PivotItem control windows phone 7 set color of disabled header

问题

Is there a way to set the state of the header color in XAML when the PivotItem control is not the current selected one.

This is the header code i am using for the pivot item control

<controls:PivotItem.Header>
  <TextBlock Text="first" Foreground="{StaticResource PhoneAccentBrush}"/>
</controls:PivotItem.Header>

In the below example, I want all the header's color to be PhoneAccentBrush but when it goes in the disabled state, I want to it to be grey (but it becomes a dimmed version of PhoneAccentBrush). How to do that ? I know for sure I can do this hack in C# code, but I want this done in the XAML itself. Please help.

回答1:

Unfortunately there is a lot of styling that needs to happen to get this accomplished. First you need to create a style for the Pivot. It is best to do this with Expression Blend.

<Style x:Key="PivotStyle1" TargetType="controls:Pivot">
    <Setter Property="Margin" Value="0"/>
    <Setter Property="Padding" Value="0"/>
    <Setter Property="Foreground" Value="{StaticResource PhoneForegroundBrush}"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="ItemsPanel">
        <Setter.Value>
            <ItemsPanelTemplate>
                <Grid/>
            </ItemsPanelTemplate>
        </Setter.Value>
    </Setter>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="controls:Pivot">
                <Grid HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>
                    <Grid Background="{TemplateBinding Background}" CacheMode="BitmapCache" Grid.RowSpan="3"/>
                    <ContentPresenter ContentTemplate="{TemplateBinding TitleTemplate}" Content="{TemplateBinding Title}" Margin="24,17,0,-7"/>
                    <controlsPrimitives:PivotHeadersControl x:Name="HeadersListElement" Grid.Row="1"/>
                    <ItemsPresenter x:Name="PivotItemPresenter" Margin="{TemplateBinding Padding}" Grid.Row="2"/>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Notice in the style that there is a PivotHeadersControl in it. This control is a TemplatedItemsControl of type PivotHeaderItem. This PivotHeaderItem is what we need to style. You can set the ItemContainerStyle property to alter how the headers will look depending on their state.

<Style x:Key="PivotHeaderItemStyle1" TargetType="controlsPrimitives:PivotHeaderItem">
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Padding" Value="21,0,1,0"/>
    <Setter Property="CacheMode" Value="BitmapCache"/>
    <Setter Property="Margin" Value="0"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="controlsPrimitives:PivotHeaderItem">
                <Grid>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="SelectionStates">
                            <VisualState x:Name="Unselected">
                                <Storyboard>
                                    <ColorAnimation Duration="0" Storyboard.TargetName="contentPresenter" 
                                Storyboard.TargetProperty="(TextBlock.Foreground).(SolidColorBrush.Color)" To="Gray"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Selected">
                                <Storyboard>
                                    <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="contentPresenter"/>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <TextBlock x:Name="contentPresenter" 
                Text="{TemplateBinding Content}"
                HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                Foreground="{StaticResource PhoneAccentBrush}"
                Margin="{TemplateBinding Padding}" Opacity=".4"/>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

I've modified the default style to have a TextBlock instead of a ContentPresenter. This allows you to set the foreground from the Unselected state storyboard.

Make sure that you set the Style of the Pivot to be PivotStyle1 and that the ItemContainerStyle of the PivotHeadersControl is set to PivotHeaderItemStyle1. You'll also need to modify it a little to get the sizing back the way you want it.

来源：https://stackoverflow.com/questions/11746411/pivotitem-control-windows-phone-7-set-color-of-disabled-header