Windows 8開發 ApplicationBar的圖標與對應的Unicode編碼

    首先先來認識一下ApplicationBar中的圖標：

    與WP7的ApplicationBar的圖標樣式很像，但是，他們的實現方式卻是不同的。WP7的ApplicationBar的按鈕圖標來源於固定大小的背景透明的圖片，而在Win8中，盡管也可以按照WP7的方式自定義Button，但是考慮到各種設備的屏幕分辨率不同（WP7開發時主要只需要考慮800*480），用圖片無法完美適配，所以使用了Segoe UI Symbol字體來對特定的Unicode字符進行繪制。

    在Windows 8應用商店APP開發時，新建一個APP默認會在common/StandardStyles.xaml文件內加入各種通用的樣式，其中ApplicationBar的樣式也被包含在內，如下：

<Style x:Key="AppBarButtonStyle" TargetType="Button">
        <Setter Property="Foreground" Value="{StaticResource AppBarItemForegroundThemeBrush}"/>
        <Setter Property="VerticalAlignment" Value="Stretch"/>
        <Setter Property="FontFamily" Value="Segoe UI Symbol"/>
        <Setter Property="FontWeight" Value="Normal"/>
        <Setter Property="FontSize" Value="20"/>
        <Setter Property="AutomationProperties.ItemType" Value="App Bar Button"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Button">
                    <Grid Width="100" Background="Transparent">
                        <StackPanel VerticalAlignment="Top" Margin="0,14,0,13">
                            <Grid Width="40" Height="40" Margin="0,0,0,5" HorizontalAlignment="Center">
                                <TextBlock x:Name="BackgroundGlyph" Text="&#xE0A8;" FontFamily="Segoe UI Symbol" FontSize="53.333" Margin="-4,-19,0,0" Foreground="{StaticResource AppBarItemBackgroundThemeBrush}"/>
                                <TextBlock x:Name="OutlineGlyph" Text="&#xE0A7;" FontFamily="Segoe UI Symbol" FontSize="53.333" Margin="-4,-19,0,0"/>
                                <ContentPresenter x:Name="Content" HorizontalAlignment="Center" Margin="-1,-1,0,0" VerticalAlignment="Center"/>
                            </Grid>
                            <TextBlock
                                x:Name="TextLabel"
                                Text="{TemplateBinding AutomationProperties.Name}"
                                Margin="0,0,2,0"
                                FontSize="12"
                                TextAlignment="Center"
                                Width="88"
                                MaxHeight="32"
                                TextTrimming="WordEllipsis"
                                Style="{StaticResource BasicTextStyle}"/>
                        </StackPanel>
                        <Rectangle
                                x:Name="FocusVisualWhite"
                                IsHitTestVisible="False"
                                Stroke="{StaticResource FocusVisualWhiteStrokeThemeBrush}"
                                StrokeEndLineCap="Square"
                                StrokeDashArray="1,1"
                                Opacity="0"
                                StrokeDashOffset="1.5"/>
                        <Rectangle
                                x:Name="FocusVisualBlack"
                                IsHitTestVisible="False"
                                Stroke="{StaticResource FocusVisualBlackStrokeThemeBrush}"
                                StrokeEndLineCap="Square"
                                StrokeDashArray="1,1"
                                Opacity="0"
                                StrokeDashOffset="0.5"/>

                        <VisualStateManager.VisualStateGroups>
                            <VisualStateGroup x:Name="CommonStates">
                                <VisualState x:Name="Normal"/>
                                <VisualState x:Name="PointerOver">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundGlyph" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemPointerOverBackgroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Content" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemPointerOverForegroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Pressed">
                                    <Storyboard>
                                        <DoubleAnimation
                                            Storyboard.TargetName="OutlineGlyph"
                                            Storyboard.TargetProperty="Opacity"
                                            To="0"
                                            Duration="0"/>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundGlyph" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemForegroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Content" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemPressedForegroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Disabled">
                                    <Storyboard>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="OutlineGlyph" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemDisabledForegroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="Content" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemDisabledForegroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="TextLabel" Storyboard.TargetProperty="Foreground">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource AppBarItemDisabledForegroundThemeBrush}"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualState>
                            </VisualStateGroup>
                            <VisualStateGroup x:Name="FocusStates">
                                <VisualState x:Name="Focused">
                                    <Storyboard>
                                        <DoubleAnimation
                                                Storyboard.TargetName="FocusVisualWhite"
                                                Storyboard.TargetProperty="Opacity"
                                                To="1"
                                                Duration="0"/>
                                        <DoubleAnimation
                                                Storyboard.TargetName="FocusVisualBlack"
                                                Storyboard.TargetProperty="Opacity"
                                                To="1"
                                                Duration="0"/>
                                    </Storyboard>
                                </VisualState>
                                <VisualState x:Name="Unfocused" />
                                <VisualState x:Name="PointerFocused" />
                            </VisualStateGroup>
                        </VisualStateManager.VisualStateGroups>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    可以注意到，在AppBarButtonStyle下面，已經默認創建了一些常用的樣式，每個樣式的區別就是Content的Value的值。

<Style x:Key="DeleteAppBarButtonStyle" TargetType="Button" BasedOn="{StaticResource AppBarButtonStyle}">
        <Setter Property="AutomationProperties.AutomationId" Value="DeleteAppBarButton"/>
        <Setter Property="AutomationProperties.Name" Value="Delete"/>
        <Setter Property="Content" Value="&#xE106;"/>
    </Style>

    觀察一下不難發現，所有的這些Content Value全是Unicode字符串。這些都很簡單。在之前的開發中，我遇到的一個問題就是默認創建的這些Style太少滿足不了整個App的需求，需要一些其他的圖標如傾斜、下划線等等，可是，從哪兒去找這些圖標對應的Unicode編碼呢？
    按快捷鍵Win+R，輸入charmap.exe，打開字符映射表，將字體選擇為Segoe UI Symbol，然后將內容的滾動條滑動到偏下的位置（常用的圖標為E開頭的），如圖，選擇需要的圖標，在窗口左下角就會顯示出該圖標對應的Unicode編碼。

 

 

錦燕雲

微博 http://www.weibo.com/jinyanyun

 http://www.cnblogs.com/vistach/archive/2012/10/24/Windows8_Win8_WinRT_MetroStyleApps_ModernUIApps_ApplicationBar_Icon_SegoeUISymbol.html