TextBox readonly "on/off" between "double click and lost focus events" in wpf

You can make this with 2 events, MouseDoubleClick and LostFocus

<Grid>    <TextBox IsReadOnly="True"             MouseDoubleClick="TextBox_MouseDoubleClick"             LostFocus="TextBox_LostFocus"/></Grid>

In you procedural code:

private void TextBox_MouseDoubleClick(object sender, MouseButtonEventArgs e){    TextBox textBox = sender as TextBox;    textBox.IsReadOnly = false;    //textBox.CaretIndex = textBox.Text.Count();    textBox.SelectAll();}private void TextBox_LostFocus(object sender, RoutedEventArgs e){    TextBox textBox = sender as TextBox;    textBox.IsReadOnly = true;}

You can use Style and EventTrigger to do that

<Window xmlns:sys="clr-namespace:System;assembly=mscorlib" ...>    <Window.Resource>        <Style x:Key="MyTextBoxStyle" TargetType="{x:Type TextBox}">            <Style.Triggers>                <EventTrigger RoutedEvent="LostFocus">                    <EventTrigger.Actions>                        <BeginStoryboard>                            <Storyboard>                                <ObjectAnimationUsingKeyFrames Duration="0"                                    Storyboard.TargetProperty="(TextBox.IsReadOnly)">                                    <DiscreteObjectKeyFrame KeyTime="0">                                        <DiscreteObjectKeyFrame.Value>                                            <sys:Boolean>True</sys:Boolean>                                        </DiscreteObjectKeyFrame.Value>                                    </DiscreteObjectKeyFrame>                                </ObjectAnimationUsingKeyFrames>                            </Storyboard>                        </BeginStoryboard>                    </EventTrigger.Actions>                </EventTrigger>                <EventTrigger RoutedEvent="MouseDoubleClick">                    <EventTrigger.Actions>                        <BeginStoryboard>                            <Storyboard>                                <ObjectAnimationUsingKeyFrames Duration="0"                                       Storyboard.TargetProperty="(TextBox.IsReadOnly)">                                    <DiscreteObjectKeyFrame KeyTime="0">                                        <DiscreteObjectKeyFrame.Value>                                            <sys:Boolean>False</sys:Boolean>                                        </DiscreteObjectKeyFrame.Value>                                    </DiscreteObjectKeyFrame>                                </ObjectAnimationUsingKeyFrames>                            </Storyboard>                        </BeginStoryboard>                    </EventTrigger.Actions>                </EventTrigger>            </Style.Triggers>        </Style>    </Window.Resource>    ...    <TextBox Style="{StaticResource MyTextBoxStyle}" .../></Window>

You can use System.Windows.Interactivity assembly (msdn) to do that.

First: create helper class to set properties:

public class SetterAction : TriggerAction<DependencyObject>{    public SetterAction()    {        Setters = new List<Setter>();    }    public List<Setter> Setters { get; set; }    protected override void Invoke(object parameter)    {        foreach (var item in Setters)        {            AssociatedObject.SetValue(item.Property, item.Value);        }    }}

XAML:

<TextBox Text="{Binding Name, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"         Background="Transparent" IsReadOnly="True" BorderThickness="0" TextWrapping="Wrap"         Height="30" Width="200">    <i:Interaction.Triggers>        <i:EventTrigger EventName="MouseDoubleClick">            <i:EventTrigger.Actions>                <local:SetterAction>                    <local:SetterAction.Setters>                        <Setter Property="TextBox.IsReadOnly" Value="False" />                        <Setter Property="TextBox.Background" Value="Green" />                    </local:SetterAction.Setters>                </local:SetterAction>            </i:EventTrigger.Actions>        </i:EventTrigger>        <i:EventTrigger EventName="LostFocus">            <i:EventTrigger.Actions>                <local:SetterAction>                    <local:SetterAction.Setters>                        <Setter Property="TextBox.IsReadOnly" Value="True" />                        <Setter Property="TextBox.Background" Value="Red" />                    </local:SetterAction.Setters>                </local:SetterAction>            </i:EventTrigger.Actions>        </i:EventTrigger>    </i:Interaction.Triggers></TextBox>

Where i is:

xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"