UWP ListView not data - xaml

Question

I have a ListView defined like this:
<ListView x:Name="phonesListView"
Grid.Row="5"
Background="Black"
IsItemClickEnabled="True"
Foreground="Gray" >
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListViewItem">
<Grid>
<Border x:Name="myback" Background="Transparent">
<ContentPresenter Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}" Margin="20, 0, 20, 0"/>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ListView.ItemContainerStyle>
<ListView.ItemTemplate>
<DataTemplate>
<Grid Width="auto" HorizontalAlignment="Stretch">
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid
Grid.Row="0">
<Grid.ColumnDefinitions >
<ColumnDefinition Width="3*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<ComboBox
Grid.Column="0"
VerticalAlignment="Center"
Background="Black"
Foreground="White" >
<ComboBoxItem Content="Home" IsSelected="True"/>
<ComboBoxItem Content="Work"/>
<ComboBoxItem Content="Office"/>
<ComboBoxItem Content="Fax"/>
<ComboBoxItem Content="School"/>
</ComboBox>
<Button
Grid.Column="1"
Height="30"
Width="30"
Foreground="Black"
Margin="0, 5, 0, 5"
HorizontalAlignment="Center" Click="RemovePhone">
<Button.Background>
<ImageBrush Stretch="Fill" ImageSource="Assets/appbar.close.png" />
</Button.Background>
</Button>
</Grid>
<TextBox
Grid.Row="1"
Background="White"
Foreground="Black"
FontSize="18"
Text="{Binding Number}"
InputScope="TelephoneNumber" />
</Grid>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
In code i have attribute:
ObservableCollection<Phone> phones = new ObservableCollection<Phone>();
Everything works fine, I can add and delete items in list view by either
phones.Add or phones.Remove
The problem is for when I'm leaving a page or Save button is pressed the count of this collections is exactly it is supposed to be but there are no data i have filled in input field. Could you help me with that? Thanks.

Answer 1

If you want that the edited data in your ListView flows back to the items so you can save the edits, you'll have to use 2-way binding. When the control (in the sample below your TextBox) loses focus, the value of Text property gets stored back into the bound field (in your sample Number).
<TextBox
Grid.Row="1"
Background="White"
Foreground="Black"
FontSize="18"
Text="{Binding Number, Mode=TwoWay}"
InputScope="TelephoneNumber" />
For more details about binding, read the MSDN article.