I use MVVM when I update view model programmatically view does not update.
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public virtual void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
my model :
public class Payment:ViewModelBase
{
private long _paymentId;
private decimal _price;
[DatabaseGenerated(DatabaseGeneratedOption.None)]
public long PaymentId {
get { return _paymentId; }
set
{
_paymentId = value;
OnPropertyChanged(nameof(PaymentId));
}
}
public decimal Price {
get { return _price; }
set
{
_price = value;
OnPropertyChanged(nameof(Price));
}
}
}
my view model :
class PaymentFactorViewModel : ViewModelBase
{
public PaymentFactorViewModel()
{
PaymentFactor = new PaymentFactor();
PaymentFactor.Price=350,000;
}
private Payment _paymentFactor;
public Payment PaymentFactor
{
get { return _paymentFactor; }
set
{
_paymentFactor = value;
OnPropertyChanged(nameof(PaymentFactor));
}
}
}
my view :
<TextBox x:Name="txtPrice" Text="{Binding PaymentFactor.Price,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged"/>
when I change TextBox.Text ViewModel will update, but when I change ViewModel programmatically View does not update.
For example I set PaymentFactor.Price=350,000 in ViewModel constructor but TextBox.Text is 0.
There are several mistakes in the code you posted.
PaymentFactorViewmodel should be public
Lose the , in 350000
You don't have a PaymentFactor class, you have Payment. I don't see how that piece of code can even compile.
The below works ok for me. Or at least it shows 350000 as I'd expect.
I put everything in the one namespace.
xmlns:local="clr-namespace:WpfApp1"
mc:Ignorable="d"
Title="MainWindow" Height="800" Width="1200">
<Window.DataContext>
<local:PaymentFactorViewModel/>
</Window.DataContext>
<Grid>
<TextBox x:Name="txtPrice" Text="{Binding PaymentFactor.Price,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/>
</Grid>
</Window>
public class PaymentFactorViewModel : ViewModelBase
{
public PaymentFactorViewModel()
{
PaymentFactor = new Payment();
PaymentFactor.Price=350000;
}
private Payment _paymentFactor;
public Payment PaymentFactor
{
get { return _paymentFactor; }
set
{
_paymentFactor = value;
OnPropertyChanged(nameof(PaymentFactor));
}
}
}
public class Payment:ViewModelBase
{
private long _paymentId;
private decimal _price;
public long PaymentId {
get { return _paymentId; }
set
{
_paymentId = value;
OnPropertyChanged(nameof(PaymentId));
}
}
public decimal Price {
get { return _price; }
set
{
_price = value;
OnPropertyChanged(nameof(Price));
}
}
}
Related
I want to read some data from database and do some process on them and then view them in the view.
I read a lot about MVVM and now I am confused.
Imaging I read a person entity from database with Name attribute.
please make a small code and show me how should I make my model and ViewModel.
I guess it we will be something like this :
public class PersonModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private string Name;
public string name
{
get
{
return Name;
}
set
{
Name = value;
onpropertychanged("name");
}
}
public PersonModel( string s)
{
name = s;
}
public void onpropertychanged(string PName)
{
if (PropertyChanged !=null)
{
PropertyChanged(this, new PropertyChangedEventArgs(PName));
}
}
}
public class PersonViewModel
{
public ObservableCollection <PersonModel> list { get; set; }
public PersonViewModel()
{
list = new ObservableCollection<model>();
list.Add(new model("abc"));
list.Add(new model("def"));
}
public void change()
{
list[1].name = "changed";
}
}
public class ViewModelBase
{
public PersonViewModel vperson { get; set; }
public ViewModelBase()
{
vperson = new PersonViewModel();
vperson.change();
}
}
Edite : Where should database connections be?
Edite :
<Grid>
<TextBox Text="{Binding vperson.list[1].name}" />
</Grid>
</Window>
I edited your classes and is working
public class PersonModel : INotifyPropertyChanged
{
private string _name;
public string Name
{
get => _name;
set
{
if (_name == value) return;
_name = value;
OnPropertyChanged();
}
}
public PersonModel(string name)
{
_name = name;
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName]string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
public class PersonViewModel
{
public ObservableCollection<PersonModel> Items { get; set; }
public PersonViewModel()
{
Items = new ObservableCollection<PersonModel> { new PersonModel("abc"), new PersonModel("def") };
}
public void Change()
{
Items[1].Name = "changed";
}
}
public class ViewModelBase
{
public PersonViewModel PersonViewModel { get; set; }
public ViewModelBase()
{
PersonViewModel = new PersonViewModel();
PersonViewModel.Change();
}
}
//Use the dataContext in this way, will help you with the strong type
xmlns:viewModels="clr-namespace:WpfApp1.ViewModels"
<Window.DataContext>
<viewModels:ViewModelBase />
</Window.DataContext>
<Grid>
<TextBox Text="{Binding PersonViewModel.Items[1].Name}" />
</Grid>
I'm having a problem with using MVVM for a Xamarin project.
I can not refresh the user interface if one of my objects in my viewModel is updated (after a PUT request, for example).
Let me explain :
My model :
public class MyObject
{
public string Id { get; private set; }
public string Name { get; private set; }
}
My viewmodel :
public class MyViewModel : BaseViewModel
{
public MyObject MyObject { get; private set; }
public string IdMvvm
{
set
{
if (this.MyObject.Id != value)
{
MyObject.Id = value;
OnPropertyChanged(nameof(IdMvvm));
}
}
get { return MyObject.Id; }
}
public string NameMvvm
{
set
{
if (this.MyObject.Name != value)
{
MyObject.Name = value;
OnPropertyChanged(nameof(NameMvvm));
}
}
get { return MyObject.Name; }
}
}
BaseViewModel implements INotifyPropertyChanged
public class BaseViewModel : INotifyPropertyChanged
{
public string PageTitle { get; protected set; }
LayoutViewModel() {}
// MVVM ----------------------------------------------------------------------------------------
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
protected void SetValue<T>(ref T backingField, T value, [CallerMemberName] string propertyName = null)
{
if (EqualityComparer<T>.Default.Equals(backingField, value))
return;
backingField = value;
OnPropertyChanged(propertyName);
}
MyViewModel is defined as BindingContext for my page
My properties IdMvvm and NameMvvm are bind in Entry in my page in xaml
When I modify an Entry then the value is raised but if my MyModel object changes value, for example update (click on a button) then the value of the different Entry is not updated
Can you help me please? Because it seems that I missed something ...
If you need more explanation, tell me to know
Sorry if my english is not good
It is because when you change the model, your view is not aware about the change. Update your code so that you explicitly notify property changes when your model changes.
public class MyViewModel : BaseViewModel
{
private MyObject _myObject;
public MyObject MyObject
{
get { return _myObject; }
private set { _myObject = value; NotifyModelChange(); }
}
public string IdMvvm
{
set
{
if (this.MyObject.Id != value)
{
MyObject.Id = value;
OnPropertyChanged(nameof(IdMvvm));
}
}
get { return MyObject.Id; }
}
public string NameMvvm
{
set
{
if (this.MyObject.Name != value)
{
MyObject.Name = value;
OnPropertyChanged(nameof(NameMvvm));
}
}
get { return MyObject.Name; }
}
private void NotifyModelChange()
{
OnPropertyChanged(nameof(IdMvvm));
OnPropertyChanged(nameof(NameMvvm));
}
}
I have a project where I need to display a list of contract (Class Affaire).
Each contract has a list of phases (Class Phase).
I display each of them in 2 different ListView using binding.
Problem is when I remove a Phase from ListView, nor the ListView where are displayed Phases, nor my ObjectCollection are updated.
I created a context with two distinct ObservableCollection :
ObservableCollection, where is the list of Affaire.
ObservableCollection that are list of phases present in selected Affaire
My context is made as follow :
public class Contexte : INotifyPropertyChanged
{
private Affaire selectedAffaire;
private Phase selectedPhase;
private Assemblage selectedAssemblage;
public Affaire SelectedAffaire
{
get { return selectedAffaire; }
set
{
selectedAffaire = value;
this.NotifyPropertyChanged("SelectedAffaire");
}
}
public Phase SelectedPhase
{
get { return selectedPhase; }
set
{
selectedPhase = value;
this.NotifyPropertyChanged("SelectedPhase");
}
}
public Assemblage SelectedAssemblage
{
get { return selectedAssemblage; }
set
{
selectedAssemblage = value;
this.NotifyPropertyChanged("SelectedAssemblage");
}
}
private ObservableCollection<Affaire> listeDesAffaires;
public ObservableCollection<Affaire> ListeDesAffaires
{
get { return listeDesAffaires; }
set { NotifyPropertyChanged(ref listeDesAffaires, value); }
}
/**************************************************/
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string nomPropriete)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(nomPropriete));
}
private bool NotifyPropertyChanged<T>(ref T variable, T valeur, [CallerMemberName] string nomPropriete = null)
{
if (object.Equals(variable, valeur)) return false;
variable = valeur;
NotifyPropertyChanged(nomPropriete);
return true;
}
}
My Class Affaire :
public class Affaire : INotifyPropertyChanged
{
public long ID { get; set; }
private string nom;
public string Nom
{
get { return this.nom; }
set
{
if (this.nom != value)
{
this.nom = value;
this.NotifyPropertyChanged("Nom");
}
}
}
private string code;
public string Code
{
get { return this.code; }
set
{
if (this.code != value)
{
this.code = value;
this.NotifyPropertyChanged("Code");
}
}
}
private string comm;
public string Comm
{
get { return this.comm; }
set
{
if (this.comm != value)
{
this.comm = value;
this.NotifyPropertyChanged("Comm");
}
}
}
private ObservableCollection<Phase> listPhases;
public ObservableCollection<Phase> ListPhases {
get { return listPhases; }
set
{
listPhases = value;
if (PropertyChanged != null)
{
NotifyPropertyChanged("ListPhases");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
....
}
My class Phase :
public class Phase : INotifyPropertyChanged
{
private string nomPhase;
public string NomPhase
{
get { return this.nomPhase; }
set
{
if (this.nomPhase != value)
{
this.nomPhase = value;
this.NotifyPropertyChanged("NomPhase");
}
}
}
private int priorite;
public int Priorite
{
get { return this.priorite; }
set
{
if (this.priorite != value)
{
this.priorite = value;
this.NotifyPropertyChanged("Priorite");
}
}
}
private string commPhase;
public string CommPhase
{
get { return this.commPhase; }
set
{
if (this.commPhase != value)
{
this.commPhase = value;
this.NotifyPropertyChanged("CommPhase");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
public long IdAffaire { get; set; }
public long ID { get; set; }
private ObservableCollection<Assemblage> listAssemblages;
public ObservableCollection<Assemblage> ListAssemblages
{
get { return listAssemblages; }
set
{
listAssemblages = value;
if (PropertyChanged != null)
{
NotifyPropertyChanged("ListAssemblages");
}
}
}
...
}
1) When I doubleclick on a contract(in ListView1), I display in ListView2 list of its phases, I do the following :
contexte.SelectedAffaire = (Affaire)ListView1.SelectedItem;
contexte.SelectedAffaire.getListPhases();
afficherListview("2");
2) When I edit my Phase, all is updated correctly in my view, and also in my ObservableCollection
3) For adding/removing a new Phase, all is solved.
Edit :
Example given by Netstep works perfectly but I still meet an issue :
I have a third level "Assembly", this is an ObservableCollection in class "Phase", I have no problem to navigate with the four ListViews, but I meet a problem when I want to make something else : When I right-click on the header of "Phase", I want to display in the list of Assembly, the list of all assemblies contained in Affaire, without filtering on Phase.
For this I do the following : I am on the 3rd level listview Assemblies, I make right click on Phase header and event is as following :
Phase ph = new Phase();
ph.IdAffaire = contexte.SelectedAffaire.ID;
ph.ListAssemblages = new ObservableCollection<Assemblage>(contexte.SelectedAffaire.getListAssemblages(true));
contexte.SelectedPhase = ph;
I "shit" a bit making a new empty phase, just to put an ObservableCollection inside and bind the ObservableCollection to my ListView3.
Edit : That part of code works good... I just refreshed the context somewhere in my code and forgot about it, sure that there was something wrong in biding... All solved thanks
Here is the example, based on your source, that will handle all stuff.
a View Models:
using System.Collections.ObjectModel;
using System.ComponentModel;
namespace WpfApp2
{
public class BaseViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string nomPropriete)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(nomPropriete));
}
}
public class Contexte : BaseViewModel
{
private Affaire _selectedAffaire;
private Phase _selectedPhase;
public ObservableCollection<Affaire> ListeDesAffaires { get; set; }
public Affaire SelectedAffaire
{
get { return _selectedAffaire; }
set
{
_selectedAffaire = value;
this.NotifyPropertyChanged("SelectedAffaire");
}
}
public Phase SelectedPhase
{
get { return _selectedPhase; }
set
{
_selectedPhase = value;
this.NotifyPropertyChanged("SelectedPhase");
}
}
public Contexte()
{
ListeDesAffaires = new ObservableCollection<Affaire>
{
new Affaire("Affaire1"),
new Affaire("Affaire2")
};
}
}
public class Affaire : BaseViewModel
{
private string nom;
public string Nom
{
get { return this.nom; }
set
{
this.nom = value;
this.NotifyPropertyChanged("Nom");
}
}
public ObservableCollection<Phase> ListPhases { get; set; }
public Affaire(string n)
{
nom = n;
ListPhases = new ObservableCollection<Phase>
{
new Phase { NomPhase = nom + "_Phase1" },
new Phase { NomPhase = nom + "_Phase2" }
};
}
}
public class Phase : BaseViewModel
{
private string nomPhase;
public string NomPhase
{
get { return this.nomPhase; }
set
{
this.nomPhase = value;
this.NotifyPropertyChanged("NomPhase");
}
}
public ObservableCollection<Assemblage> ListAssemblages { get; set; }
}
public class Assemblage : BaseViewModel
{
private string nom;
public string Nom
{
get { return this.nom; }
set
{
this.nom = value;
this.NotifyPropertyChanged("Nom");
}
}
}
}
a MainWindow.xaml:
<Window x:Class="WpfApp2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApp2"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:Contexte x:Name="Contexte" d:IsDataSource="True" />
</Window.DataContext>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>
<ListBox ItemsSource="{Binding ListeDesAffaires}" DisplayMemberPath="Nom" SelectedItem="{Binding SelectedAffaire}"/>
<ListBox Grid.Column="1" ItemsSource="{Binding SelectedAffaire.ListPhases}" DisplayMemberPath="NomPhase" />
<Button Grid.Column="2" VerticalAlignment="Top" Click="FillClick">Fill</Button>
<ListBox Grid.Column="2" ItemsSource="{Binding SelectedPhase.ListAssemblages}" DisplayMemberPath="Nom" Margin="0,20,0,0"/>
</Grid>
</Window>
And some code from your question (MainWindow.xaml.cs):
using System.Collections.ObjectModel;
using System.Windows;
namespace WpfApp2
{
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void FillClick(object sender, RoutedEventArgs e)
{
Phase ph = new Phase();
ph.NomPhase = "SomeId";
ph.ListAssemblages = new ObservableCollection<Assemblage>()
{
new Assemblage { Nom = "Assemblage1" },
new Assemblage { Nom = "Assemblage2" }
};
Contexte.SelectedPhase = ph;
}
}
}
And here is the result:
This is basic sample that you can extend. It handles all field modification and Add/Remove objects and displays on screen. There is no additional code in MainWindow.xaml.cs. Please ask questions, if any.
This is my first question so I'll do my best.
I'm trying to get a simple WPF DataGrid control to be "refreshed" using ObservableCollection and MVVM as the numerous tutorials on the web explain.
In context, these are my model clases:
(PersonViewModel.cs)
public class PersonViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private int _id;
private int _idAddress;
private string _name;
private int _age;
private string _address;
public int Id
{
get { return this._id; }
set
{
if (value != this._id)
{
this._id = value;
OnPropertyChanged();
}
}
}
public int IdAddress
{
get { return this._idAddress; }
set
{
if (value != this._idAddress)
{
this._idAddress = value;
OnPropertyChanged();
}
}
}
public string Name
{
get { return this._name; }
set
{
if (value != this._name)
{
this._name = value;
OnPropertyChanged();
}
}
}
public int Age
{
get { return this._age; }
set
{
if (value != this._age)
{
this._age = value;
OnPropertyChanged();
}
}
}
public string Address
{
get { return this._address; }
set
{
if (value != this._address)
{
this._address = value;
OnPropertyChanged();
}
}
}
private void OnPropertyChanged([CallerMemberName]String caller = null)
{
var handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(caller));
}
}
}
(AddressViewModel.cs)
public class AddressViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private int _id;
private string _street;
private int _number;
public int Id
{
get { return this._id; }
set
{
if (value != this._id)
{
this._id = value;
OnPropertyChanged();
}
}
}
public string Street
{
get { return this._street; }
set
{
if (value != this._street)
{
this._street = value;
OnPropertyChanged();
}
}
}
public int Number
{
get { return this._number; }
set
{
if (value != this._number)
{
this._number = value;
OnPropertyChanged();
}
}
}
private void OnPropertyChanged([CallerMemberName]String caller = null)
{
var handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(caller));
}
}
}
And here's a representation of the database model (cannot upload pic < 10 posts)
Address
Id
Street
Number
Person
Id
IdAddress
Name
Age
Address ---> this property concatenates Street and Number of Address entity.
So, as you can see, it's a very simple example. Just a proof-of-concept. Problem is, whenever I try to add a new entity to the database (through Entity Framework 6 and LINQ) I must inevitably add that ViewModel entity to the DataGrid's data context.
This is the code working as of today:
public static Person CreatePerson(PersonViewModel personVM)
{
var person = new Person
{
IdAddress = personVM.IdAddress,
Name = personVM.Name,
Age = personVM.Age
};
try
{
using (var context = new OCDemoContext())
{
context.Database.Connection.Open();
context.Person.Add(person);
context.SaveChanges();
context.Database.Connection.Close();
}
}
catch
{
throw;
}
return person;
}
As you can see, the need here is to show in DataGrid a column that concatenates two properties of Address database entity: Street and Number, and giving that value to Address property of PersonViewModel class to show as a column in the DataGrid.
The code that adds the entity to the DataGrid itemssource collection after the insert to the database:
// Add to the database
PersonsGateway.CreatePerson(personVM);
// Update view on DataGrid's itemssource collection
ViewModel model = this.xGrid.DataContext as ViewModel;
model.Persons.Insert(0, personVM);
XAML as:
<Window x:Class="OCDemo.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525" xmlns:local="clr-namespace:OCDemo">
<Window.Resources>
<local:ViewModel x:Key="xViewModel" />
</Window.Resources>
<Grid x:Name="xGrid" DataContext="{StaticResource xViewModel}">
<DataGrid x:Name="xDataGrid" Grid.Row="0" ItemsSource="{Binding Persons}" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding Path=Name}" Header="Name"/>
<DataGridTextColumn Binding="{Binding Path=Age}" Header="Age"/>
<DataGridTextColumn Binding="{Binding Path=Address}" Header="Address"/>
</DataGrid.Columns>
</DataGrid>
</Grid>
And ViewModel.cs
public class ViewModel
{
public ObservableCollection<PersonViewModel> Persons { get; set; }
public ViewModel()
{
this.Persons = PersonsGateway.RetrievePersons();
}
}
And T4 .tt file updated as MSDN - Updating code generation for data binding explains.
So, it is possible to depend only on adding the entity to the database and not to always add the entity to the itemssource collection after that on a ObservableCollection scenario?
Change your view model to the following
public class ViewModel
{
public ObservableCollection<PersonViewModel> Persons { get; private set; }
public ViewModel()
{
Persons = new ObservableCollection<PersonViewModel>();
Persons.AddRange(PersonsGateway.RetrievePersons().ToList());
}
}
Its important to create the observable collection once and not recreate it, to rely on change notifications, so create it and then use the standard methods to manage it.
Ok, I should of suggested that instead of this code
PersonsGateway.CreatePerson(personVM);
ViewModel model = this.xGrid.DataContext as ViewModel;
model.Persons.Insert(0, personVM);
you should do
PersonsGateway.CreatePerson(personVM);
ViewModel model = this.xGrid.DataContext as ViewModel;
model.Persons.Add(personVM);
I made an example as simple as possible.
I have a class ViewModelMain whose will implement several viewmodels.
I am trying to bind my slider value on a viewmodel in my ViewModelMain.
Here my code:
MainWindow.xaml.cs
I set the datacontext here, don't know if it is realy a good idea.
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
VMMain vm = new VMMain();
this.DataContext = vm;
}
}
MainWindow.xaml
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Slider Height="23" Name="page_slider" Width="100" Value="{Binding Path=p.NbrLine}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Minimum="0" Maximum="10"/>
<TextBox Text="{Binding Value, ElementName=page_slider, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Height="28" HorizontalAlignment="Stretch" Name="Voiture1Label" VerticalAlignment="Stretch" Margin="0,110,0,172"></TextBox>
</Grid></Window>
ViewModelMain.cs
ViewModelBase : the class which implement the INotifyPropertyChanged
ModelPage : my model
MyPage : my sub viewmode which is the viewmodel of ModelPage
ViewModelMain : my final viewmodel which will implement more viewmodel
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propName));
}
}
}
public class ModelPage
{
public int NbrLine { get; set; }
public int NbrCapsLock { get; set; }
}
public class MyPage : ViewModelBase
{
private ModelPage _model;
public MyPage(ModelPage m)
{
_model = m;
}
public int NbrLine
{
get { return (_model.NbrLine); }
set
{
if (_model.NbrLine == value) return;
_model.NbrLine = value;
OnPropertyChanged("NbrLine");
}
}
public int NbrCapsLock
{
get { return (_model.NbrCapsLock); }
set
{
if (_model.NbrCapsLock == value) return;
_model.NbrCapsLock = value;
OnPropertyChanged("NbrCapsLock");
}
}
}
public class ViewModelMain
{
public MyPage p;
public ViewModelMain()
{
p = new MyPage(new ModelPage(){NbrLine = 5, NbrCapsLock = 1});
}
}
when i launch it, my slider is still on 0 doesn't understand why it is not on 5.
p is a field, not a property. You should only bind to properties:
public MyPage p { get; set; }
Actually you chould transform p into property like that. WPF can not bind to simple attributes.
public class ViewModelMain
{
public MyPage p { get; set; }
public ViewModelMain()
{
p = new MyPage(new ModelPage() { NbrLine = 5, NbrCapsLock = 1 });
}
}