Xamarin.Forms iOS应用程序中的工具栏项目字体颜色

<ContentPage.ToolbarItems>
    <ToolbarItem Text="Item 1" Order="Primary" Priority="0" Icon="item1.png" >
        <ToolbarItem.TextColor>
            <OnPlatform x:TypeArguments="Color">
                <On Platform="iOS" Value="Red" />
            </OnPlatform>
        </ToolbarItem.TextColor>
    </ToolbarItem>
</ContentPage.ToolbarItems>

var item = new ToolbarItem
{
    Text = "Item 1",
    Order = ToolbarItemOrder.Primary,
    Priority = 0,
    Icon = "item1.png"
};

item.SetBinding(ToolbarItem.TextColorProperty, new Binding
{
    Path = "ToolbarItemTextColor",
    Source = this,
    Converter = new ColorConverter()
});

ToolbarItems.Add(item);