XAML Data Binding value not refreshing inside two ContentPages - xaml

Question

I am trying to output a value from my object to two different entries. Both entries are on the same view but in different ContentPages as follows:
<?xml version="1.0" encoding="utf-8" ?>
<TabbedPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="myApp.Views.ViewTabs.ViewHome"
xmlns:localTabs="clr-namespace:myApp.Views.ViewTabs"
xmlns:localObjPages="clr-namespace:myApp.Objects"
>
<ContentPage Title="PageOne">
<ContentPage.BindingContext>
<localObjPages:PagesObj/>
</ContentPage.BindingContext>
<ScrollView>
<StackLayout>
<Entry
x:Name="EntryOne" Text="{Binding BananaCount}"/>
<Entry
x:Name="EntryTwo" Text="{Binding BananaCount}"/>
</StackLayout>
</ScrollView>
</ContentPage>
<ContentPage Title="PageTwo">
<ContentPage.BindingContext>
<localObjPages:PagesObj/>
</ContentPage.BindingContext>
<ScrollView>
<StackLayout>
<Entry
x:Name="EntryThree" Text="{Binding BananaCount}"/>
</StackLayout>
</ScrollView>
</ContentPage>
</TabbedPage>
My Model:
public string BananaCount
{
get { return _bananaCount; }
set
{
if (_bananaCount != value)
{
_bananaCount = value;
NotifyPropertyChanged("BananaCount");
}
}
}
The object is updated and returned in EntryOne or in EntryTwo when I change it either in EntryOne or in EntryTwo. However, it is not updated in EntryThree. Why is this? Am I Binding this correctly? Thank you.

Answer 1

The object is updated and returned in EntryOne or in EntryTwo when I change it either in EntryOne or in EntryTwo. However, it is not updated in EntryThree. Why is this? Am I Binding this correctly?
Do one sample about TabbedPage, assign datasource for TabbedPage, not contentpage, that you can take a look:
<TabbedPage
x:Class="FormsSample.tabbedpage.TabbedPage6"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:FormsSample.tabbedpage">
<!--Pages can be added as references or inline-->
<ContentPage Title="PageOne">
<ScrollView>
<StackLayout>
<Entry x:Name="EntryOne" Text="{Binding str}" />
<Entry x:Name="EntryTwo" Text="{Binding str}" />
<Button
x:Name="btn1"
Clicked="btn1_Clicked"
Text="change data" />
</StackLayout>
</ScrollView>
</ContentPage>
<ContentPage Title="PageTwo">
<ScrollView>
<StackLayout>
<Entry x:Name="EntryThree" Text="{Binding str}" />
</StackLayout>
</ScrollView>
</ContentPage>
public partial class TabbedPage6 : TabbedPage
{
public tabclass tabc { get; set; }
public TabbedPage6()
{
InitializeComponent();
tabc = new tabclass();
this.BindingContext = tabc;
}
private void btn1_Clicked(object sender, EventArgs e)
{
tabc.str = "this is test!";
}
}
public class tabclass:ViewModelBase
{
private string _str;
public string str
{
get { return _str; }
set
{
_str = value;
RaisePropertyChanged("str");
}
}
}
The ViewModel is one class that implement INotifyPropertyChanged.
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}