Toolbar item not showing in xamarin forms

问题:

I am pretty much new to Xamarin forms. I am trying to add toolbar items to content page.

I am using IPAD Air as deployment device and used sever iPhone/ipad simulators as well. I referred the XamarinForms-Mobile App pdf document. Though its a basic, i am not sure, why i am not able to see it in device. Please help me where i am making the mistake.

public partial class SamplePage : ContentPage   
{
    public SamplePage()
    {
        //Toolbar items
            ToolbarItem scanItem = new ToolbarItem ();
            scanItem.Name = "Scan";
            scanItem.Order = ToolbarItemOrder.Primary;

            ToolbarItem settingsItem = new ToolbarItem ();
            settingsItem.Name = "Settings";
            settingsItem.Order = ToolbarItemOrder.Primary;

            ToolbarItems.Add (scanItem);
            ToolbarItems.Add (settingsItem);
    }
}

App.cs

public class App
    {
        public static Page GetMainPage ()
        {   
            return new SamplePage ();
        }
    }

Tried xaml way of doing it as well. But no result. Content page is blank.

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="BLE_Core.BLECorePage">
    <ContentPage.Content>
    </ContentPage.Content>
    <ContentPage.ToolbarItems>
        <ToolbarItem Name = "Scan"></ToolbarItem>
        <ToolbarItem Name = "Settings"></ToolbarItem>
   </ContentPage.ToolbarItems>
</ContentPage>

回答1:

Your ToolbarItems will not show if your app does not have a Toolbar. The simplest way to add one is to wrap your page in a NavigationPage

public static Page GetMainPage ()
{   
  return new NavigationPage(new SamplePage ());
}

回答2:

Just wanted to add an edge case to this which drove me nuts for a couple of hours. I had been adding icons outside of Visual Studio and attempting to reference them as toolbar icons in my Xamarin forms app. When testing the Android app, the toolbar icon I was referencing wouldn't display. I finally figured out that the icons weren't being packaged at all in the .APK file. Why? I'd forgotten to include them in the Visual Studio project. Solution Explorer -> Click on project -> Click on Show All Files icon in header bar of Solution Explorer. Icon files then appear, so just right-click them and select Include in Project for each one. Doh...gnash...gnash etc.