Xamarin Forms ListView Command to VM with EventToCommandBehavior

Xamarin Forms ListView Command to VM with EventToCommandBehavior - c#

So i wanted to use commanding inside my ViewModel so i can interact with my listview. I looked at the forms example of EventToCommandBehavior. I tried to replicate the code inside my project but for some reason i can't get it to work.
What i got is this:
BehaviorBase.cs inside Sogeti.Core.Behaviors folder
using System;
using Xamarin.Forms;
namespace Sogeti.Core
{
public class BehaviorBase<T> : Behavior<T> where T : BindableObject
{
public T AssociatedObject { get; private set; }
protected override void OnAttachedTo(T bindable)
{
base.OnAttachedTo(bindable);
AssociatedObject = bindable;
if (bindable.BindingContext != null)
{
BindingContext = bindable.BindingContext;
}
bindable.BindingContextChanged += OnBindingContextChanged;
}
protected override void OnDetachingFrom(T bindable)
{
base.OnDetachingFrom(bindable);
bindable.BindingContextChanged -= OnBindingContextChanged;
AssociatedObject = null;
}
void OnBindingContextChanged(object sender, EventArgs e)
{
OnBindingContextChanged();
}
protected override void OnBindingContextChanged()
{
base.OnBindingContextChanged();
BindingContext = AssociatedObject.BindingContext;
}
}
}
EventToCommandBehavior.cs inside Sogeti.Core.Behaviors folder
using System;
using System.Reflection;
using System.Windows.Input;
using Xamarin.Forms;
namespace Sogeti.Core
{
public class EventToCommandBehavior : BehaviorBase<View>
{
Delegate eventHandler;
public static readonly BindableProperty EventNameProperty = BindableProperty.Create("EventName", typeof(string), typeof(EventToCommandBehavior), null, propertyChanged: OnEventNameChanged);
public static readonly BindableProperty CommandProperty = BindableProperty.Create("Command", typeof(ICommand), typeof(EventToCommandBehavior), null);
public static readonly BindableProperty CommandParameterProperty = BindableProperty.Create("CommandParameter", typeof(object), typeof(EventToCommandBehavior), null);
public static readonly BindableProperty InputConverterProperty = BindableProperty.Create("Converter", typeof(IValueConverter), typeof(EventToCommandBehavior), null);
public string EventName
{
get { return (string)GetValue(EventNameProperty); }
set { SetValue(EventNameProperty, value); }
}
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
public object CommandParameter
{
get { return GetValue(CommandParameterProperty); }
set { SetValue(CommandParameterProperty, value); }
}
public IValueConverter Converter
{
get { return (IValueConverter)GetValue(InputConverterProperty); }
set { SetValue(InputConverterProperty, value); }
}
protected override void OnAttachedTo(View bindable)
{
base.OnAttachedTo(bindable);
RegisterEvent(EventName);
}
protected override void OnDetachingFrom(View bindable)
{
DeregisterEvent(EventName);
base.OnDetachingFrom(bindable);
}
void RegisterEvent(string name)
{
if (string.IsNullOrWhiteSpace(name))
{
return;
}
EventInfo eventInfo = AssociatedObject.GetType().GetRuntimeEvent(name);
if (eventInfo == null)
{
throw new ArgumentException(string.Format("EventToCommandBehavior: Can't register the '{0}' event.", EventName));
}
MethodInfo methodInfo = typeof(EventToCommandBehavior).GetTypeInfo().GetDeclaredMethod("OnEvent");
eventHandler = methodInfo.CreateDelegate(eventInfo.EventHandlerType, this);
eventInfo.AddEventHandler(AssociatedObject, eventHandler);
}
void DeregisterEvent(string name)
{
if (string.IsNullOrWhiteSpace(name))
{
return;
}
if (eventHandler == null)
{
return;
}
EventInfo eventInfo = AssociatedObject.GetType().GetRuntimeEvent(name);
if (eventInfo == null)
{
throw new ArgumentException(string.Format("EventToCommandBehavior: Can't de-register the '{0}' event.", EventName));
}
eventInfo.RemoveEventHandler(AssociatedObject, eventHandler);
eventHandler = null;
}
void OnEvent(object sender, object eventArgs)
{
if (Command == null)
{
return;
}
object resolvedParameter;
if (CommandParameter != null)
{
resolvedParameter = CommandParameter;
}
else if (Converter != null)
{
resolvedParameter = Converter.Convert(eventArgs, typeof(object), null, null);
}
else
{
resolvedParameter = eventArgs;
}
if (Command.CanExecute(resolvedParameter))
{
Command.Execute(resolvedParameter);
}
}
static void OnEventNameChanged(BindableObject bindable, object oldValue, object newValue)
{
var behavior = (EventToCommandBehavior)bindable;
if (behavior.AssociatedObject == null)
{
return;
}
string oldEventName = (string)oldValue;
string newEventName = (string)newValue;
behavior.DeregisterEvent(oldEventName);
behavior.RegisterEvent(newEventName);
}
}
}
SelectedItemEventArgsToSelectedItemConverter.cs inside Sogeti.Core.Converters folder
using System;
using System.Globalization;
using Xamarin.Forms;
namespace Sogeti.Core
{
public class SelectedItemEventArgsToSelectedItemConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var eventArgs = value as SelectedItemChangedEventArgs;
return eventArgs.SelectedItem;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
MyViewModel inside Sogeti.Core.ViewModel folder
using System;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;
using System.Collections;
using System.Collections.Generic;
using System.Windows.Input;
using Xamarin.Forms;
using System.Diagnostics;
using System.Threading.Tasks;
namespace Sogeti.Core
{
public class SogetistDetailsViewModel : SimpleViewModel
{
private Sogetist sogetist;
public ICommand ViewSelectedCommand { get; private set; }
public string FullName
{
get
{
return sogetist.Name + " " + sogetist.LastName;
}
}
public string Introduction
{
get
{
return sogetist.Introduction;
}
set
{
if (sogetist.Introduction != value)
{
sogetist.Introduction = value;
RaisePropertyChanged(() => Introduction);
}
}
}
public string Function
{
get
{
return sogetist.Function.Name;
}
set
{
if (value != sogetist.Function.Name)
{
sogetist.Function.Name = value;
RaisePropertyChanged(() => Function);
}
}
}
public string Skills
{
get
{
List<string> skills = sogetist.Skill.Select(x => x.Name).ToList();
return string.Join(", ", skills);
}
}
public string Image
{
get
{
return sogetist.Image;
}
set
{
if (value != sogetist.Image)
{
sogetist.Image = value;
RaisePropertyChanged(() => Image);
}
}
}
public SogetistDetailsViewModel() : this(new Sogetist())
{
}
public SogetistDetailsViewModel(Sogetist sogetist)
{
this.sogetist = sogetist;
Image = this.sogetist.Image;
ViewSelectedCommand = new Command<Sogetist>(OnViewSelected);
}
void OnViewSelected(Sogetist obj)
{
String a = obj.Name;
}
}
}
MainPage.Xaml inside Sogeti namespace
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage x:Class="Sogeti.MainPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:core="clr-namespace:Sogeti.Core;assembly=Sogeti.Core"
Title="Sogetist list">
<ContentPage.Resources>
<ResourceDictionary>
<core:SelectedItemEventArgsToSelectedItemConverter x:Key="SelectedItemConverter" />
</ResourceDictionary>
</ContentPage.Resources>
<ListView x:Name="listView"
CachingStrategy="RecycleElement"
Footer="{Binding Count}"
IsPullToRefreshEnabled="True"
ItemsSource="{Binding .}">
<ListView.Behaviors>
<core:EventToCommandBehavior EventName="ItemSelected" Command="{Binding ViewSelectedCommand}" Converter="{StaticResource SelectedItemConverter}" />
</ListView.Behaviors>
<ListView.FooterTemplate>
<DataTemplate>
<ContentView BackgroundColor="#FF4411" Padding="0,5">
<Label FontSize="Micro"
HorizontalTextAlignment="Center"
Text="{Binding .,
StringFormat='{0} Sogetists'}"
TextColor="White"
VerticalTextAlignment="Center">
<Label.Triggers>
<DataTrigger Binding="{Binding .}"
TargetType="Label"
Value="1">
<Setter Property="Text" Value="{Binding ., StringFormat='{0} Sogetist'}" />
</DataTrigger>
</Label.Triggers>
</Label>
</ContentView>
</DataTemplate>
</ListView.FooterTemplate>
<ListView.ItemTemplate>
<DataTemplate>
<ImageCell Detail="{Binding Function}"
ImageSource="{Binding Image}"
Text="{Binding FullName}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ContentPage>
MainPage.Xaml.cs
using Xamarin.Forms;
using Sogeti.Core;
using System.Collections.Generic;
using System.Threading.Tasks;
using System;
using System.Collections.ObjectModel;
using System.Linq;
namespace Sogeti
{
public partial class MainPage : ContentPage
{
private readonly BackendlessHandler backendless = new BackendlessHandler();
public ObservableCollection<SogetistDetailsViewModel> Sogetists { get; private set; }
public MainPage()
{
InitializeComponent();
}
protected override async void OnAppearing()
{
base.OnAppearing();
if (Sogetists == null)
{
await LoadSogetistsAsync();
BindingContext = Sogetists;
}
}
private async Task LoadSogetistsAsync()
{
IsBusy = true;
try
{
var sogetistDetailsViewModelList = (await backendless.GetAllSogetistsAsync()).OrderBy(x => x.Name).Select(x => new SogetistDetailsViewModel(x));
Sogetists = new ObservableCollection<SogetistDetailsViewModel>(sogetistDetailsViewModelList);
}
catch (Exception ex)
{
await this.DisplayAlert("Error", "Failed to download sogetists: " + ex.Message, "OK");
}
finally
{
IsBusy = false;
}
}
}
}

Your problem is the binding to command you defined.
There is no ViewModel behind your MainPage, instead, currently you just write the logic in the View itself. I would suggest to use pure MVVM approach in order to simplify your solution and for this you need to:
Create a MainViewModel
Move all the logic from MainPage in to MainViewModel
Set the BindingContext of the MainPage to MainViewModel
So your MainViewModel will contain a list of ObservalbeCollection< SogetistDetailsViewModel> & your command with SogetistDetailsViewModel parameter defined only once.

I suggest to use this plugin. (here the source)
You can find a sample here, in my GitHub repository.
This is the XAML
<?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:local="clr-namespace:TestListViewMultiSelectItems"
xmlns:behaviors="clr-namespace:Behaviors;assembly=Behaviors"
x:Class="TestListViewMultiSelectItems.TestListViewMultiSelectItemsPage">
<ContentPage.Resources>
<ResourceDictionary>
<local:SelectedItemEventArgsToSelectedItemConverter x:Key="SelectedItemConverter" />
</ResourceDictionary>
</ContentPage.Resources>
<StackLayout Padding="20,20,20,20">
<Label Text = "{Binding SelectedItemsCounter, StringFormat='SelectedItems\' Counter {0}'}" HorizontalTextAlignment = "Center"/>
<ListView ItemsSource="{Binding Items}">
<ListView.Behaviors>
<behaviors:EventHandlerBehavior EventName="ItemTapped">
<behaviors:InvokeCommandAction Command="{Binding ItemTappedCommand}"/>
</behaviors:EventHandlerBehavior>
</ListView.Behaviors>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding DisplayName}" TextColor = "Fuchsia" HorizontalOptions = "StartAndExpand"/>
<BoxView Color="Fuchsia" IsVisible="{Binding Selected}" HorizontalOptions = "End"/>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</StackLayout>
</ContentPage>
In this sample I use an ItemTappedCommand.
In my ViewModel
ItemTappedCommand = new Command((object model) => {
if (model != null && model is ItemTappedEventArgs) {
if (!((Model)((ItemTappedEventArgs)model).Item).Selected)
SelectedItemsCounter++;
else
SelectedItemsCounter--;
((Model)((ItemTappedEventArgs)model).Item).Selected = !((Model)((ItemTappedEventArgs)model).Item).Selected;
}
});

Related

Event to Command behavior doesn't execute Command

I'm using Event to Command Behavior found here to implement a command in the ItemTapped event of a ListView. I copied the EventToCommandBehavior and BehaviorBase classes to my project.
Here is my View
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:AppVentas.Behaviors"
mc:Ignorable="d"
x:Class="AppVentas.Views.UsuariosView">
<ContentPage.Content>
<ListView HasUnevenRows="True"
ItemsSource="{Binding Usuarios}"
ItemTapped="ListView_ItemTapped">
<ListView.Behaviors>
<local:EventToCommandBehavior
EventName="ItemTapped"
Command="{Binding OpenChatCommand}"/>
</ListView.Behaviors>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<Label Text="{Binding Nombre}"/>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ContentPage.Content>
And my ViewModel
public class UsuariosViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public ObservableCollection<Usuarios> Usuarios { get; set; }
public ICommand OpenChatCommand { get; set; }
private UsuarioController usuarioController = new UsuarioController();
public UsuariosViewModel()
{
Usuarios = new ObservableCollection<Usuarios>(usuarioController.Get().Where(i => i.Token == null));
OpenChatCommand = new Command<Usuarios>(OpenChat);
}
void OpenChat(Usuarios usuario)
{
//trying to do something
}
}
The problem is that OpenChatCommand never gets executed, the method OnEvent of the EventToCommandBehavior class do gets executed but the line Command.Execute (resolvedParameter); just doesn't do anything.
I'm using the PropertyChanged.Fody package if that's of any use.
Any help is appreciated, thanks.

From Reusable EventToCommandBehavior, I suggest you can use Converter in your code, I create simple that you can take a look:
<ContentPage
x:Class="Listviewsample.MainPage"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:converter="clr-namespace:Listviewsample"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:local="clr-namespace:Listviewsample.Behaviors"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<ContentPage.Resources>
<converter:TappedItemConverter x:Key="converter1" />
</ContentPage.Resources>
<StackLayout>
<!-- Place new controls here -->
<ListView
x:Name="listview1"
HasUnevenRows="True"
ItemsSource="{Binding images}">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout>
<Label Text="{Binding title}" />
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
<ListView.Behaviors>
<local:EventToCommandBehavior
Command="{Binding command1}"
Converter="{StaticResource converter1}"
EventName="ItemTapped" />
</ListView.Behaviors>
</ListView>
</StackLayout>
public partial class MainPage : ContentPage
{
public ObservableCollection<imagemodel> images { get; set; }
public Command command1 { get; set; }
public MainPage()
{
InitializeComponent();
images = new ObservableCollection<imagemodel>()
{
new imagemodel(){title="image 1"},
new imagemodel(){title="image 2"},
new imagemodel(){title="image 3"}
};
command1 = new Command<imagemodel>(commandpage);
this.BindingContext = this;
}
private void commandpage(imagemodel m)
{
Console.WriteLine("the image model title is {0}",m.title.ToString());
}
}
public class imagemodel
{
public string title { get; set; }
}
The BehaviorBase.cs:
public class BehaviorBase<T> : Behavior<T> where T : BindableObject
{
public T AssociatedObject { get; private set; }
protected override void OnAttachedTo(T bindable)
{
base.OnAttachedTo(bindable);
AssociatedObject = bindable;
if (bindable.BindingContext != null)
{
BindingContext = bindable.BindingContext;
}
bindable.BindingContextChanged += OnBindingContextChanged;
}
protected override void OnDetachingFrom(T bindable)
{
base.OnDetachingFrom(bindable);
bindable.BindingContextChanged -= OnBindingContextChanged;
AssociatedObject = null;
}
void OnBindingContextChanged(object sender, EventArgs e)
{
OnBindingContextChanged();
}
protected override void OnBindingContextChanged()
{
base.OnBindingContextChanged();
BindingContext = AssociatedObject.BindingContext;
}
}
The EventToCommandBehavior.cs:
public class EventToCommandBehavior : BehaviorBase<View>
{
Delegate eventHandler;
public static readonly BindableProperty EventNameProperty = BindableProperty.Create("EventName", typeof(string), typeof(EventToCommandBehavior), null, propertyChanged: OnEventNameChanged);
public static readonly BindableProperty CommandProperty = BindableProperty.Create("Command", typeof(ICommand), typeof(EventToCommandBehavior), null);
public static readonly BindableProperty CommandParameterProperty = BindableProperty.Create("CommandParameter", typeof(object), typeof(EventToCommandBehavior), null);
public static readonly BindableProperty InputConverterProperty = BindableProperty.Create("Converter", typeof(IValueConverter), typeof(EventToCommandBehavior), null);
public string EventName
{
get { return (string)GetValue(EventNameProperty); }
set { SetValue(EventNameProperty, value); }
}
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
public object CommandParameter
{
get { return GetValue(CommandParameterProperty); }
set { SetValue(CommandParameterProperty, value); }
}
public IValueConverter Converter
{
get { return (IValueConverter)GetValue(InputConverterProperty); }
set { SetValue(InputConverterProperty, value); }
}
protected override void OnAttachedTo(View bindable)
{
base.OnAttachedTo(bindable);
RegisterEvent(EventName);
}
protected override void OnDetachingFrom(View bindable)
{
DeregisterEvent(EventName);
base.OnDetachingFrom(bindable);
}
void RegisterEvent(string name)
{
if (string.IsNullOrWhiteSpace(name))
{
return;
}
EventInfo eventInfo = AssociatedObject.GetType().GetRuntimeEvent(name);
if (eventInfo == null)
{
throw new ArgumentException(string.Format("EventToCommandBehavior: Can't register the '{0}' event.", EventName));
}
MethodInfo methodInfo = typeof(EventToCommandBehavior).GetTypeInfo().GetDeclaredMethod("OnEvent");
eventHandler = methodInfo.CreateDelegate(eventInfo.EventHandlerType, this);
eventInfo.AddEventHandler(AssociatedObject, eventHandler);
}
void DeregisterEvent(string name)
{
if (string.IsNullOrWhiteSpace(name))
{
return;
}
if (eventHandler == null)
{
return;
}
EventInfo eventInfo = AssociatedObject.GetType().GetRuntimeEvent(name);
if (eventInfo == null)
{
throw new ArgumentException(string.Format("EventToCommandBehavior: Can't de-register the '{0}' event.", EventName));
}
eventInfo.RemoveEventHandler(AssociatedObject, eventHandler);
eventHandler = null;
}
void OnEvent(object sender, object eventArgs)
{
if (Command == null)
{
return;
}
object resolvedParameter;
if (CommandParameter != null)
{
resolvedParameter = CommandParameter;
}
else if (Converter != null)
{
resolvedParameter = Converter.Convert(eventArgs, typeof(object), null, null);
}
else
{
resolvedParameter = eventArgs;
}
if (Command.CanExecute(resolvedParameter))
{
Command.Execute(resolvedParameter);
}
}
static void OnEventNameChanged(BindableObject bindable, object oldValue, object newValue)
{
var behavior = (EventToCommandBehavior)bindable;
if (behavior.AssociatedObject == null)
{
return;
}
string oldEventName = (string)oldValue;
string newEventName = (string)newValue;
behavior.DeregisterEvent(oldEventName);
behavior.RegisterEvent(newEventName);
}
}
The Converter.cs,The Command property of the behavior is data bound to the command1 property of the associated ViewModel, while the Converter property is set to the TappedItemConverter instance, which returns the Tapped item of the ListView from the ItemTappedEventArgs.
public class TappedItemConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var eventArgs = value as ItemTappedEventArgs;
return eventArgs.Item;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
Here is the sample at github, you can take a look:
https://github.com/CherryBu/Eventtocommand

Assuming your bindingcontext is correctly set to an instance of UsuariosViewModel, the issue I see here is that you are not passing the command parameter. Your command accepts a Usuarios, but you need to pass that in via the CommandParameter property on the EventToCommandBehavior.
I also notice you have ListView_ItemTapped defined, but I'm not sure what you're doing in that method. It shouldn't be required to make the command work, but maybe you're using it for something else.

When other controls is placed inside datagrid column it is not binding

I am working on datagrid sample based on this one.
<dg:DataGrid x:Name="datagrid" ItemsSource="{Binding Teams}" SelectionEnabled="True" SelectedItem="{Binding SelectedTeam}" ActiveRowColor="Red"
RowHeight="70" HeaderHeight="50" BorderColor="#CCCCCC" HeaderBackground="#E0E6F8" Focused="Datagrid_Focused"
PullToRefreshCommand="{Binding RefreshCommand}" IsRefreshing="{Binding IsRefreshing}"
>
<x:Arguments>
<ListViewCachingStrategy>RetainElement</ListViewCachingStrategy>
</x:Arguments>
<dg:DataGrid.HeaderFontSize>
<OnIdiom x:TypeArguments="x:Double">
<OnIdiom.Tablet>15</OnIdiom.Tablet>
<OnIdiom.Phone>12</OnIdiom.Phone>
</OnIdiom>
</dg:DataGrid.HeaderFontSize>
<dg:DataGrid.Columns>
<dg:DataGridColumn Title="Logo" PropertyName="Logo" Width="100" SortingEnabled="False">
<dg:DataGridColumn.CellTemplate>
<DataTemplate>
<Image Source="{Binding}" HorizontalOptions="Center" VerticalOptions="Center" Aspect="AspectFit" HeightRequest="60" />
</DataTemplate>
</dg:DataGridColumn.CellTemplate>
</dg:DataGridColumn>
<dg:DataGridColumn Title="Team" PropertyName="Name" Width="2*">
<dg:DataGridColumn.CellTemplate>
<DataTemplate>
<Grid x:Name="gridtest" BindingContext="{Binding .}">
<Grid.GestureRecognizers>
<TapGestureRecognizer Tapped="TapGestureRecognizer_Tapped"/>
</Grid.GestureRecognizers>
<Label x:Name="label1" Text="{Binding Name,Mode=TwoWay}" />
<Editor x:Name="editorTest" Completed="Editor_Completed" BindingContext="{Binding .}" Focused="Editor_Focused">
</Editor>
</Grid>
</DataTemplate>
</dg:DataGridColumn.CellTemplate>
</dg:DataGridColumn>
<dg:DataGridColumn Title="Win" PropertyName="Win" Width="0.95*"/>
<dg:DataGridColumn Title="Loose" PropertyName="Loose" Width="1*"/>
<dg:DataGridColumn PropertyName="Home">
<dg:DataGridColumn.FormattedTitle>
<FormattedString>
<Span Text="Home" ForegroundColor="Black" FontSize="13" FontAttributes="Bold"/>
<Span Text=" (win-loose)" ForegroundColor="#333333" FontSize="11" />
</FormattedString>
</dg:DataGridColumn.FormattedTitle>
</dg:DataGridColumn>
<dg:DataGridColumn Title="Percentage" PropertyName="Percentage" StringFormat="{}{0:0.00}" />
</dg:DataGrid.Columns>
</dg:DataGrid>
I have a Team model, the name what i entered in editor should be bind in that model property. In static cases it is working. How to acheive in dynamic case like,
I have add button . In add button only i am adding item to the collection Teams,
private void AddButton_Clicked(object sender, EventArgs e)
{
viewModel.Teams.Add(new Models.Team()
{
Win = 73,
Name = "",
Loose = 9,
Percentage = 0.89,
Conf = "46-6",
Div = "15-1",
Home = "39-2",
Road = "34-7",
Last10 = "8-2",
Streak = "W 4",
Logo = "gsw.png"
});
}
When editor is opened, datagrid selectedItem event is not working.and the text is not binding to the model property Name.
On clicking the Save Button, I need updated collection.
How to acheive this scenario?

Since you had used MVVM , you should handle all the logic in ViewModel. You could bind the Text of Editor in model.
<Editor Text="{Binding editorText,Mode=TwoWay}"... />
in model
define a new property
public class Team : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string property)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
string editorText;
public string EditorText
{
get
{
return editorText;
}
set
{
if(value!=null)
{
editorText = value;
OnPropertyChanged("EditorText");
}
}
}
//...
}
When editor is opened, datagrid selectedItem event is not working.
This maybe a issue of the plugin . You could set the SelectItem when the editor is focused .
Add the following class in your project
using System;
using Xamarin.Forms;
namespace xxx
{
public class BehaviorBase<T> : Behavior<T> where T : BindableObject
{
public T AssociatedObject { get; private set; }
protected override void OnAttachedTo (T bindable)
{
base.OnAttachedTo (bindable);
AssociatedObject = bindable;
if (bindable.BindingContext != null) {
BindingContext = bindable.BindingContext;
}
bindable.BindingContextChanged += OnBindingContextChanged;
}
protected override void OnDetachingFrom (T bindable)
{
base.OnDetachingFrom (bindable);
bindable.BindingContextChanged -= OnBindingContextChanged;
AssociatedObject = null;
}
void OnBindingContextChanged (object sender, EventArgs e)
{
OnBindingContextChanged ();
}
protected override void OnBindingContextChanged ()
{
base.OnBindingContextChanged ();
BindingContext = AssociatedObject.BindingContext;
}
}
}
using System;
using System.Reflection;
using System.Windows.Input;
using Xamarin.Forms;
namespace xxx
{
public class EventToCommandBehavior : BehaviorBase<View>
{
Delegate eventHandler;
public static readonly BindableProperty EventNameProperty = BindableProperty.Create ("EventName", typeof(string), typeof(EventToCommandBehavior), null, propertyChanged: OnEventNameChanged);
public static readonly BindableProperty CommandProperty = BindableProperty.Create ("Command", typeof(ICommand), typeof(EventToCommandBehavior), null);
public static readonly BindableProperty CommandParameterProperty = BindableProperty.Create ("CommandParameter", typeof(object), typeof(EventToCommandBehavior), null);
public static readonly BindableProperty InputConverterProperty = BindableProperty.Create ("Converter", typeof(IValueConverter), typeof(EventToCommandBehavior), null);
public string EventName {
get { return (string)GetValue (EventNameProperty); }
set { SetValue (EventNameProperty, value); }
}
public ICommand Command {
get { return (ICommand)GetValue (CommandProperty); }
set { SetValue (CommandProperty, value); }
}
public object CommandParameter {
get { return GetValue (CommandParameterProperty); }
set { SetValue (CommandParameterProperty, value); }
}
public IValueConverter Converter {
get { return (IValueConverter)GetValue (InputConverterProperty); }
set { SetValue (InputConverterProperty, value); }
}
protected override void OnAttachedTo (View bindable)
{
base.OnAttachedTo (bindable);
RegisterEvent (EventName);
}
protected override void OnDetachingFrom (View bindable)
{
DeregisterEvent (EventName);
base.OnDetachingFrom (bindable);
}
void RegisterEvent (string name)
{
if (string.IsNullOrWhiteSpace (name)) {
return;
}
EventInfo eventInfo = AssociatedObject.GetType ().GetRuntimeEvent (name);
if (eventInfo == null) {
throw new ArgumentException (string.Format ("EventToCommandBehavior: Can't register the '{0}' event.", EventName));
}
MethodInfo methodInfo = typeof(EventToCommandBehavior).GetTypeInfo ().GetDeclaredMethod ("OnEvent");
eventHandler = methodInfo.CreateDelegate (eventInfo.EventHandlerType, this);
eventInfo.AddEventHandler (AssociatedObject, eventHandler);
}
void DeregisterEvent (string name)
{
if (string.IsNullOrWhiteSpace (name)) {
return;
}
if (eventHandler == null) {
return;
}
EventInfo eventInfo = AssociatedObject.GetType ().GetRuntimeEvent (name);
if (eventInfo == null) {
throw new ArgumentException (string.Format ("EventToCommandBehavior: Can't de-register the '{0}' event.", EventName));
}
eventInfo.RemoveEventHandler (AssociatedObject, eventHandler);
eventHandler = null;
}
void OnEvent (object sender, object eventArgs)
{
if (Command == null) {
return;
}
object resolvedParameter;
if (CommandParameter != null) {
resolvedParameter = CommandParameter;
} else if (Converter != null) {
resolvedParameter = Converter.Convert (eventArgs, typeof(object), null, null);
} else {
resolvedParameter = eventArgs;
}
if (Command.CanExecute (resolvedParameter)) {
Command.Execute (resolvedParameter);
}
}
static void OnEventNameChanged (BindableObject bindable, object oldValue, object newValue)
{
var behavior = (EventToCommandBehavior)bindable;
if (behavior.AssociatedObject == null) {
return;
}
string oldEventName = (string)oldValue;
string newEventName = (string)newValue;
behavior.DeregisterEvent (oldEventName);
behavior.RegisterEvent (newEventName);
}
}
}
in xaml
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:xxx"
mc:Ignorable="d"
x:Name="page" // set name here
x:Class="xxx.MainPage">
<Editor.Behaviors>
<local:EventToCommandBehavior EventName="Focused" Command="{Binding Source={x:Reference page},Path=BindingContext.xxxCommand}" CommandParameter="{Binding }" />
</Editor.Behaviors>
in ViewModel
xxxCommand = new Command((model)=>{
var item = model as Team;
SelectedTeam = item;
// ...
});

Xamarin.Android Tap Gesture and Long Press Gesture not working together

I have created a custom effect by subclassing RoutingEffect in order to allow LongPressGesture for both iOS and Android in my Xamarin project.
I am using this effect on an Image in in the XAML of my shared project, and this same Image is also using a TapGesture, see code below:
<Image x:Name="TapRight" Grid.Row="4" Grid.Column="2" Source="right64"
VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand"
IsEnabled="{Binding RightEnabled}"
Opacity="{Binding RightEnabled, Converter={StaticResource OpacityConverter}}"
effects:LongPressEffect.Command="{Binding LongPressGestureCommand}"
effects:LongPressEffect.CommandParameter="{x:Static common:NavType.Right}">
<Image.GestureRecognizers>
<TapGestureRecognizer
Command="{Binding TapGestureNavCommand}"
NumberOfTapsRequired="1"
CommandParameter="{x:Static common:NavType.Right}"/>
</Image.GestureRecognizers>
<Image.Effects>
<effects:LongPressEffect></effects:LongPressEffect>
</Image.Effects>
</Image>
This works fine for iOS (I get separate functionality when I tap vs when I long press the image), however for Android, it only allows me to do Long Press, and does not execute the command for the TapGesture, any ideas on how to fix this?
NOTE: If I use a Button instead of an Image it works fine. However, I would really like to use an Image.
I have added more code below for reference:
Code for the effect in shared project:
using System.Windows.Input;
using Xamarin.Forms;
namespace MyApp.Effects
{
public class LongPressEffect : RoutingEffect
{
public LongPressEffect() : base("Xamarin.LongPressEffect")
{
}
public static readonly BindableProperty CommandProperty =
BindableProperty.CreateAttached("Command",
typeof(ICommand),
typeof(LongPressEffect),
(object)null,
propertyChanged: OnCommandChanged);
public static ICommand GetCommand(BindableObject view)
{
return (ICommand)view.GetValue(CommandProperty);
}
public static void SetCommand(BindableObject view, ICommand value)
{
view.SetValue(CommandProperty, value);
}
static void OnCommandChanged(BindableObject bindable, object oldValue, object newValue)
{
var view = bindable as View;
if (view == null)
{
return;
}
ICommand command = (ICommand)newValue;
if (command != null)
{
view.SetValue(CommandProperty, command);
}
}
public static readonly BindableProperty CommandParameterProperty =
BindableProperty.CreateAttached("CommandParameter",
typeof(object),
typeof(LongPressEffect),
(object)null,
propertyChanged: OnCommandParameterChanged);
public static object GetCommandParameter(BindableObject view)
{
return (object)view.GetValue(CommandParameterProperty);
}
public static void SetCommandParameter(BindableObject view, object value)
{
view.SetValue(CommandParameterProperty, value);
}
static void OnCommandParameterChanged(BindableObject bindable, object oldValue, object newValue)
{
var view = bindable as View;
if (view == null)
{
return;
}
object commandParameter = (object)newValue;
if (commandParameter != null)
{
view.SetValue(CommandParameterProperty, commandParameter);
}
}
}
}
Code for effect in iOS:
using System;
using System.ComponentModel;
using MyApp.Effects;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
[assembly: ResolutionGroupName("Xamarin")]
[assembly:ExportEffect (typeof(MyApp.iOS.Effects.LongPressEffect), "LongPressEffect")]
namespace MyApp.iOS.Effects
{
public class LongPressEffect : PlatformEffect
{
private readonly UILongPressGestureRecognizer _longPressGestureRecognizer;
private bool _attached;
public LongPressEffect()
{
_longPressGestureRecognizer = new UILongPressGestureRecognizer(HandleLongClick);
_attached = false;
}
protected override void OnAttached()
{
if (!_attached)
{
Container.AddGestureRecognizer(_longPressGestureRecognizer);
_attached = true;
}
}
private void HandleLongClick()
{
if (_longPressGestureRecognizer.State == UIGestureRecognizerState.Ended)
// Only execute when the press is ended.
{
var command = MyApp.Effects.LongPressEffect.GetCommand(Element);
command?.Execute(MyApp.Effects.LongPressEffect.GetCommandParameter(Element));
}
}
protected override void OnDetached()
{
if (_attached)
{
Container.RemoveGestureRecognizer(_longPressGestureRecognizer);
_attached = false;
}
}
protected override void OnElementPropertyChanged(PropertyChangedEventArgs args)
{
base.OnElementPropertyChanged(args);
}
}
}
Code for effect in Android:
using System;
using System.ComponentModel;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
[assembly: ResolutionGroupName("Xamarin")]
[assembly: ExportEffect(typeof(MyApp.Droid.Effects.LongPressEffect), "LongPressEffect")]
namespace MyApp.Droid.Effects
{
public class LongPressEffect: PlatformEffect
{
private bool _attached;
public static void Initialize() { }
public LongPressEffect()
{
_attached = false;
}
protected override void OnAttached()
{
Console.WriteLine("Invoking long click command...");
//throw new NotImplementedException();
if (!_attached) {
if (Control != null)
{
Control.LongClickable = true;
Control.LongClick += HandleLongClick;
}
_attached = true;
}
}
private void HandleLongClick(object sender, Android.Views.View.LongClickEventArgs e) {
Console.WriteLine("Invoking long click command...");
var command = MyApp.Effects.LongPressEffect.GetCommand(Element);
command?.Execute(MyApp.Effects.LongPressEffect.GetCommandParameter(Element));
}
protected override void OnDetached()
{
//throw new NotImplementedException();
if (_attached) {
if (Control != null) {
Control.LongClickable = true;
Control.LongClick -= HandleLongClick;
}
_attached = false;
}
}
protected override void OnElementPropertyChanged(PropertyChangedEventArgs args)
{
base.OnElementPropertyChanged(args);
}
}
}

This is a bug in Xamarin, more details can be found here
As a workaround I have used an ImageButton or Android and Image for IOS and made the visibility platform dependent. my XAML now looks like this:
<ImageButton x:Name="Tap" Grid.Row="4" Grid.Column="2" Source="right64"
IsEnabled="{Binding RightEnabled}"
Opacity="{Binding RightEnabled, Converter={StaticResource OpacityConverter}}"
effects:LongPressEffect.Command="{Binding LongPressGestureCommand}"
effects:LongPressEffect.CommandParameter="{x:Static common:NavType.Right}"
Command="{Binding TapGestureNavCommand}"
CommandParameter="{x:Static common:NavType.Right}">
<ImageButton.IsVisible>
<OnPlatform x:TypeArguments="x:Boolean"
iOS="False"
Android="True"/>
</ImageButton.IsVisible>
<ImageButton.Effects>
<effects:LongPressEffect></effects:LongPressEffect>
</ImageButton.Effects>
</ImageButton>
<!--Due to different behaviour on platform(s) different views were needed for different platforms.-->
<Image x:Name="TapIOS" Grid.Row="4" Grid.Column="2" Source="right64"
IsEnabled="{Binding RightEnabled}"
Opacity="{Binding RightEnabled, Converter={StaticResource OpacityConverter}}"
effects:LongPressEffect.Command="{Binding LongPressGestureCommand}"
effects:LongPressEffect.CommandParameter="{x:Static common:NavType.Right}">
<Image.IsVisible>
<OnPlatform x:TypeArguments="x:Boolean"
iOS="True"
Android="False"/>
</Image.IsVisible>
<Image.GestureRecognizers>
<TapGestureRecognizer
NumberOfTapsRequired="1"
Command="{Binding TapGestureNavCommand}"
CommandParameter="{x:Static common:NavType.Right}"/>
</Image.GestureRecognizers>
<Image.Effects>
<effects:LongPressEffect></effects:LongPressEffect>
</Image.Effects>
</Image>

Value is not updating in custom control bindable property - Xamarin forms / Prism

I created a custom control which has an Entry and a Label inside a StackControl. Then I exposed the IsEnabled property of the Entry thorough a bindable property called IsEntryEnabled which I wanted to bind to a bool property of my VM. But it never triggers. Any idea what am I doing wrong here?
Custom control - Xaml
<ContentView xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:effects="clr-namespace:VMSTablet.Effects;assembly=VMSTablet"
x:Class="VMSTablet.Controls.StandardFormEntry">
<StackLayout >
<Label Text="{Binding LabelText}" Style="{StaticResource DefaultLabelStyle}" TextColor="{StaticResource DarkGreenColor}"/>
<Entry x:Name="CustomEntry" Text="{Binding Text}"
IsEnabled="{Binding IsEntryEnabled}"
Keyboard="{Binding Keyboard}"
Behaviors="{Binding Behaviors}"
TextColor="{StaticResource DarkGreenColor}"
Placeholder="{Binding Placeholder}" Style="{StaticResource DefaultEntryStyle}" >
<Entry.Effects>
<effects:EntryBarColorEffect/>
</Entry.Effects>
</Entry>
</StackLayout>
</ContentView>
Custom control - Code Behind
namespace VMST.Controls
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class StandardFormEntry
{
public event EventHandler OnTextChanged;
public event EventHandler OnUnfocused;
public event EventHandler OnFocused;
public static readonly BindableProperty PlaceholderProperty =
BindableProperty.Create("Placeholder", typeof(string), typeof(StandardFormEntry), string.Empty);
public static readonly BindableProperty LabelTextProperty =
BindableProperty.Create("LabelText", typeof(string), typeof(StandardFormEntry), string.Empty);
public static readonly BindableProperty EntryTextProperty =
BindableProperty.Create("EntryText", typeof(string), typeof(StandardFormEntry), string.Empty);
public static BindableProperty IsEntryEnabledProperty =
BindableProperty.Create("IsEntryEnabled", typeof(bool), typeof(StandardFormEntry), true);
public static readonly BindableProperty KeyboardProperty =
BindableProperty.Create("Keyboard", typeof(Keyboard), typeof(StandardFormEntry), Xamarin.Forms.Keyboard.Default);
public static readonly BindableProperty BehaviorsProperty =
BindableProperty.Create(nameof(Behaviors), typeof(IList<Behavior>), typeof(StandardFormEntry));
public string LabelText
{
set
{
SetValue(LabelTextProperty, value);
}
get => (string)GetValue(LabelTextProperty);
}
public string EntryText
{
set => SetValue(EntryTextProperty, value);
get => (string)GetValue(EntryTextProperty);
}
public string Placeholder
{
set => SetValue(PlaceholderProperty, value);
get => (string)GetValue(PlaceholderProperty);
}
public bool IsEntryEnabled
{
set
{
SetValue(IsEntryEnabledProperty, value);
}
get => (bool)GetValue(IsEntryEnabledProperty);
}
public Keyboard Keyboard
{
set => SetValue(KeyboardProperty, value);
get => (Keyboard)GetValue(KeyboardProperty);
}
public IList<Behavior> Behaviors
{
set => SetValue(BehaviorsProperty, value);
get => (IList<Behavior>)GetValue(BehaviorsProperty);
}
public StandardFormEntry()
{
InitializeComponent();
BindingContext = this;
CustomEntry.BindingContext = this;
PropertyChanged += StandardFormEntry_PropertyChanged;
CustomEntry.Unfocused += CustomEntry_Unfocused;
CustomEntry.TextChanged += CustomEntry_TextChanged;
CustomEntry.Focused += CustomEntry_Focused;
}
private void StandardFormEntry_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == IsEntryEnabledProperty.PropertyName)
{
**//This never happens!**
}
}
protected override void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
base.OnPropertyChanged(propertyName);
}
private void CustomEntry_Focused(object sender, FocusEventArgs e)
{
OnFocused?.Invoke(sender, e);
}
private void CustomEntry_TextChanged(object sender, TextChangedEventArgs e)
{
OnTextChanged?.Invoke(sender, e);
}
private void CustomEntry_Unfocused(object sender, FocusEventArgs e)
{
OnUnfocused?.Invoke(sender, e);
}
}
}
View Model
I'm trying to trigger the IsEntryEnabled property inside the EditForm() method below. But it doesn't work.
public class PassRegistrationPageViewModel : ViewModelBase
{
public DelegateCommand AddressCommand { get; set; }
public DelegateCommand EditCommand { get; set; }
public DelegateCommand ConfirmCommand { get; set; }
public PassRegistrationPageViewModel(INavigationService navigationService) : base(navigationService)
{
Title = "Page Title";
AddressCommand = new DelegateCommand(ShowBuildings);
EditCommand = new DelegateCommand(EditForm);
ConfirmCommand = new DelegateCommand(ConfirmPass);
//IsQrVisible = false;
}
private bool _isQrVisible;
public bool IsQrVisible
{
get { return _isQrVisible; }
set {
SetProperty(ref _isQrVisible, value);
}
}
private bool _isEditingEnabled;
public bool IsEditingEnabled //Bound to the view below
{
get { return _isEditingEnabled; }
set { SetProperty(ref _isEditingEnabled, value); }
}
private string _text;
public string Text
{
get { return _text; }
set
{
SetProperty(ref _text, value);
}
}
private async void ShowBuildings()
{
await NavigationService.NavigateAsync(nameof(BuildingListPage));
}
public void EditForm()
{
IsEditingEnabled = IsEditingEnabled ? false : true;
}
public void ConfirmPass()
{
}
}
View
I bind the IsEditingEnabled property to IsEntryEnabled property in my custom control which is supposed to trigger the IsEnabled property in the Entry inside. But it never triggers.
<controls:StandardFormEntry IsEntryEnabled="{Binding IsEditingEnabled}" EntryText="{Binding Text}" LabelText="Name" Grid.Column="0" Grid.Row="3"/>

In your custom control, you need to give a name to your content view and refer the name to the source of the binding property, like below:
<ContentView xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:effects="clr-namespace:VMSTablet.Effects;assembly=VMSTablet"
x:Class="VMSTablet.Controls.StandardFormEntry"
x:Name="CustomEntryControl">
<StackLayout >
<Label Text="{Binding LabelText}" Style="{StaticResource DefaultLabelStyle}" TextColor="{StaticResource DarkGreenColor}"/>
<Entry x:Name="CustomEntry" Text="{Binding Text}"
IsEnabled="{Binding IsEntryEnabled, Source={x:Reference CustomEntryControl}}"
Keyboard="{Binding Keyboard}"
Behaviors="{Binding Behaviors}"
TextColor="{StaticResource DarkGreenColor}"
Placeholder="{Binding Placeholder}" Style="{StaticResource DefaultEntryStyle}" >
<Entry.Effects>
<effects:EntryBarColorEffect/>
</Entry.Effects>
</Entry>
</StackLayout>

WPF C# MVVM program not updating ListView

I am working on WPF, MVVM C# simple app for learning.
I do have my front-end having Table kind of structure using element ""
See "VehicalForm.xaml" below.
Below is code of my View as well as View-Model part. (I have given just necessary files. Please let me know if you need any other files)
App.xaml.cs
using Seris.ViewModels;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Windows;
namespace Seris
{
/// <summary>
/// Interaction logic for App.xaml
/// </summary>
public partial class App : Application
{
public void OnStartup(object sender, StartupEventArgs e)
{
VehicalForm vehicalForm = new VehicalForm();
vehicalForm.DataContext = new VehicalMainViewModel();
vehicalForm.Show();
}
}
}
VehicalForm.xaml
<Window x:Class="Seris.VehicalForm"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<WrapPanel Orientation="Vertical" Margin="10 " >
<Label Content="Vehical No" HorizontalAlignment="Left"/>
<TextBox Name="VehicalNo_Text" Height="23" TextWrapping="Wrap" Text="TextBox" HorizontalAlignment="Left"/>
<Label Content="Model" HorizontalAlignment="Left"/>
<TextBox Name="Model_Text" Height="23" TextWrapping="Wrap" Text="TextBox" HorizontalAlignment="Left" />
<Label Content="Manufacturing Date" HorizontalAlignment="Left"/>
<DatePicker/>
<Label Content="IU No" HorizontalAlignment="Left"/>
<TextBox Height="23" Name="IUNO_Text" TextWrapping="Wrap" Text="TextBox" HorizontalAlignment="Left"/>
<Label Content="Personnel" HorizontalAlignment="Left"/>
<ComboBox Name="Personnel_Combo" HorizontalAlignment="Left" Width="116"/>
<Separator Height="20" RenderTransformOrigin="0.5,0.5" Width="16"/>
<Button Name="Save_Button" Command="{Binding SaveToList}" Content="Save" Width="66"/>
<ListView Height="294" Width="371" >
<ListView Height="294" Width="371" ItemsSource="{Binding listItems, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" >
<ListView.View>
<GridView>
<GridViewColumn Header="Vehical No" DisplayMemberBinding="{Binding VehicalNo}" />
<GridViewColumn Header="Model" DisplayMemberBinding="{Binding Model}" />
<GridViewColumn Header="ManufacturingDate" DisplayMemberBinding="{Binding ManufacturingDate}" />
<GridViewColumn Header="IUNo" DisplayMemberBinding="{Binding IUNo}" />
<GridViewColumn Header="Personnel" DisplayMemberBinding="{Binding Personnel}" />
</GridView>
</ListView.View>
</ListView>
</WrapPanel>
VehicalForm.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace Seris
{
public partial class VehicalForm : Window
{
public VehicalForm()
{
InitializeComponent();
}
}
}
VehicalMainViewModel.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Seris.Models;
using System.Collections.ObjectModel;
using System.Windows.Input;
using Seris.Commands;
using Seris.ViewModels;
namespace Seris.ViewModels
{
public class VehicalMainViewModel : ObservableObject
{
ObservableCollection<VehicalModel> listItems = new ObservableCollection<VehicalModel>();
#region Getter-Setter
private string _VehicalNo;
public string VehicalNo
{
get { return _VehicalNo; }
set
{
if (value != _VehicalNo)
{
_VehicalNo = value.Trim();
if(OnPropertyChanged("VehicalNo"))
listItems.Add(new VehicalModel(VehicalNo, Model, ManufacturingDate, IUNo, PersonnelName));
}
}
}
private string _Model;
public string Model
{
get { return _Model; }
set
{
if (value != _Model)
{
_Model = value.Trim();
OnPropertyChanged("Model");
}
}
}
private DateTime _ManufacturingDate;
public DateTime ManufacturingDate
{
get { return _ManufacturingDate; }
set
{
if (value != _ManufacturingDate)
{
_ManufacturingDate = value;
OnPropertyChanged("ManufacturingDate");
}
}
}
private string _IUNo;
public string IUNo
{
get { return _IUNo; }
set
{
if (value != _IUNo)
{
_IUNo = value.Trim();
OnPropertyChanged("IUNo");
}
}
}
private string _PersonnelName;
public string PersonnelName
{
get { return _PersonnelName; }
set
{
if (value != _PersonnelName)
{
_PersonnelName = value.Trim();
OnPropertyChanged("PersonnelName");
}
}
}
#endregion
private ICommand _saveButton_Command;
public ICommand SaveButton_Command
{
get { return _saveButton_Command; }
set { _saveButton_Command = value; }
}
public void SaveToList(object o1)
{
listItems.Add(new VehicalModel(VehicalNo,Model,ManufacturingDate,IUNo,PersonnelName));
}
public void RemoveFromList()
{
}
public VehicalMainViewModel()
{
VehicalModel vm=new VehicalModel();
SaveButton_Command = new RelayCommand(new Action<object>(SaveToList));
}
}
}
ObservableObject.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Windows;
namespace Seris.Models
{
public abstract class ObservableObject: INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected bool OnPropertyChanged(string propertyName)
{
this.VerifyPropertyName(propertyName);
PropertyChangedEventHandler handler = PropertyChanged;
if(handler!=null)
{
if (propertyName != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
return true;
}
}
return false;
}
public void VerifyPropertyName(string propertyName)
{
if(TypeDescriptor.GetProperties(this)[propertyName]==null)
{
string msg = "Invalid Property Name: " + propertyName;
if (this.ThrowOnInvalidPropertyName)
throw new Exception(msg);
else
Debug.Fail(msg);
}
}
public bool ThrowOnInvalidPropertyName { get; set; }
}
}
VehicalModel.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace Seris.Models
{
public class VehicalModel : ObservableObject
{
#region Getter-Setter
private string _VehicalNo;
public string VehicalNo
{
get { return _VehicalNo; }
set
{
if (value != _VehicalNo)
{
_VehicalNo = value.Trim();
OnPropertyChanged("VehicalNo");
}
}
}
private string _Model;
public string Model
{
get { return _Model; }
set
{
if (value != _Model)
{
_Model = value.Trim();
OnPropertyChanged("Model");
}
}
}
private DateTime _ManufacturingDate;
public DateTime ManufacturingDate
{
get { return _ManufacturingDate; }
set
{
if (value != _ManufacturingDate)
{
_ManufacturingDate = value;
OnPropertyChanged("ManufacturingDate");
}
}
}
private string _IUNo;
public string IUNo
{
get { return _IUNo; }
set
{
if (value != _IUNo)
{
_IUNo = value.Trim();
OnPropertyChanged("IUNo");
}
}
}
private string _PersonnelName;
public string PersonnelName
{
get { return _PersonnelName; }
set
{
if (value != _PersonnelName)
{
_PersonnelName = value.Trim();
OnPropertyChanged("PersonnelName");
}
}
}
#endregion
#region Constructor
public VehicalModel(string VehicalNo, string Model, DateTime ManufacturingDate, string IUNo, string PersonnelName)
{
this.VehicalNo = VehicalNo;
this.Model = Model;
this.ManufacturingDate = ManufacturingDate;
this.IUNo = IUNo;
this.PersonnelName = PersonnelName;
}
public VehicalModel()
{
this.VehicalNo = null;
this.Model = null;
this.ManufacturingDate = DateTime.Now;
this.IUNo = null;
this.PersonnelName = null;
}
#endregion
#region Methods
#region Validate Methods
public bool Validate_VehicalNo()
{
if (matchRE(VehicalNo,"[A-Zz-z][A-Zz-z0-9]{6}"))
return true;
else
return false;
}
public bool Validate_Model()
{
if(Model!=null)
return true;
else
return false;
}
public bool Validate_ManufacturingDate()
{
return true;
}
public bool Validate_IUNo()
{
if(matchRE(IUNo,"[0-9]{10}"))
return true;
else
return false;
}
public bool Validate_PersonnelName()
{
if(matchRE(PersonnelName,"[A-Za-z]+"))
return true;
else
return false;
}
public bool matchRE(string stringToMatch, string regularExpression)
{
Regex regex = new Regex(#regularExpression);
Match match = regex.Match(stringToMatch);
if(match.Success)
return(true);
else
return(false);
}
#endregion
#endregion
}
}
What I need is
1) When I update VehicalNo, new row should be added in the table.
2) If I need to update individual elements of every row in future which should reflect in table as soon as I update , is there inbuilt facility in ListView? Or I need to use List for individual elements (i.e. VehicalNo, Model, ... ) and put in one main List keeping eye using ObservableObject?
I don't know eventhough it is being added to list as well as I have implemented INotifyPropert using ObservableObject, why its not reflecting in front-end.
Please help.

Add
public ObservableCollection ListItems {get{return listItems;}}
to you VehicalMainViewModel and change binding to
ItemsSource="{Binding ListItems}"
P.S. your listItems is private field.

ok so heres an example of the first Text box and you can follow suit on the rest:
<Window x:Class="Seris.VehicalForm"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:local="clr-namespace:Seris.ViewModels"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:VehicalMainViewModel/>
</Window.DataContext>
<Label Content="Vehical No" HorizontalAlignment="Left"/>
<TextBox Name="VehicalNo_Text" Height="23" TextWrapping="Wrap" Text="{Binding VehicalNo}" HorizontalAlignment="Left"/>
I cannot find any references at the moment but I would suggest looking at DataContext and Data Binding in WPF
EDIT
<Application x:Class="Seris.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="VehicalForm.xaml">
<Application.Resources>
</Application.Resources>
</Application>

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