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У меня есть приложение wpf, и я хочу обновить свой список, когда я изменяю значение через пользовательский интерфейс с помощью Observablecollect. Но я не понимаю, чего я ожидаю. Когда я изменю значение, я не буду обновлять свой список. View Code (Xaml)WPF MVVM и Observablecollect
<UserControl x:Class="DataWatch.View.CompareData"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:ViewModels="clr-namespace:DataWatch.ViewModel"
mc:Ignorable="d"
d:DesignHeight="340" d:DesignWidth="600">
<UserControl.DataContext>
<ViewModels:CompareViewModel/>
</UserControl.DataContext>
<Grid>
<ListView HorizontalAlignment="Left" Name="comparelistview" VerticalAlignment="Top" Width="600" Height="340" ItemsSource="{Binding DisplayData}">
<ListView.View>
<GridView>
<GridViewColumn Width="150" Header="Key"
DisplayMemberBinding="{Binding Path=Key}" />
<GridViewColumn Width="150" Header="Project Data"
DisplayMemberBinding="{Binding Path=ProjectData}" />
<GridViewColumn Width="150" Header="Import Data"
DisplayMemberBinding="{Binding Path=ImportData}"/>
<GridViewColumn Width="150" Header="State"
DisplayMemberBinding="{Binding Path=State}"/>
</GridView>
</ListView.View>
</ListView>
</Grid>
ViewModel
namespace DataWatch.ViewModel
{
public class CompareViewModel
{
private ObservableCollection<CompareDiplayData> _displayData;
public CompareViewModel()
{
_displayData = new ObservableCollection<CompareDiplayData>();
}
public ObservableCollection<CompareDiplayData> DisplayData
{
get { return _displayData; }
}
}
Модель:
namespace DataWatch.Model
{
public class CompareDiplayData : INotifyPropertyChanged
{
private string _key;
public string Key
{
set
{
_key = value;
this.Changed("Key");
}
get
{
return _key;
}
}
private string _projectData;
public string ProjectData
{
set
{
_projectData = value;
this.Changed("ProjectData");
}
get
{
return _projectData;
}
}
private string _importData;
public string ImportData
{
set
{
_importData = value;
this.Changed("ImportData");
}
get
{
return _importData;
}
}
private string _state;
public string State
{
set
{
_state = value;
this.Changed("State");
}
get
{
return _state;
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void Changed(string PropertyName)
{
if (this.PropertyChanged != null)
this.PropertyChanged(this, new PropertyChangedEventArgs(PropertyName));
}
}
}
При изменении значения в displayData, но ListView не будет обновлять данные. выпадающий контроль вид
<UserControl x:Class="DataWatch.View.SelectPanel"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:ViewModels="clr-namespace:DataWatch.ViewModel"
xmlns:AttachProperty="clr-namespace:DataWatch.AttachedProperty"
mc:Ignorable="d"
d:DesignHeight="30" d:DesignWidth="600">
<UserControl.DataContext>
<ViewModels:CompareViewModel/>
</UserControl.DataContext>
<Grid Name="good">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="150">
</ColumnDefinition>
<ColumnDefinition Width="300">
</ColumnDefinition>
<ColumnDefinition Width="150">
</ColumnDefinition>
</Grid.ColumnDefinitions>
<ComboBox Height="23" HorizontalAlignment="Left" Grid.Column="0" Grid.Row="0" Margin="15,4,6,4" x:Name="KeyComboBox" VerticalAlignment="Top" Width="120" Text="Choose Key" AttachProperty:SelectionBehavior.SelectionChanged="{Binding SelectKeyCmd}" SelectedItem="{Binding SelectedKey, Mode=TwoWay}" ItemsSource="{Binding KeyComboboxItem}"
IsEditable="true" IsReadOnly="true"
IsDropDownOpen="True" StaysOpenOnEdit="True"/>
<ComboBox Height="23" HorizontalAlignment="Left" Grid.Column="1" Grid.Row="0" Margin="90,4,6,4" Name="compareitemcomBox" VerticalAlignment="Top" Width="120" Text="Compare Item" AttachProperty:SelectionBehavior.SelectionChanged="{Binding SelectKeyCmd}" SelectedItem="{Binding SelectedComparedData, Mode=TwoWay}" ItemsSource="{Binding CompareComboboxItem}"
IsEditable="true" IsReadOnly="true"
IsDropDownOpen="True" StaysOpenOnEdit="True"/>
<ComboBox Height="23" HorizontalAlignment="Left" Grid.Column="2" Grid.Row="0" Margin="15,4,6,4" Name="display" VerticalAlignment="Top" Width="120" Text="Choose State"
IsEditable="true" IsReadOnly="true"
IsDropDownOpen="True" StaysOpenOnEdit="True"/>
</Grid>
Приложить свойству
public class SelectionBehavior
{
public static DependencyProperty SelectionChangedProperty =
DependencyProperty.RegisterAttached("SelectionChanged",
typeof(ICommand),
typeof(SelectionBehavior),
new UIPropertyMetadata(SelectionBehavior.SelectedItemChanged));
public static void SetSelectionChanged(DependencyObject target, ICommand value)
{
target.SetValue(SelectionBehavior.SelectionChangedProperty, value);
}
private static void SelectedItemChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
Selector element = target as Selector;
if (element == null) throw new InvalidOperationException("This behavior can be attached to Selector item only.");
if ((e.NewValue != null) && (e.OldValue == null))
{
element.SelectionChanged += SelectionChanged;
}
else if ((e.NewValue == null) && (e.OldValue != null))
{
element.SelectionChanged -= SelectionChanged;
}
}
private static void SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)
{
UIElement element = (UIElement)sender;
ICommand command = (ICommand)element.GetValue(SelectionBehavior.SelectionChangedProperty);
command.Execute(((Selector)sender).SelectedValue);
}
}
ViewModel
public class CompareViewModel
{
private readonly ICommand _selectKeyCmd;
private List<string> _pro_Property;
private List<string> _imp_Property;
private string selectedKey;
private ObservableCollection<string> compareComboboxItem;
private DataTable _dt;
private CompareDiplayData domObject;
private ObservableCollection<CompareDiplayData> _displayData;
public CompareViewModel()
{
_displayData = new ObservableCollection<CompareDiplayData>();
_selectKeyCmd = new RelayCommand(ComboboxChanged, ComboboxIsChanged);
}
private void ReslutData()
{_displayData =null;
if (SelectedKey != null && SelectedComparedData != null)
{
foreach (DataRow pdr in _projectDt.Rows)
{
CompareDiplayData cdd = new CompareDiplayData();
foreach (DataRow idr in _importDt.Rows)
{
if (pdr[SelectedKey].ToString() == idr[SelectedKey].ToString())
{
cdd.Key = pdr[SelectedKey].ToString();
cdd.ProjectData = pdr[SelectedComparedData].ToString();
cdd.ImportData = idr[SelectedComparedData].ToString();
if (pdr[SelectedComparedData].ToString() == idr[SelectedComparedData].ToString())
cdd.State = "Match";
else
cdd.State = "Mismatch";
_displayData.Add(cdd);
}
}
}
}
}
public ObservableCollection<CompareDiplayData> DisplayData
{
get { return _displayData; }
}
public ICommand SelectKeyCmd
{
get { return _selectKeyCmd; }
}
private void ComboboxChanged(object obj)
{
ReslutData();
}
private bool ComboboxIsChanged(object obj)
{
return true;
}`}`
по изменению вы имеете в виду, что вы создаете новую коллекцию или добавляете элементы в существующую коллекцию? – Nitin
на странице пользовательского интерфейса есть комбобокс, по defaut показать все данные, я могу использовать combobox, чтобы выбрать, какое состояние мне нравится. когда changeitem изменится, я хочу обновить listview –
, поэтому в выборе combobox вы снова создадите экземпляр displayData и заполните его правильно? можете ли вы также поделиться кодом, в котором вы это делаете? – Nitin