BindingMode.TwoWay does not work with UserControl (not update source property) - mvvm

I have created Custom User Control which contain TextBox and PasswordBox. it is binding completely work but when i changed any value inside TextBox or PasswordBox of user control then my source property does not getting refreshed.
Following are the code for my Custom User Control
RestrictedBox.xaml
<UserControl.Resources>
<Converters:EnumToVisibilityConverter x:Key="enumToVisibilityConverter" />
<Converters:EnumToVisibilityConverterReverse x:Key="enumToVisibilityConverterReverse" />
</UserControl.Resources>
<Grid x:Name="LayoutRoot" Background="Transparent" >
<StackPanel>
<TextBox x:Name="txtTextBox" Width="50" Height="25" />
<PasswordBox x:Name="txtPasswordBox" Width="50" Height="25" />
</StackPanel>
</Grid>
RestrictedBox.xaml.cs
public partial class RestrictedBox : UserControl
{
public RestrictedBox()
{
InitializeComponent();
txtTextBox.SetBinding(TextBox.TextProperty, new Binding { Source = this, Path = new PropertyPath("Value"), Mode = BindingMode.TwoWay });
txtTextBox.SetBinding(TextBox.VisibilityProperty, new Binding("Type")
{
Source = this,
Converter = new EnumToVisibilityConverter()
});
txtPasswordBox.SetBinding(PasswordBox.PasswordProperty, new Binding { Source = this, Path = new PropertyPath("Value"), Mode = BindingMode.TwoWay });
txtPasswordBox.SetBinding(TextBox.VisibilityProperty, new Binding("Type")
{
Source = this,
Converter = new EnumToVisibilityConverterReverse()
});
}
public string Value
{
get { return (string)GetValue(ValueProperty); }
set { SetValue(ValueProperty, value); }
}
public static readonly DependencyProperty ValueProperty = DependencyProperty.Register("Value", typeof(string), typeof(RestrictedBox), new PropertyMetadata("", ValueChanged));
private static void ValueChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
}
public Mode Type
{
get { return (Mode)GetValue(TypeProperty); }
set { SetValue(TypeProperty, value); }
}
public static readonly DependencyProperty TypeProperty = DependencyProperty.Register("Type", typeof(Mode), typeof(RestrictedBox), new PropertyMetadata(Mode.Text, TypeChanged));
private static void TypeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
}
}
Following are the code for LoginView where i have used my custom User Control (RestrictedBox).
LoginView.xaml
<control:RestrictedBox Type="Text" Value="{Binding Path=UserName}" />
LoginView.xaml.cs
[Export(typeof(LoginView))]
[PartCreationPolicy(CreationPolicy.NonShared)]
public partial class LoginView : UserControl, IPageTitle
{
#region Constuctors
public LoginView()
{
InitializeComponent();
}
[Import]
public LoginViewModel ViewModel
{
get
{
return this.DataContext as LoginViewModel;
}
set
{
DataContext = value;
}
}
#endregion
}
LoginViewModel.cs
[Export]
[PartCreationPolicy(CreationPolicy.NonShared)]
public class LoginViewModel : INotifyPropertyChanged, IRegionMemberLifetime
{
private string _UserName = "";
public string UserName
{
get { return _UserName; }
set
{
_UserName = value;
OnPropertyChanged("UserName");
}
}
[ImportingConstructor]
public LoginViewModel(IEventAggregator eventAggregator, IRegionManager regionManager)
{
}
}
Please help me to resolved this because i am trying to resolve since last 1.5 days without any luck.
Your comments and suggestions would be highly appreciated.
Note:- I am able to bind value of the UserName to TextBox but i update TextBox and click on submit i couldn't getting updated value from TextBox.
Thanks,
Imdadhusen

You are missing Mode=TwoWay in you LoginView.xaml:
<control:RestrictedBox Type="Text" Value="{Binding Path=UserName,Mode=TwoWay}" />

Related

How can I pass object while navigating? [duplicate]

This question already has an answer here:
How pass parameter when navigate to another page (Shell)
(1 answer)
Closed 4 months ago.
I have main page on which I have collection view. I want to navigate to next page after I click submit button .I am able to navigate to the next page but I also want total list of items which I have in my collection how can I achieve that?
I don't know the detail of your code, but you can try to pass the total list of items as the parameter of the next page.(suppose it's name is SecondPage)
You can refer to the following code:
MainPage.cs
public partial class MainPage : ContentPage
{
MyViewModel myViewModel;
public MainPage()
      {
            InitializeComponent();
myViewModel = new MyViewModel();
BindingContext = myViewModel;
}
      private void mCollectionView_SelectionChanged(object sender, SelectionChangedEventArgs e)
      {
string previous = (e.PreviousSelection.FirstOrDefault() as MyModel)?.Name;
string current = (e.CurrentSelection.FirstOrDefault() as MyModel)?.Name;
}
private async void Button_Clicked(object sender, EventArgs e)
{
// here we can pass the data we need.
var secondPage = new SecondPage(myViewModel.Data);
await Navigation.PushAsync(secondPage);
}
}
MainPage.xaml.cs
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="MauiCollectionApp.MainPage"
xmlns:local="clr-namespace:MauiCollectionApp"
x:Name="myPage"
>
<VerticalStackLayout>
<CollectionView ItemsSource="{ Binding Data}" x:Name="mCollectionView"
SelectionChanged="mCollectionView_SelectionChanged"
SelectionMode="Single"
>
<CollectionView.ItemTemplate>
<DataTemplate>
<HorizontalStackLayout Margin="3" >
<Label Text="{Binding Name}" BackgroundColor="Gray"/>
<Label Text="{Binding Car.Make}" Margin="5,0,5,0" />
<Button Text="delete" Margin="10,0,0,0"
BackgroundColor="Red"
Command="{Binding Path= BindingContext.RemoveEquipmentCommand,Source={Reference mCollectionView }}" CommandParameter="{Binding .}"
/>
</HorizontalStackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
<Button Text="submit" Clicked="Button_Clicked" Margin="10"/>
</VerticalStackLayout>
</ContentPage>
MyViewModel.cs
public class MyViewModel: INotifyPropertyChanged
{
public ObservableCollection<MyModel> Data { get; set; }
public ICommand RemoveEquipmentCommand => new Command<MyModel>(ReMoveItem);
private void ReMoveItem(MyModel obj)
{
System.Diagnostics.Debug.WriteLine(" the selected item's name is: " + obj.Name );
Data.Remove(obj);
}
public MyViewModel() {
Data = new ObservableCollection<MyModel>();
Data.Add(new MyModel { Name ="model_1", Car= new Vehicle {Make="Make1" } });
Data.Add(new MyModel { Name = "model_2", Car = new Vehicle { Make = "Make2" } });
Data.Add(new MyModel { Name = "model_3", Car = new Vehicle { Make = "Make3" } });
Data.Add(new MyModel { Name = "model_4", Car = new Vehicle { Make = "Make4" } });
}
bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
{
if (Object.Equals(storage, value))
return false;
storage = value;
OnPropertyChanged(propertyName);
return true;
}
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
public event PropertyChangedEventHandler PropertyChanged;
}
SecondPage.cs
public partial class SecondPage : ContentPage
{
public ObservableCollection<MyModel> Items { get; set; }
public SecondPage(ObservableCollection<MyModel> data )
      { // we can get the passed data here
            InitializeComponent();
            this.Items = data;
      }
}

data is not getting in viewmodel on Icommand button click

I have a form for capturing data from user.
<StackLayout Spacing="10" Margin="20,10,20,0">
<Label Text="Job Name"></Label>
<Entry BackgroundColor="White" x:Name="JobName" Text="{Binding SelectedJob.Name,Mode=TwoWay}"/>
<Label Text="Goal"></Label>
<Entry BackgroundColor="White" x:Name="Goal" Text="{Binding SelectedJob.Goal,Mode=TwoWay}"/>
<Grid ColumnSpacing="8" HorizontalOptions="FillAndExpand">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Button Text="Save" Command="{Binding SubmitCommand}" BackgroundColor="#078fc1" Grid.Column="0" HorizontalOptions="FillAndExpand"/>
<Button Text="Reset" BackgroundColor="#078fc1" Grid.Column="1" HorizontalOptions="FillAndExpand"/>
</Grid>
</StackLayout>
on button click i want to bind data to SelectedJob object.
this is my ViewModel
public class JobViewModel: INotifyPropertyChanged
{
public JobViewModel()
{
SubmitCommand = new Command(OnSubmitAsync);
}
private JobDTO selectedob { get; set; }
public JobDTO SelectedJob
{
get { return selectedob; }
set
{
selectedob = value;
OnPropertyChanged(nameof(SelectedJob));
}
}
public ICommand SubmitCommand { protected set; get; }
public async void OnSubmitAsync()
{
await.jobservice.postjob()
}
}
and this is my model
public class JobDTO:INotifyPropertyChanged
{
private string name { get; set; }
public string Name
{ get { return name;}
set
{
name = value;
OnPropertyChanged(nameof(Name));
}
}
private string goal;
public string Goal
{
get { return goal; }
set
{
goal = value;
OnPropertyChanged(nameof(Goal));
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
on button click i am getting SelectedJob as null,eventhough i made my class as JobDTO:INotifyPropertyChanged.can any one help me what i am doing here wrong.
I changed the code of ViewModel and model.
There is GIF of demo based on your code.
ViewModel of JobViewModel
If you want to used get/set method, one attribute corresponds to one get/set method, I also add OnPropertyChangedmethod.
public class JobViewModel : INotifyPropertyChanged
{
public JobViewModel()
{
SubmitCommand = new Command(OnSubmitAsync);
}
private JobDTO selectedob=new JobDTO();
public JobDTO SelectedJob
{
get { return selectedob; }
set
{
selectedob = value;
OnPropertyChanged("SelectedJob");
}
}
public ICommand SubmitCommand { protected set; get; }
public event PropertyChangedEventHandler PropertyChanged;
public async void OnSubmitAsync()
{
// i donnot know what is your aim of this part, i just pop up a alert that contains Name and Goal from Entry.
await Application.Current.MainPage.DisplayAlert("Alert", "Name: "+SelectedJob.Name+"\n"+ "Goal: "+ SelectedJob.Goal , "Ok");
}
protected virtual void OnPropertyChanged(string propertyName)
{
var changed = PropertyChanged;
if (changed != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
Model of JobDTO, The changed place is same with ViewModel
public class JobDTO: INotifyPropertyChanged
{
private string name;
public string Name
{
get { return name; }
set
{
name = value;
OnPropertyChanged("Name");
}
}
private string goal;
public string Goal
{
get { return goal; }
set
{
goal = value;
OnPropertyChanged("Goal");
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
var changed = PropertyChanged;
if (changed != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
MainPage.xaml
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:local="clr-namespace:DateBoundingDemo"
x:Class="DateBoundingDemo.MainPage">
<StackLayout Spacing="10" Margin="20,10,20,0">
<Label Text="Job Name"></Label>
<Entry BackgroundColor="White" x:Name="JobName" Text="{Binding SelectedJob.Name,Mode=TwoWay}"/>
<Label Text="Goal"></Label>
<Entry BackgroundColor="White" x:Name="Goal" Text="{Binding SelectedJob.Goal,Mode=TwoWay}"/>
<Grid ColumnSpacing="8" HorizontalOptions="FillAndExpand">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Button Text="Save" Command="{Binding SubmitCommand}" BackgroundColor="#078fc1" Grid.Column="0" HorizontalOptions="FillAndExpand"/>
<Button Text="Reset" BackgroundColor="#078fc1" Grid.Column="1" HorizontalOptions="FillAndExpand"/>
</Grid>
</StackLayout>
</ContentPage>
MainPage.xaml.cs
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
BindingContext =new JobViewModel();
}
}

Xamarin Forms MVVM Databinding failing when I'm binding to a single object

I'm having an issue with data not binding correctly on a details page when I have clicked through from a ListView via a button. The ListView binds perfectly and the object gets passed through to the details page. The Id of the object is read and a full version of the object is called from an API and set to a new instance of the object. When I add a breakpoint, the full object is available, but Labels on the view aren't populated. Here is the ViewModel:
DetailsViewModel.cs
public class DetailsViewModel
{
public Deal Deal { get; set; }
public int DealId { get; set; }
public DetailsViewModel(int id)
{
Deal = new Deal();
DealId = id;
}
public async void GetDeal()
{
var deal = await Deal.GetDeal(DealId);
if(deal != null)
{
Deal = deal;
}
}
}
The codebehind looks like this:
DetailPage.Xaml.cs
DetailsViewModel viewModel;
int dealId;
public DetailPage(int id)
{
InitializeComponent();
dealId = id;
viewModel = new DetailsViewModel(dealId);
BindingContext = viewModel;
}
protected override void OnAppearing()
{
base.OnAppearing();
viewModel.GetDeal();
}
And the Xaml file is
DetailPage.Xaml
<ContentPage.Content>
<ScrollView>
<StackLayout x:Name="detailsLayout">
<Label Text="{Binding Deal.Name}" />
</StackLayout>
</ScrollView>
</ContentPage.Content>
When I put a breakpoint in Deal = deal on DetailsViewModel, the Deal object exists and has the correct data, but I just get a blank screen. I have tried Labels with Text="{Binding Name}" and Text="{Binding Deal.Name}".
I have also tried manually creating a deal in the GetDeal function of the ViewModel and still nothing is bound.
1) Ensure your property Notifies the UI of a change implementing the INotifyPropertyChanged interface. See https://learn.microsoft.com/en-us/xamarin/xamarin-forms/xaml/xaml-basics/data-bindings-to-mvvm
2) Ensure the set is done on the UI thread using Device.BeginInvokeOnMainThread. https://learn.microsoft.com/fr-fr/dotnet/api/xamarin.forms.device.begininvokeonmainthread?view=xamarin-forms
using System.ComponentModel;
using System.Runtime.CompilerServices;
using Xamarin.Forms;
namespace YourNamespace
{
public class DetailsViewModel : INotifyPropertyChanged
{
private Deal _deal;
public Deal Deal
{
get => _deal;
set
{
if (_deal != value)
{
_deal = value;
OnPropertyChanged();
}
}
}
public int DealId { get; set; }
public DetailsViewModel(int id)
{
//!! useless assignation
//Deal = new Deal();
DealId = id;
}
public async void GetDeal()
{
var deal = await Deal.GetDeal(DealId);
if (deal != null)
{
//Ensure we are on UI thread
Device.BeginInvokeOnMainThread(() => Deal = deal);
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
}

Prism Forms INavigationAware OnNavigatingTo not updating ObservableCollection

I am using Prism which helps me in binding my view to the view model. Using INavigationAware, I am hoping to update the Observable collection in my Listview from OnNavigatingTo(). On debugging this method is accessible, however it does not seem to update the ObservableCollection that is bound to the view.
Below is the ViewModel, that is inherited from Prism's BindableBase and INavigationAware:
public class QuoteDetailPageViewModel : BindableBase, INavigationAware
{
private string _title;
public string Title
{
get { return _title; }
set { SetProperty(ref _title, value); }
}
private ObservableCollection<Message> _messages;
private ObservableCollection<Message> Messages
{
get { return _messages; }
set { SetProperty(ref _messages, value); }
}
private Author _selectedAuthor;
private Author SelectedAuthor
{
get { return _selectedAuthor; }
set { SetProperty(ref _selectedAuthor, value); }
}
public QuoteDetailPageViewModel(INavigationService navigationService)
{
Title = "Text Messages";
}
public void OnNavigatingTo(NavigationParameters parameters)
{
var id = -1;
if (parameters != null && parameters.ContainsKey("id"))
{
int.TryParse(parameters["id"].ToString(), out id);
}
if (id > 0)
{
Title = "Contact Message";
}
var msgs = new List<Message>()
{
new Message() {Text = "An investment in knowledge pays the best
interest."},
new Message() {Text = "Early to bed and early to rise makes a
man healthy, wealthy, and wise."},
new Message()
{
Text = "It's fine to celebrate success but it is more
important to heed the lessons of failure."
},
};
Messages = new ObservableCollection<Message>(msgs);
}
public void OnNavigatedFrom(NavigationParameters parameters)
{
}
public void OnNavigatedTo(NavigationParameters parameters)
{
}
}
public class Message
{
public string Text { get; set; }
}
And Below is the xaml code:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
prism:ViewModelLocator.AutowireViewModel="True"
x:Class="PrismAppTutorial.Views.QuoteDetailPage"
Title="{Binding Title}">
<StackLayout Margin="0,20,0,0">
<ListView x:Name="lvAuthorQuotes"
ItemsSource="{Binding Messages}"
HasUnevenRows="True">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout Padding="20,10"
Orientation="Vertical"
HorizontalOptions="FillAndExpand"
VerticalOptions="StartAndExpand">
<Label Text="{Binding Text}"
HorizontalOptions="StartAndExpand"
VerticalOptions="StartAndExpand"
LineBreakMode="WordWrap" />
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</ContentPage>
Anyone knows how to fix this?
Turns out I had set the Messages as private and not public. This needs to be public so as to be applied in the view.

UWP Binding to AutoSuggestBox in MVVM

i am invoking the QuerySubmitted command of the AutoSuggestBox control in UWP.
the command binds to ICommand in the view model.
the problem is it requires to accept AutoSuggestBoxQuerySubmittedEventArgs which is pure UI and it's not acceptable in MVVM.
my code looks like that:
<AutoSuggestBox Name="SearchAutoSuggestBox"
PlaceholderText="Search by keywords"
QueryIcon="Find"
>
<interactivity:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="QuerySubmitted">
<core:InvokeCommandAction Command="{x:Bind ViewModel.SearchCommand}" />
</core:EventTriggerBehavior>
</interactivity:Interaction.Behaviors>
</AutoSuggestBox>
and my view model looks like that:
public DelegateCommand<AutoSuggestBoxQuerySubmittedEventArgs> SearchCommand { get; }
public MainPageViewModel()
{
SearchCommand = new DelegateCommand<AutoSuggestBoxQuerySubmittedEventArgs>(ExecuteMethod);
}
private void ExecuteMethod(AutoSuggestBoxQuerySubmittedEventArgs o)
{
// CODE HERE
}
ofcours AutoSuggestBoxQuerySubmittedEventArgs is not acceptable in the view model.
looking for alternatives...
same goes to SuggestionChosen...
InvokeCommandAction has a parameter named InputConverter which you can use to convert the event args to some other parameter that can be passed to your ViewModel.
First create a IValueConverter class to extract what you need from your event args like this:-
public class AutoSuggestQueryParameterConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, string language)
{
// cast value to whatever EventArgs class you are expecting here
var args = (AutoSuggestBoxQuerySubmittedEventArgs)value;
// return what you need from the args
return (string)args.ChosenSuggestion;
}
}
Then use that converter in your XAML like this:
<Page.Resources>
<converters:AutoSuggestQueryParameterConverter x:Key="ArgsConverter" />
</Page.Resources>
<AutoSuggestBox Name="SearchAutoSuggestBox"
PlaceholderText="Search by keywords"
QueryIcon="Find">
<interactivity:Interaction.Behaviors>
<core:EventTriggerBehavior EventName="QuerySubmitted">
<core:InvokeCommandAction
Command="{x:Bind ViewModel.SearchCommand}"
InputConverter="{StaticResource ArgsConverter}" />
</core:EventTriggerBehavior>
</interactivity:Interaction.Behaviors>
</AutoSuggestBox>
Finally in your viewmodel change your command to accept a string as parameter. So you would have the following in your vm:
public DelegateCommand<string> SearchCommand { get; }
public MainPageViewModel()
{
SearchCommand = new DelegateCommand<string>(ExecuteMethod);
}
private void ExecuteMethod(string o)
{
// CODE HERE
}
You can bind the search string (Text property) to a view model property and the events to parameter-less methods. This way the view model wont have to deal with UI objects:
XAML:
<AutoSuggestBox Header="What's your name?"
TextChanged="{x:Bind ViewModel.FilterUsuals}"
QuerySubmitted="{x:Bind ViewModel.ProcessQuery}"
SuggestionChosen="{x:Bind ViewModel.ProcessChoice}"
ItemsSource="{x:Bind ViewModel.Usuals, Mode=OneWay}"
Text="{x:Bind ViewModel.SearchText, Mode=TwoWay}"
QueryIcon="Find" />
Code behind:
public class MainPageViewModel : SomeViewModelBaseClass
{
/* Boilerplate code and constructor not included */
private string _SearchText;
public string SearchText {/* getter and setter INotyfyPropertyChange compliant */ }
private List<string> _Usuals; // Initialized on constructor
public string Usuals {/* getter and setter INotyfyPropertyChange compliant */ }
public void FilterUsuals()
{
// the search string is in SearchText Example:
Usuals = _UsualsStore.Where(u => u.Contains(_SearchText.ToLower())).ToList();
}
public void ProcessQuery() { /* TODO - search string is in SearchText */ }
public void ProcessChoice() { /* TODO - search string is in SearchText */ }
}
If you don't mind doing non pure MVVM way.
MainPage.xaml :
<AutoSuggestBox Name="SearchAutoSuggestBox"
PlaceholderText="Search by keywords"
QueryIcon="Find" QuerySubmitted="{x:Bind ViewModel.SearchQuerySubmitted}" IsEnabled="{x:Bind ViewModel.CanExecuteSearchCommand, Mode=TwoWay}"
>
</AutoSuggestBox>
MainPageViewModel.cs :
public class MainPageViewModel : INotifyPropertyChanged
{
private bool _canExecuteSearchCommand;
public MainPageViewModel()
{
this.CanExecuteSearchCommand = true;
}
public bool CanExecuteSearchCommand
{
get { return _canExecuteSearchCommand; }
set
{
bool changed = _canExecuteSearchCommand != value;
_canExecuteSearchCommand = value;
if(changed)
this.OnPropertyChanged();
}
}
public void SearchQuerySubmitted(AutoSuggestBox sender, AutoSuggestBoxQuerySubmittedEventArgs args)
{
// Just example disabling SearchBox
this.CanExecuteSearchCommand = false;
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
MainPage.cs :
MainPageViewModel ViewModel = new MainPageViewModel();
UWP Binding Command/Delegate to AutoSuggestBox in MVVM
For UWP Mobile Application
Make a DelegateCommand class
public class DelegateCommand<T> : ICommand
{
private readonly Action<T> executeAction;
Func<object, bool> canExecute;
public event EventHandler CanExecuteChanged;
public DelegateCommand(Action<T> executeAction)
: this(executeAction, null)
{
//var a = ((Page)(((Func<object, bool>)(executeAction.Target)).Target)).Name;
//((ViewModel.VMBranchSelection)(executeAction.Target)).;
}
public DelegateCommand(Action<T> executeAction, Func<object, bool> canExecute)
{
this.executeAction = executeAction;
this.canExecute = canExecute;
}
public bool CanExecute(object parameter)
{
return canExecute == null ? true : canExecute(parameter);
}
public void Execute(object parameter)
{
executeAction((T)parameter);
}
public void RaiseCanExecuteChanged()
{
EventHandler handler = this.CanExecuteChanged;
if (handler != null)
{
handler(this, new EventArgs());
}
}
}
In View Model
public ICommand SuggessionSelectCity_QuerySubmitted
{
get { return new DelegateCommand<AutoSuggestBoxQuerySubmittedEventArgs>(this.SuggessionSelectCityQuerySubmitted); }
}
private void SuggessionSelectCityQuerySubmitted(AutoSuggestBoxQuerySubmittedEventArgs obj)
{
if (obj.ChosenSuggestion != null)
{
AutosuggestionTextBoxName.Text = ((ModelName) (obj.ChosenSuggestion)).Model's Property name;
//or
AutosuggestionTextBoxName.Text =(obj.ChosenSuggestion).property name
}
else
{
}
}
In XAML Code
<AutoSuggestBox Grid.Column="1" x:Name="SuggessionSelectCity"
PlaceholderText="Search by keywords" QueryIcon="Find"
ItemsSource="{Binding PApplicantCityList}"
HorizontalAlignment="Center" VerticalAlignment="Center" DisplayMemberPath="Description" Width="250" Height="45">
<Interactivity:Interaction.Behaviors>
<Core:EventTriggerBehavior EventName="TextChanged">
<Core:EventTriggerBehavior.Actions>
<Core:InvokeCommandAction Command="{Binding SuggessionSelectCityTextChange}"/>
</Core:EventTriggerBehavior.Actions>
</Core:EventTriggerBehavior>
<Core:EventTriggerBehavior EventName="QuerySubmitted">
<Core:EventTriggerBehavior.Actions>
<Core:InvokeCommandAction Command="{Binding SuggessionSelectCity_QuerySubmitted}"/>
</Core:EventTriggerBehavior.Actions>
</Core:EventTriggerBehavior>
<Core:EventTriggerBehavior EventName="SuggestionChosen">
<Core:EventTriggerBehavior.Actions>
<Core:InvokeCommandAction Command="{Binding SuggessionSelectCitySuggestionChosen}"/>
</Core:EventTriggerBehavior.Actions>
</Core:EventTriggerBehavior>
</Interactivity:Interaction.Behaviors>
</AutoSuggestBox>
</Grid>
Create a list in View Model for Autosuggestion TextBox Itemssource
private ObservableCollection<ResultMasterModel> ApplicantCityList;
public ObservableCollection<ResultMasterModel> PApplicantCityList
{
get { return ApplicantCityList; }
set { this.SetProperty(ref this.ApplicantCityList, value); }
}
add some hard code value in above list
Create a Model In Model Folder
public class ResultMasterModel
{
public string Code { get; set; }
public string Description { get; set; }
}