I just found an interesting behaviour of Windows Phone 7 TextBox default template. When TextBox is disabled, inner text is rendered with margin:
To reproduce it, create new Silverlight WP application and add following XAML inside default grid named “ContentPanel”:
<StackPanel Margin="0,12,0,0">
<StackPanel.Resources>
<Style TargetType="TextBlock">
<Setter Property="Margin" Value="25,0,25,0"/>
</Style>
<Style TargetType="TextBox">
<Setter Property="Margin" Value="33,0,13,0"/>
</Style>
</StackPanel.Resources>
<TextBlock Text="Name:" />
<TextBox Text="some test text" IsEnabled="False" />
<TextBlock Text="E-mail:"/>
<TextBox Text="test@movaxbx.com" InputScope="EmailNameOrAddress" />
</StackPanel>
The reason is that in disabled state TextBox’s control template is described using another TextBox:
<Border x:Name="EnabledBorder" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" BorderBrush="{TemplateBinding BorderBrush}" Margin="{StaticResource PhoneTouchTargetOverhang}" >
<ContentControl x:Name="ContentElement" BorderThickness="0" Padding="{TemplateBinding Padding}"
HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" Margin="{StaticResource PhoneTextBoxInnerMargin}"/>
</Border>
<Border x:Name="DisabledOrReadonlyBorder" Visibility="Collapsed" Background="Transparent" BorderBrush="{StaticResource PhoneDisabledBrush}" BorderThickness="{TemplateBinding BorderThickness}" Margin="{StaticResource PhoneTouchTargetOverhang}" >
<TextBox x:Name="DisabledOrReadonlyContent" Text="{TemplateBinding Text}" Foreground="{StaticResource PhoneDisabledBrush}" Background="Transparent"
SelectionBackground="{TemplateBinding SelectionBackground}" SelectionForeground="{TemplateBinding SelectionForeground}"
TextWrapping="{TemplateBinding TextWrapping}" TextAlignment="{TemplateBinding TextAlignment}" IsReadOnly="True" Template="{StaticResource PhoneDisabledTextBoxTemplate}"
FontFamily="{TemplateBinding FontFamily}" FontSize="{TemplateBinding FontSize}" FontWeight="{TemplateBinding FontWeight}" FontStyle="{TemplateBinding FontStyle}" />
</Border>
This XAML is a part of TextBox’s default control template (you can get full version with Blend). In case of setting IsEnabled=”False”, EnabledBorder is hidden and DisabledOrReadOnlyBorder is visible. So, textbox rendered using TextBox.
You can notice, that in first code sample style for TextBox without x:Key. It means, that style applied to any of child TextBox. So, margin was applied to control template’s inner TextBox too. And that’s the reason, why we have a shifted text in disabled state!
As a solution: you can add x:Key for TextBox style and apply it manually to every TextBox. In this case disabled state will work normally.
P.S. The same is valid for PasswordBox too.