I cannot apply a custom style for an AppBarButton inside a CommandBar in WP 8.1

问题

I have a very specific question. I could not find any answers for this exact problem, so I used the trial and error method to pinpoint the problem. Here is an example code I have the problem with:

<Page.BottomAppBar>
    <CommandBar x:Name="MainMenuCommandBar" ClosedDisplayMode="Minimal">
        <CommandBar.PrimaryCommands>
            <AppBarButton x:Name="otherCommandButton" Label="Egyéb" Icon="List" Click="otherCommandButton_Click" Style="{StaticResource appbarButton}">
                <AppBarButton.Flyout>
                    <MenuFlyout>
                        <MenuFlyoutItem x:Name="SecondaryFlyout1" Text="Névjegy" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout2" Text="Adatbázis mentés" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout3" Text="Adatbázis visszaállítás" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout4" Text="Terminál törlése" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout5" Text="Jelszavas védelem" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout6" Text="Nyelv váltás" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout7" Text="Betűméret" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                        <MenuFlyoutItem x:Name="SecondaryFlyout8" Text="Kilépés" Style="{StaticResource BottomAppBarFlyoutStyle}"/>
                    </MenuFlyout>
                </AppBarButton.Flyout>
            </AppBarButton>
            <AppBarButton x:Name="refreshCommandButton" Label="Frissítés(Bank)" Icon="Refresh" Style="{StaticResource appbarButton}"/>
            <AppBarButton x:Name="syncCommandButton" Label="Szinkronizál(PC)" Icon="Sync" Style="{StaticResource appbarButton}"/>
        </CommandBar.PrimaryCommands>
    </CommandBar>
</Page.BottomAppBar>

I wanted to apply a custom style for the appbarbuttons inside a commandbar, because the text in the Labels are too long, and I can't see the whole text. So I thought, I will make the text smaller, or the appbarbutton wider. The designer showed me the changes, but when I run the program, nothing changes. The appbarbuttons use the default styling, no matter what I do. So the text don't get smaller when I run the program.

After this, I tried to pinpoint the problem. I tried to edit the template too, but the "edit a copy" command is grayed out. I thought this is weird, because I sweeped through MSDN, and there I saw that the appbarbuttons in fact has a style which I could edit. I copied the default style, made changes, applied it into my app.xaml as a custom style, but I met with the same problem as before. Nothing changed, no matter what I altered in the style. After all these failures, I put an appbarbutton OUTSIDE a commandbar. And at this case, everything works fine. I can edit a copy of the template, and the changes reflect when I run the program. Another weird case is, that the menuflyoutitems can be styled inside the commandbar.

Sorry for the lengthy explanations, I wanted to present what I know already. My question in short that, is there any way to style an appbarbutton inside a commandbar? Or if not, is there any alternative to create a custom commandbar?

回答1:

The CommandBar on Windows Phone is system UI and cannot be customized by the app beyond setting it's foreground and background colors.

If you want to customize the individual buttons you'll need to implement your own panel for them instead of using the app bar. You can place a horizontal Stack Panel at the bottom of your page and include customized AppBarButtons in it. If you want it to shoe and hide you will need to set your own logic to detect the triggering input and then apply an animation to side it open and closed.

来源：https://stackoverflow.com/questions/28607777/i-cannot-apply-a-custom-style-for-an-appbarbutton-inside-a-commandbar-in-wp-8-1