SL - 整理 - 输入更变事件（使即时输入内容能被更新到vm）

方法一：这个只在WPF有效，Silverlight无效

<TextBox Grid.Column="1" Height="26" Margin="0,38,19,0" TextWrapping="Wrap" VerticalAlignment="Top">

                <TextBox.Text>

                    <Binding Path="UserName" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">

                        <Binding.ValidationRules>

                            <vm:UserNameValidationRule></vm:UserNameValidationRule>

                        </Binding.ValidationRules>

                    </Binding>

                </TextBox.Text>

            </TextBox>

---

方法二：Silverlight有效

xmlns

:vmroot="clr-namespace:xxx.xx.ViewModels"

------------------------------------------------------------------------------------------------------------------------

<

TextBox Name="TextBoxSource" AutomationProperties.AutomationId="PA_IssuerViews_IssuerSource_TextBox_TextBoxSource" MaxLength="2000"

vmroot:ContentValidationUtility.ContentValidation="{Binding ElementName=TextBoxSource}"

IsEnabled="{Binding Path=IsEnabledUpdatePanel, Mode=TwoWay}" Margin="300,60,100,0" Height="120" VerticalAlignment="Top" AcceptsReturn="True" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Visible" HorizontalAlignment="Left" Width="500">

<TextBox.Text>

<Binding Path="UpdateObject.Source" Mode="TwoWay">

</Binding>

</TextBox.Text>

</TextBox>

------------------------------------------------------------------------------------------------------------------------

public static class ContentValidationUtility

    {

        /// <summary>

        /// Default button property dependency property

        /// </summary>

        public static readonly DependencyProperty TextBoxProperty

            = DependencyProperty.RegisterAttached("ContentValidation", typeof(TextBox), typeof(ContentValidationUtility),

            new PropertyMetadata(OnContentValidationChanged));

        /// <summary>

        /// Get default button

        /// </summary>

        public static string GetContentValidation(DependencyObject dependencyObject)

        {

            return (string)dependencyObject.GetValue(TextBoxProperty);

        }

        /// <summary>

        /// Set default button

        /// </summary>

        public static void SetContentValidation(DependencyObject dependencyObject, Button value)

        {

            dependencyObject.SetValue(TextBoxProperty, value);

        }

        /// On default button changed

        /// </summary>

        private static void OnContentValidationChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)

        {

            TextBox textbox = sender as TextBox;

            if (textbox != null)

            {

                textbox.TextChanged += new TextChangedEventHandler(textboxTextChanged);

            }

        }

        static void textboxTextChanged(object sender, TextChangedEventArgs e)

        {

            DependencyObject dependency = sender as DependencyObject;

            object textBoxObject = dependency.GetValue(TextBoxProperty);

            if (textBoxObject is TextBox)

            {

                TextBox textBox = textBoxObject as TextBox;

                if (textBox.SelectionStart >= 0)

                {

                    var bindingExpression = textBox.GetBindingExpression(TextBox.TextProperty);

                    if (bindingExpression != null)

                        bindingExpression.UpdateSource();

                }

            }

        }

    }