Transparent textbox when textbox GotFocussed Windows Phone 8.1?

Question

I need to have transparent textbox, in my WindowsPhone 8.1 Runtime application.

I made Background="Transparent" to the textbox, so it is transparent when it is loaded.

But on focus, background color changed to white. I write the following code, to make it transparent. But it doesn't run.!

<TextBox Background="Transparent" GotFocus="titleBox_GotFocus" />

C#

private void titleBox_GotFocus(object sender, RoutedEventArgs e)
{
    titleBox.Background = new SolidColorBrush(Colors.Transparent);
}

Answer 1

The problem is that when you the TextBox gets focused, the StoryBoard is changing the Background to ThemeResource - the TExtBox by default is designed to do that. Of course you can change it - as you are targetting WP8.1 Runtime, you will have to play with VisualStaes of your TextBox. To say more, you will have to change Focused state:

<VisualState x:Name="Focused">
    <Storyboard>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
        </ObjectAnimationUsingKeyFrames>
        <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
        </ObjectAnimationUsingKeyFrames>
    </Storyboard>
</VisualState>

In the code above, I've changed the third animation, so now it sets Transparent to Background.

---

The complete Style (taken from Blend) can look like this:

<Page.Resources>
<Style x:Key="TransparentStyle" TargetType="TextBox">
    <Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}"/>
    <Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}"/>
    <Setter Property="Foreground" Value="{ThemeResource TextBoxForegroundThemeBrush}"/>
    <Setter Property="SelectionHighlightColor" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
    <Setter Property="Background" Value="{ThemeResource TextBoxBackgroundThemeBrush}"/>
    <Setter Property="BorderBrush" Value="{ThemeResource TextBoxBorderThemeBrush}"/>
    <Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}"/>
    <Setter Property="FontFamily" Value="{ThemeResource PhoneFontFamilyNormal}"/>
    <Setter Property="FontSize" Value="{ThemeResource ContentControlFontSize}"/>
    <Setter Property="TextWrapping" Value="NoWrap"/>
    <Setter Property="ScrollViewer.HorizontalScrollMode" Value="Auto"/>
    <Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto"/>
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden"/>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden"/>
    <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False"/>
    <Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}"/>
    <Setter Property="Margin" Value="{ThemeResource TextControlMarginThemeThickness}"/>
    <Setter Property="VerticalAlignment" Value="Top"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TextBox">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBackgroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBorderThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Normal">
                                <Storyboard>
                                    <DoubleAnimation Duration="0" To="{ThemeResource TextControlBackgroundThemeOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="BackgroundElement"/>
                                    <DoubleAnimation Duration="0" To="{ThemeResource TextControlBorderThemeOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="BorderElement"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Focused">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Border x:Name="BackgroundElement" Background="{TemplateBinding Background}" Margin="{TemplateBinding BorderThickness}" Grid.Row="1"/>
                    <Border x:Name="BorderElement" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Grid.Row="1"/>
                    <ContentPresenter x:Name="HeaderContentPresenter" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" Margin="{ThemeResource TextControlHeaderMarginThemeThickness}" Grid.Row="0" Style="{StaticResource HeaderContentPresenterStyle}"/>
                    <ScrollViewer x:Name="ContentElement" AutomationProperties.AccessibilityView="Raw" HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsTabStop="False" IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}" IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" Margin="{TemplateBinding BorderThickness}" MinHeight="{ThemeResource TextControlThemeMinHeight}" Padding="{TemplateBinding Padding}" Grid.Row="1" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}" ZoomMode="Disabled"/>
                    <ContentControl x:Name="PlaceholderTextContentPresenter" Content="{TemplateBinding PlaceholderText}" Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}" FontSize="{ThemeResource ContentControlFontSize}" IsTabStop="False" Margin="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}" Grid.Row="1"/>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
</Page.Resources>

And you use it like this:

<TextBox Background="Transparent" GotFocus="titleBox_GotFocus" Style="{StaticResource TransparentStyle}"/>

Answer 2

You can make the Textbox transparent always by applying the following style,

Style:

 <ControlTemplate x:Key="PhoneDisabledTextBoxTemplate" TargetType="TextBox">
        <ContentControl x:Name="ContentElement" BorderThickness="0" HorizontalContentAlignment="Stretch" Margin="{StaticResource PhoneTextBoxInnerMargin}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="Stretch"/>
    </ControlTemplate>
    <Style x:Key="TransparentTextBoxStyle" TargetType="TextBox">
        <Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilyNormal}"/>
        <Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMediumLarge}"/>
        <Setter Property="Background" Value="{StaticResource PhoneTextBoxBrush}"/>
        <Setter Property="Foreground" Value="{StaticResource PhoneTextBoxForegroundBrush}"/>
        <Setter Property="BorderBrush" Value="{StaticResource PhoneTextBoxBrush}"/>
        <Setter Property="SelectionBackground" Value="{StaticResource PhoneAccentBrush}"/>
        <Setter Property="SelectionForeground" Value="{StaticResource PhoneTextBoxSelectionForegroundBrush}"/>
        <Setter Property="BorderThickness" Value="{StaticResource PhoneBorderThickness}"/>
        <Setter Property="Padding" Value="2"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="TextBox">
                    <Grid Background="Transparent">
                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="MouseOver"/>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="EnabledBorder">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Collapsed</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="DisabledOrReadonlyBorder">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="ReadOnly">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="EnabledBorder">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Collapsed</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="DisabledOrReadonlyBorder">
                                            <DiscreteObjectKeyFrame KeyTime="0">
                                                <DiscreteObjectKeyFrame.Value>
                                                    <Visibility>Visible</Visibility>
                                                </DiscreteObjectKeyFrame.Value>
                                            </DiscreteObjectKeyFrame>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="DisabledOrReadonlyContent">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxReadOnlyBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="FocusStates">
                                <VisualState x:Name="Focused"/>
                                <VisualState x:Name="Unfocused"/>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="ValidationStates">
                                <VisualState x:Name="InvalidFocused"/>
                                <VisualState x:Name="Valid"/>
                                <VisualState x:Name="InvalidUnfocused"/>
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                        <Border x:Name="EnabledBorder" BorderThickness="{TemplateBinding BorderThickness}" Margin="{StaticResource PhoneTouchTargetOverhang}">
                            <ContentControl x:Name="ContentElement" BorderThickness="0" HorizontalContentAlignment="Stretch" Margin="{StaticResource PhoneTextBoxInnerMargin}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="Stretch"/>
                        </Border>
                        <Border x:Name="DisabledOrReadonlyBorder" BorderThickness="{TemplateBinding BorderThickness}" Margin="{StaticResource PhoneTouchTargetOverhang}" Visibility="Collapsed">
                            <TextBox x:Name="DisabledOrReadonlyContent" Foreground="{StaticResource PhoneDisabledBrush}" FontWeight="{TemplateBinding FontWeight}" FontStyle="{TemplateBinding FontStyle}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" IsReadOnly="True" SelectionForeground="{TemplateBinding SelectionForeground}" SelectionBackground="{TemplateBinding SelectionBackground}" TextAlignment="{TemplateBinding TextAlignment}" TextWrapping="{TemplateBinding TextWrapping}" Text="{TemplateBinding Text}" Template="{StaticResource PhoneDisabledTextBoxTemplate}"/>
                        </Border>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

XAML:

<TextBox Style="{StaticResource TransparentTextBoxStyle}"/>

Refered from : TRANSPARENT TEXTBOX FOR WINDOWS PHONE