newText[caretIndex]);
                    while (endIndex < newText.Length && GetCharCategory(newText[endIndex]) == currentCategory)
                        endIndex++;
                    // Include whitespaces
                    while (endIndex < newText.Length && char.IsWhiteSpace(newText[endIndex]))
                        endIndex++;

                    newText = newText.Remove(caretIndex, endIndex - caretIndex);
                }
            }
        }
        else if (e.Command is RoutedUICommand cmd && new[] { "Space", "ShiftSpace" }.Contains(cmd.Name))
        {
            newText = GetText(" ");
        }

        if (newText != null && OnProcessChange(newText))
            e.Handled = true;
    }

    private void OnCopying(object sender, DataObjectCopyingEventArgs e)
    {
        if (e.IsDragDrop)
        {
            if (OnProcessChange(GetText(string.Empty)))
                e.CancelCommand();
        }
    }

    private void OnPasting(object sender, DataObjectPastingEventArgs e)
    {
        if (e.DataObject.GetDataPresent(typeof(string)))
        {
            if (OnProcessChange(GetText((string)e.DataObject.GetData(typeof(string)))))
                e.CancelCommand();
        }
    }

    private void OnPreviewTextInput(object sender, TextCompositionEventArgs e)
    {
        if (!string.IsNullOrEmpty(e.Text))
        {
            if (OnProcessChange(GetText(e.Text)))
                e.Handled = true;
        }
    }

    private bool OnProcessChange(string newValue)
    {
        var oldValue = GetText();

        if (string.Equals(oldValue, newValue, StringComparison.Ordinal))
            return false;
        else
        {
            var args = new TextChangingEventArgs(oldValue, newValue);
            OnTextChanging(args);
            return args.Cancel;
        }
    }

    protected virtual void OnTextChanging(TextChangingEventArgs e)
    {
        TextChanging?.Invoke(this, e);
    }
}

public class TextChangingEventArgs : EventArgs
{
    public string OldValue { get; }

    public string NewValue { get; }

    public bool Cancel { get; set; }

    public TextChangingEventArgs(string oldValue, string newValue)
    {
        OldValue = oldValue;
        NewValue = newValue;
    }
}