如何将 xamarin 表单中的选项卡 2 设置为启动时的默认选项卡

Question

I have an app I am working on in xamarin forms it looks like this:

When the app loads the friends tab is the 1st tab to load how do I make it to where the snap tab is the 1st tab to load when the app starts up?

Here is my xaml code:

<?xml version="1.0" encoding="UTF-8"?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
            xmlns:local="clr-namespace:AppName;assembly=AppName"
            x:Class="AppName.HomePage">
    <TabbedPage.Children>
        <NavigationPage x:Name="Friends" Title="Friends" Icon="firendstab.png">
            <x:Arguments>
                <local:FriendPage />
            </x:Arguments>
        </NavigationPage >
        <NavigationPage  x:Name="Snap" Title="Snap" Icon="snaptab.png">>
            <x:Arguments>
                <local:CameraPage />
            </x:Arguments>
        </NavigationPage>
        <NavigationPage x:Name="Notes" Title="Notes" Icon="notetab.png">
            <x:Arguments>
                <local:NotePage />
            </x:Arguments>
        </NavigationPage>
    </TabbedPage.Children>
</TabbedPage>

heres my code behind:

using System;
using System.Collections.Generic;

using Xamarin.Forms;

namespace AppName
{
    public partial class HomePage : TabbedPage
    {
        public HomePage()
        {
            InitializeComponent();






        }
    }
}

I've searched google for the past 2 days so I thought it was time to ask!

Answer 1

You can access the enumerator of the TabbedPage 's children and advance its position two times to get your "second tab". Assign that page as your CurrentPage :

public HomePage()
{
    InitializeComponent();
    var pages = Children.GetEnumerator();
    pages.MoveNext(); // First page
    pages.MoveNext(); // Second page
    CurrentPage = pages.Current;
}

Answer 2

public HomePage()
{
    InitializeComponent();
    CurrentPage = Children[2];
}

Answer 3

I think you have to set "CurrentPage" property.

In code is something like

            TabbedPage tp = new TabbedPage();
            tp.Children.Add(new PageFriends());
            tp.Children.Add(new PageSnap());
            tp.Children.Add(new PageNotes());
            tp.CurrentPage = tp.Children[1];

Answer 4

For me, what I did was this:

  (this.Parent as TabbedPage).CurrentPage = (this.Parent as TabbedPage).Children[2];

because in my tabbed page, I added my pages like this

this.Children.Add(new Landing());
this.Children.Add(new Categories());
this.Children.Add(new Collections());
this.Children.Add(new Options());

The above code snippets, will lead me to the Collections Page.