How to set BindingContext of MasterDetailPage.Master - xamarin

Question

I have a MasterDetailPage.Master and a Login page. After the login I call a WebService that returns a filled class to me, and its working, even the BindingContext is getting the values, but the fields on the Page are empty. How do I set the binding context of the MasterDetailPage.Master if it is rendering before the Login page?
This is for a profile page in the MasterDetailPage.Master, using a WebService to fill the binding. I already tried to call a new instance of the MasterDetailPage on the OnDesappearing of the Login page, but not success.
MainPage.xaml
<?xml version="1.0" encoding="utf-8" ?>
<MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:views="clr-namespace:HCTaNaMao.Views"
x:Class="HCTaNaMao.Views.MainPage">
<MasterDetailPage.Master>
<views:InformacoesUsuario />
</MasterDetailPage.Master>
<MasterDetailPage.Detail>
<NavigationPage>
<NavigationPage.Icon>
<OnPlatform x:TypeArguments="FileImageSource">
<On Platform="iOS" Value="tab_feed.png"/>
</OnPlatform>
</NavigationPage.Icon>
<x:Arguments>
<views:Menu />
</x:Arguments>
</NavigationPage>
</MasterDetailPage.Detail>
</MasterDetailPage>
MasterDetailPage.Master.xaml
<?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="HCTaNaMao.Views.InformacoesUsuario"
Title="Dados do Usuário">
<TabbedPage.Children>
<ContentPage Title="Usuário">
<StackLayout Padding="0,50,0,0">
<Image BackgroundColor="LightGray" HorizontalOptions="Center" Source="HC_logo.png"></Image>
<Frame
OutlineColor="Silver"
VerticalOptions="CenterAndExpand"
HorizontalOptions="Fill"
Margin="15">
<StackLayout
HorizontalOptions="Center"
VerticalOptions="Center">
<Label x:Name="lblNome" Text="{Binding nome}" FontSize="18" HorizontalTextAlignment="Center"></Label>
<BoxView Color="Gray" HeightRequest="1" HorizontalOptions="Fill"/>
<Label x:Name="lblProntuario" Text="{Binding prontuario}" FontSize="18" HorizontalTextAlignment="Center"></Label>
<BoxView Color="Gray" HeightRequest="1" HorizontalOptions="Fill"/>
<Button x:Name="btnEditar" Text="Perfil" TextColor="White" WidthRequest="110"
HorizontalOptions="Center" BackgroundColor="SteelBlue" BorderRadius="20"/>
</StackLayout>
</Frame>
</StackLayout>
</ContentPage>
<ContentPage Title="Perfil">
<Frame
OutlineColor="Silver"
VerticalOptions="CenterAndExpand"
HorizontalOptions="Fill"
Margin="15">
<StackLayout>
<TableView>
<TableRoot>
<TableSection Title="Dados Pessoais">
<EntryCell x:Name="cellNome" Placeholder="Nome"
Text="{Binding nome}" IsEnabled="True"></EntryCell>
<EntryCell Placeholder="Data de Nascimento" x:Name="cellNasc"
Text="{Binding data_nascimento}" IsEnabled="True"></EntryCell>
<EntryCell Placeholder="CPF" Keyboard="Numeric" x:Name="cellCpf"
Text="{Binding cpf}" IsEnabled="True"></EntryCell>
<EntryCell Placeholder="CNS" Keyboard="Numeric" x:Name="cellCns"
Text="{Binding cns}" IsEnabled="True"></EntryCell>
</TableSection>
</TableRoot>
</TableView>
<Button Text="Editar"
IsVisible="False">
</Button>
<Button x:Name="btnSalvar"
Text="Salvar"
IsVisible="True" TextColor="White" WidthRequest="110"
HorizontalOptions="Center" BackgroundColor="SteelBlue" BorderRadius="20"></Button>
</StackLayout>
</Frame>
</ContentPage>
</TabbedPage.Children>
</TabbedPage>
MaterDetailPage.xaml.cs
namespace HCTaNaMao.Views
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class InformacoesUsuario : TabbedPage
{
HCTMWebService service = new HCTMWebService();
HCTMPacienteDTO paciente;
public InformacoesUsuario ()
{
InitializeComponent();
btnEditar.Command = new Command(() => this.CurrentPage = this.Children[1]);
btnSalvar.Command = new Command(() => this.CurrentPage = this.Children[0]);
paciente = service.InformacoesPaciente(Login.seq_cliente);
BindingContext = paciente;
}
}
}
I expect MasterPage fields are filled by the Binding

Answer 1

How do I set the binding context of the MasterDetailPage.Master if it is rendering before the Login page?
About binding context of MasterDetailedPage.Master, I do one sample, you can take a look:
MainPage:
<MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:MasterDetailPageNavigation;assembly=MasterDetailPageNavigation"
x:Class="MasterDetailPageNavigation.MainPage">
<MasterDetailPage.Master>
<local:MasterPage x:Name="masterPage" />
</MasterDetailPage.Master>
<MasterDetailPage.Detail>
<NavigationPage>
<x:Arguments>
<local:ContactsPage />
</x:Arguments>
</NavigationPage>
</MasterDetailPage.Detail>
</MasterDetailPage>
public partial class MainPage : MasterDetailPage
{
public MainPage()
{
InitializeComponent();
masterPage.listView.ItemSelected += OnItemSelected;
if (Device.RuntimePlatform == Device.UWP)
{
MasterBehavior = MasterBehavior.Popover;
}
}
void OnItemSelected(object sender, SelectedItemChangedEventArgs e)
{
var item = e.SelectedItem as MasterPageItem;
if (item != null)
{
Detail = new NavigationPage((Page)Activator.CreateInstance(item.TargetType));
masterPage.listView.SelectedItem = null;
IsPresented = false;
}
}
}
MasterPage:
I don't understand why your masterPage is TabbedPage, I think it should be contentpage,that has Listview to display detailed page title.
<ContentPage
x:Class="MasterDetailPageNavigation.MasterPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="using:MasterDetailPageNavigation"
Title="Personal Organiser"
Padding="0,40,0,0"
IconImageSource="hamburger.png">
<StackLayout>
<ListView
x:Name="listView"
x:FieldModifier="public"
ItemsSource="{Binding items}">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Grid Padding="5,10">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="30" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Image Source="{Binding IconSource}" />
<Label Grid.Column="1" Text="{Binding Title}" />
</Grid>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
public partial class MasterPage : ContentPage
{
public ObservableCollection<MasterPageItem> items { get; set; }
public MasterPage()
{
InitializeComponent();
//load data from service or other.
items = new ObservableCollection<MasterPageItem>()
{
new MasterPageItem(){ Title="Contacts", IconSource="contacts.png",TargetType=typeof(ContactsPage)},
new MasterPageItem(){Title="TodoList",IconSource="todo.png",TargetType=typeof(TodoListPage)},
new MasterPageItem(){Title="Reminders",IconSource="reminders.png",TargetType=typeof(ReminderPage)}
};
this.BindingContext = this;
}
}
About MasterDetailedPage, I suggest you can take a look:
https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/navigation/master-detail-page