How to remove or hide Toolbar item in specific page error: System.IndexOutOfRangeException: Index was outside the bounds of the array

Question

I am trying to Remove() or Clear() ToolbarItems. Here is my code where I am creating ToolbarItem in MainPage.cs

public partial class MainPage : MasterDetailPage
{
   public ToolbarItem cCounter = new ToolbarItem() { Icon = "picture.png" };
   public ToolbarItem pPo = new ToolbarItem() { Text = "-" };

   public MainPage()
    {
        InitializeComponent();
        if (Device.OS == TargetPlatform.iOS)
        {
            provider.Clicked += iOS_Ppo_Clicked;
            ToolbarItems.Add(cCounter);
            ToolbarItems.Add(pPo);
        }
    }

    private void iOS_Ppo_Clicked(object sender, EventArgs e)
    { 
        OpenWindow();            
    }

    public async void OpenWindow()
    {
        if (await Common.WindowComands.CanOpenWindow<PPoPage>(Detail))
        {  
            page = new PPoPage(Page3.Allproviders);

            this.ToolbarItems.Clear(); // here I am getting error:Index was outside the bounds of the array 

            page.OnSelected += Page_OnSelected;
            await Detail.Navigation.PushAsync(page, false);             
        }   
    }
}

Edit: when I included this.ToolbarItems.Clear(); in OpenWindow method which initialise that another page opens and it works! Cleans all toolbar items but unfortunately shows this error:
System.IndexOutOfRangeException: Index was outside the bounds of the array.

This items should disappear only for iOS as you see. Here is my page class where I would like to Remove() these ToolbarItems:

public partial class PPoPage : ContentPage
{
   public MainPage main { get; set; }

   private List<PPo> Pro;

   public PPoPage(List<PPo> po)
   {
      InitializeComponent();
      if (Device.OS == TargetPlatform.iOS)
      {
         Pro = po;
         CreateLayout();
         // HERE I WANT TO REMOVE TOOLBARITEMS FOR THIS PAGE
         this.ToolbarItem.Remove(main.cCounter); // here there is error
         this.ToolbarItems.Clear(); // this also doesn't work, because toolbar items still exist after this initialization.
      }
   }
}

In this class I tried both approaches, but none work. Thank you for answers or suggestions.

score 1 · Answer 1 · edited Apr 13 '17 at 12:40

1

I had task to change visibility of toolbar item and I created base content page with wrapper around ToolbarItems collection. My sample could help you:

sample on git

some "tutorial" that I've posted on CodeReview

edited Apr 13 '17 at 12:40

Community

1
1

answered Sep 06 '16 at 09:56

Yehor Hromadskyi

3,308
1
16
29

score 1 · Accepted Answer · answered Sep 07 '16 at 14:22

First of all I really want to thank for all answers and suggestions I tried to implement both answers on my solution, but unfortunately unsuccessfully. Main reason that I wasn't focusing on class where I am implemented whole iOS toolbar and it was on my iOS project.

On iOS toolbar I just wrote simple if statement:

var currentPage = ((NavigationPage)Element).CurrentPage;
if (currentPage != null && currentPage is ContentPage)
{
    TopViewController.NavigationItem.RightBarButtonItems = new UIBarButtonItem[0];
                return;
}

score 0 · Answer 3 · answered Sep 02 '16 at 15:34

0

The problem here is that PPoPage is a different page instance to MainPage, and thus contains its' own ToolbarItems collection.

Try main.ToolbarItems.Clear() in place of this.ToolbarItems.Clear(), assuming the main property has been initialised, or you can access the top-level current page with Xamarin.Forms.NavigationPage.CurrentPage.

answered Sep 02 '16 at 15:34

Ben Jackson

1,108
6
9

Well, when I do like this main.ToolbarItems.Clear(); I am getting on Main.cs error: System.NullReferenceException: Object reference not set to an instance of an object – BinaryTie Sep 06 '16 at 05:27

How to remove or hide Toolbar item in specific page error: System.IndexOutOfRangeException: Index was outside the bounds of the array

3 Answers3