Hallo Peter,
Danke für deine Antwort.
Diese eine Instanz wird über Singleton realisiert, oder gibt es dort eine bessere Lösung die ich noch nicht gesehen habe?
Momentan habe ich eine Listview mit einer List realisiert (wegen EF .ToList()), macht es Sinn dies auf Observable Collection zu ändern? Habe dort noch nicht so richtig den Unterschied festgestellt (ich weiß es gibt 1000'e Tutorials dazu). Gibt es eine Möglichkeit
das wenn ich das Model mit x:Bind in XAML binde den Text eines Elements live zu aktualisieren und die Elemente zu sortieren? Mit {Binding Update...Trigger=PropertyChanged} klappt es (nach Optimierungsleitpfaden soll x:Bind verwendet werden).
Hier Mein Code:
XAML:
<Page
x:Class="UI.Pages.Tasks"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:UI.Pages"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:views="using:UI.Views"
xmlns:models="using:UI.Models"
xmlns:formatter="using:UI.Formatter"
mc:Ignorable="d"
d:DesignWidth="900">
<Page.Resources>
<formatter:ConvertListItemStateToFont x:Key="ConvertStateToFontStyle" />
<formatter:ConvertItemUsageToVisibility x:Key="ConvertUsageToVisibility" />
<formatter:ConvertSelectedItemToVisibility x:Key="ConvertSelectedItemToVisivility" />
<x:String x:Key="mus">fgh</x:String>
</Page.Resources>
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Grid.RowDefinitions>
<RowDefinition Height="100"/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="380"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock HorizontalAlignment="Left" Margin="10,10,0,0" TextWrapping="Wrap" Text="Aufgaben" FontWeight="Bold" VerticalAlignment="Top"/>
<TextBlock Text="Legen Sie neue Aufgaben an oder ändern Sie diese." Margin="10,35,10,0" VerticalAlignment="Top" Grid.ColumnSpan="2" />
<StackPanel Margin="10,60,10,0" VerticalAlignment="Top" Orientation="Horizontal">
<TextBox HorizontalAlignment="Left" TextWrapping="NoWrap" Text="{Binding TaskSearch, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Width="275" PlaceholderText="Suchen" AutomationProperties.LandmarkType="Search" />
<Button x:Name="ButtonAdd" Content="Anlegen" Margin="10,0,0,0" HorizontalAlignment="Right" Width="75" Click="ButtonAdd_Click" />
</StackPanel>
<ListView x:Name="ListTasks" Margin="10,10,10,10" IsItemClickEnabled="True" SelectionChanged="ListTasks_SelectionChanged" ItemsSource="{x:Bind _TaskViewModel.Tasks, Mode=OneWay}" SelectedValuePath="Id" Grid.Row="1" SelectedItem="{x:Bind _TaskViewModel.TaskSelected, Mode=TwoWay}">
<ListView.ItemContainerTransitions>
<TransitionCollection/>
</ListView.ItemContainerTransitions>
<ListView.ItemTemplate>
<DataTemplate x:DataType="models:Order">
<TextBlock Text="{x:Bind Name, Mode=OneWay}" FontStyle="{x:Bind Active, Converter={StaticResource ConvertStateToFontStyle}, Mode=OneWay}" FontWeight="{x:Bind Active, Converter={StaticResource ConvertStateToFontStyle}, Mode=OneWay}" />
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<StackPanel Grid.Column="1" Margin="10" VerticalAlignment="Top" Grid.Row="1" Width="350" HorizontalAlignment="Left" Visibility="{x:Bind _TaskViewModel.TaskSelected, Converter={StaticResource ConvertSelectedItemToVisivility}, Mode=OneWay}">
<TextBox x:Name="TextBoxTaskName" TextWrapping="NoWrap" Text="{x:Bind _TaskViewModel.TaskSelected.Name, Mode=TwoWay}" VerticalAlignment="Top" Header="Name der Aufgabe" MaxLength="32" />
<!--<TextBox x:Name="TextBoxTaskName" TextWrapping="NoWrap" Text="{Binding Path=SelectedItem.Name, ElementName=ListTasks, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" VerticalAlignment="Top" Header="Name der Aufgabe" MaxLength="32" LostFocus="{x:Bind _TaskViewModel.SaveItem}"/>-->
<ToggleSwitch Margin="0,10" HorizontalAlignment="Left" VerticalAlignment="Top" Header="Aufgabe aktiv?" IsOn="{x:Bind _TaskViewModel.TaskSelected.Active, Mode=TwoWay}" />
<!--<ToggleSwitch Margin="0,10" HorizontalAlignment="Left" VerticalAlignment="Top" Header="Aufgabe aktiv?" IsOn="{Binding Path=SelectedItem.Active, ElementName=ListTasks, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" Toggled="{x:Bind _TaskViewModel.SaveItem}"/>-->
<Button Content="Löschen" HorizontalAlignment="Left" VerticalAlignment="Top" Visibility="{x:Bind _TaskViewModel.TaskSelected.Used, Converter={StaticResource ConvertUsageToVisibility}, FallbackValue=Collapsed,Mode=OneWay}">
<Button.Flyout>
<Flyout x:Name="FlyoutDelete">
<StackPanel>
<TextBlock TextWrapping="Wrap" Text="Wollen Sie diese Aufgabe löschen?" Width="320"/>
<Button Margin="0,10,0,0" Content="Löschen" Click="ButtonFlyoutDelete_Click" />
</StackPanel>
</Flyout>
</Button.Flyout>
</Button>
<Button Content="Löschen" HorizontalAlignment="Left" VerticalAlignment="Top" Click="{x:Bind _TaskViewModel.Remove}" Visibility="{x:Bind _TaskViewModel.TaskSelected.Used, Converter={StaticResource ConvertUsageToVisibility}, ConverterParameter=invert, FallbackValue=Visible, Mode=OneWay}"/>
</StackPanel>
</Grid>
</Page>
MVVM:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Windows.Input;
using System.Threading.Tasks;
using UI.Models
namespace UI.ViewModels
{
public class TaskSettingsViewModel : demo
{
public TaskSettingsViewModel()
{
updateTasks();
}
private List<Order> _Tasks = new List<Order>();
public List<Order> Tasks { get => _Tasks; set => SetProperty(ref _Tasks, value); }
private Order _TaskSelected;
public Order TaskSelected
{
get => _TaskSelected; set
{
if (value != TaskSelected)
{
SetProperty(ref _TaskSelected, value);
}
}
}
public void SaveItem()
{
if (TaskSelected == null)
return;
Data.Task item; Order change = TaskSelected;
using (Context db = new Context())
{
item = db.Tasks.FirstOrDefault(w => w.TaskId == change.Id);
if (item != null)
{
if (item.Title != change.Name || item.Valid != change.Active)
{
item.Title = change.Name;
item.Valid = change.Active;
db.Update(item);
db.SaveChanges();
updateTasks();
}
}
}
TaskSelected = Tasks.FirstOrDefault(w => w.Id == change.Id);
}
public void updateTasks()
{
using (Context db = new Context())
{
//Tasks = db.Tasks.Where(w => w.TaskId != 1 && w.Title.ToLower().Contains(TaskSearch.ToLower())).OrderBy(o => o.Title.ToLower()).Select(s => new Order() { Active = s.Valid, Id = s.TaskId, Name = s.Title, Used = (s.Times.Count == 0 ? false : true) }).ToList();
Tasks = db.Tasks.Where(w => w.TaskId != 1 && w.Title.ToLower().Contains(TaskSearch.ToLower())).OrderBy(o => o.Title.ToLower()).Select(s => new Order(s.TaskId, s.Title, s.Valid, (s.Times.Count == 0 ? false : true))).ToList();
}
MainViewModel.Instance.Tasks.Clear();
}
private string _TaskSearch = String.Empty;
public string TaskSearch
{
get => _TaskSearch; set
{
if (value != TaskSearch)
{
SetProperty(ref _TaskSearch, value);
updateTasks();
}
}
}
public void Remove()
{
using (Context db = new Context())
{
db.Tasks.Remove(db.Tasks.FirstOrDefault(w => w.TaskId == TaskSelected.Id));
db.SaveChanges();
updateTasks();
}
}
public void add()
{
var a = new Data.Task() { Title = "", Valid = false };
using (Context db = new Context())
{
db.Tasks.Add(a);
db.SaveChanges();
updateTasks();
}
TaskSelected = Tasks.FirstOrDefault(w => w.Id == a.TaskId);
}
}
public class demo : NotificationBase, INotifyCollectionChanged
{
public event NotifyCollectionChangedEventHandler CollectionChanged;
public virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
{
if (CollectionChanged != null)
{
CollectionChanged(this, e);
}
}
}
public class NotificationBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
// SetField (Name, value); // where there is a data member
protected bool SetProperty<T>(ref T field, T value, [CallerMemberName] String property
= null)
{
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
RaisePropertyChanged(property);
return true;
}
// SetField(()=> somewhere.Name = value; somewhere.Name, value)
// Advanced case where you rely on another property
protected bool SetProperty<T>(T currentValue, T newValue, Action DoSet,
[CallerMemberName] String property = null)
{
if (EqualityComparer<T>.Default.Equals(currentValue, newValue)) return false;
DoSet.Invoke();
RaisePropertyChanged(property);
return true;
}
protected void RaisePropertyChanged(string property)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
}
public class NotificationBase<T> : NotificationBase where T : class, new()
{
protected T This;
public static implicit operator T(NotificationBase<T> thing) { return thing.This; }
public NotificationBase(T thing = null)
{
This = (thing == null) ? new T() : thing;
}
}
public class CommandHandler : ICommand
{
public event EventHandler CanExecuteChanged;
private Action _action;
public CommandHandler(Action action)
{
this._action = action;
}
public bool CanExecute(object parameter)
{
return true;
}
public void Execute(object parameter)
{
this._action();
}
}
}
namespace UI.Models {
public class Order : NotificationBase
{
public int Id { get; set; }
private string _Name;
public string Name { get => _Name; set => SetProperty(ref _Name, value); }
private bool _Active;
public bool Active { get => _Active; set => SetProperty(ref _Active, value); }
public bool Used { get; set; }
public Order(int Id, string Name, bool Active, bool Used)
{
this.Id = Id;
this.Name = Name;
this.Active = Active;
this.Used = Used;
PropertyChanged += Order_PropertyChanged;
}
public Order()
{
}
private void Order_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
using (Context db = new Context())
{
Data.Task item = db.Tasks.FirstOrDefault(w => w.TaskId == Id);
if (item.Title != Name || item.Valid != Active)
{
item.Title = Name;
item.Valid = Active;
db.Update(item);
db.SaveChanges();
}
}
}
}
}
Bzw. was ist an meinem ViewModel zu verbessern oder habe ich etwas falsch implementiert?
Vielen Dank
A.Kuller
