如何在Xamarin.Forms中将ToolbarItem设置为左侧？

<ContentPage.ToolbarItems>
    <ToolbarItem Icon="icon.png" Text="左侧按钮" Clicked="OnLeftToolbarItemClicked" Order="Primary" Priority="0" />
</ContentPage.ToolbarItems>

private void OnLeftToolbarItemClicked(object sender, EventArgs e)
{
    // 在这里编写左侧按钮点击后的逻辑
}

<NavigationPage.TitleView>
    <StackLayout Orientation="Horizontal">
        <ToolbarItem Icon="icon.png" Text="左侧按钮" Clicked="OnLeftToolbarItemClicked" Order="Primary" Priority="0" />
        <Label Text="页面标题" HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand" />
    </StackLayout>
</NavigationPage.TitleView>