I made a Listbox with Checkboxes in it. The Listbox is bound to a List of my Checkbox class. Now i want to call a command from my DataContext instead of my Checkbox class when i check/uncheck the Checkbox
<ListBox Grid.Column="1" ItemsSource="{Binding Databases}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel Orientation="Horizontal"></StackPanel>
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Name}" IsChecked="{Binding IsChecked, Mode=TwoWay}" Margin="5 5 0 0" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
CheckBox class:
public class CheckBoxDatabase
{
private string name;
protected bool isChecked;
public ObservableCollection<CheckBoxDatabase> Owner;
public bool IsChecked
{
get { return isChecked; }
set
{
setzeChecked(value);
NotifyPropertyChanged();
}
}
public virtual void setzeChecked(bool value)
{
isChecked = value;
}
public string Name
{
get { return name; }
set
{
name = value;
NotifyPropertyChanged();
}
}
#region NotifyPropertyChanged
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
My main problem is if i add a command, it tells me that it is not found in the class (of course because i want it to call it in my datacontext class where i have a relaycommand. (also got another relay command independent of all this which is working where i did exactly the same)
If you want to bind to an ICommand property of the class where the Databases source collection is defined, you could use a RelativeSource:
<CheckBox Content="{Binding Name}" Command="{Binding DataContext.YourCommandProperty, RelativeSource={RelativeSource AncestorType=ListBox}}" Margin="5 5 0 0" />
Replace YourCommandProperty with the actual name of your property.
Related
I have an object that consists of a string and an array. The string populates a ComboBox and the array populates a ListView depending on the selected string value. Each line of the ListViewconsists of a TextBlock and a CheckBox.
On submit I want to be able to verify which items have been selected for further processing but there's a disconnect when using the MVVM approach. I currently have the DataContext of the submit Button binding to the ListView but only the first value is being returned upon submit (somewhere I need to save the selected values to a list I assume but I'm not sure where). I added an IsSelected property to the model which I think is the first step, but after that I've been grasping at straws.
Model
namespace DataBinding_WPF.Model
{
public class ExampleModel { }
public class Example : INotifyPropertyChanged
{
private string _name;
private string[] _ids;
private bool _isSelected;
public bool IsSelected
{
get => _isSelected;
set
{
if (_isSelected != value)
{
_isSelected = value;
RaisePropertyChanged("IsSelected");
}
}
}
public string Name
{
get => _name;
set
{
if (_name != value)
{
_name = value;
RaisePropertyChanged("Name");
}
}
}
public string[] IDs
{
get => _ids;
set
{
if (_ids != value)
{
_ids = value;
RaisePropertyChanged("IDs");
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged(string property)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new
PropertyChangedEventArgs(property));
}
}
}
}
ViewModel
namespace DataBinding_WPF.ViewModel
{
public class ExampleViewModel : INotifyPropertyChanged
{
public ObservableCollection<Example> Examples
{
get;
set;
}
// SelectedItem in the ComboBox
// SelectedItem.Ids will be ItemsSource for the ListBox
private Example _selectedItem;
public Example SelectedItem
{
get => _selectedItem;
set
{
_selectedItem = value;
RaisePropertyChanged(nameof(SelectedItem));
}
}
// SelectedId in ListView
private string _selectedId;
public string SelectedId
{
get => _selectedId;
set
{
_selectedId = value;
RaisePropertyChanged(nameof(SelectedId));
}
}
private string _selectedCheckBox;
public string IsSelected
{
get => _selectedCheckBox;
set
{
_selectedCheckBox = value;
RaisePropertyChanged(nameof(IsSelected));
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged(string property)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new
PropertyChangedEventArgs(property));
}
}
public void LoadExample()
{
ObservableCollection<Example> examples = new ObservableCollection<Example>();
examples.Add(new Example { Name = "Mark", IDs = new string[] { "123", "456" }, IsSelected = false });
examples.Add(new Example { Name = "Sally", IDs = new string[] { "789", "101112" }, IsSelected = false });
Examples = examples;
}
/* BELOW IS A SNIPPET I ADDED FROM AN EXAMPLE I FOUND ONLINE BUT NOT SURE IF IT'S NEEDED */
private ObservableCollection<Example> _bindCheckBox;
public ObservableCollection<Example> BindingCheckBox
{
get => _bindCheckBox;
set
{
_bindCheckBox = value;
RaisePropertyChanged("BindingCheckBox");
}
}
}
}
View
<UserControl x:Class = "DataBinding_WPF.Views.StudentView"
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:local = "clr-namespace:DataBinding_WPF"
mc:Ignorable = "d"
d:DesignHeight = "300" d:DesignWidth = "300">
<Grid>
<StackPanel HorizontalAlignment = "Left" >
<ComboBox HorizontalAlignment="Left"
VerticalAlignment="Top"
Width="120"
ItemsSource="{Binding Path=Examples}"
SelectedItem="{Binding SelectedItem}"
DisplayMemberPath="Name"/>
<ListView x:Name="myListView"
ItemsSource="{Binding SelectedItem.IDs}"
DataContext="{Binding DataContext, ElementName=submit_btn}"
SelectedItem="{Binding SelectedId}"
Height="200" Margin="10,50,0,0"
Width="Auto"
VerticalAlignment="Top"
Background="AliceBlue">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" >
<CheckBox
Name="myCheckBox"
IsChecked="{Binding IsSelected,
RelativeSource={RelativeSource AncestorType=ListViewItem}}"
Margin="5, 0"/>
<TextBlock Text="{Binding}" FontWeight="Bold" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Button HorizontalAlignment="Left" Height="20" Width="100"
Click="Submit" x:Name="submit_btn">Submit</Button>
</StackPanel>
</Grid>
</UserControl>
View.cs
namespace DataBinding_WPF.Views
{
/// <summary>
/// Interaction logic for StudentView.xaml
/// </summary>
public partial class StudentView : UserControl
{
public StudentView()
{
InitializeComponent();
}
private void Submit(object sender, EventArgs e)
{
var selectedItems = ((Button)sender).DataContext;
// process each selected item
// foreach (var selected in ....) { }
}
}
}
The ListView control already exposes a selected items collection as property SelectedItems.
private void Submit(object sender, RoutedEventArgs e)
{
var selectedIds = myListView.SelectedItems.Cast<string>().ToList();
// ...do something with the items.
}
However, I doubt that you want to do this in the code-behind, but rather in the view model. For this purpose, WPF offers the concept of commands.
MVVM - Commands, RelayCommands and EventToCommand
What you need is a relay command or delegate command (the name varies across frameworks). It encapsulates a method that should be executed for e.g. a button click and a method to determine whether the command can be executed as an object that can be bound in the view. Unfortunately, WPF does not provide an implementation out-of-the-box, so you either have to copy an implementation like here or use an MVVM framework that already provides one, e.g. Microsoft MVVM Tookit.
You would expose a property Submit of type ICommand in your ExampleViewModel and initialize it in the constructor with an instance of RelayCommand<T> that delegates to a method to execute.
public class ExampleViewModel : INotifyPropertyChanged
{
public ExampleViewModel()
{
Submit = new RelayCommand<IList>(ExecuteSubmit);
}
public RelayCommand<IList> Submit { get; }
// ...other code.
private void ExecuteSubmit(IList selectedItems)
{
// ...do something with the items.
var selectedIds = selectedItems.Cast<string>().ToList();
return;
}
}
In your view, you would remove the Click event handler and bind the Submit property to the Command property of the Button. You can also bind the SelectedItems property of the ListView to the CommandParameter property, so the selected items are passed to the command on execution.
<Button HorizontalAlignment="Left"
Height="20"
Width="100"
x:Name="submit_btn"
Command="{Binding Submit}"
CommandParameter="{Binding SelectedItems, ElementName=myListView}">Submit</Button>
Additionally, a few remarks about your XAML.
Names of controls in XAML should be Pascal-Case, starting with a capital letter.
You should remove the DataContext binding from ListView completely, as it automatically receives the same data context as the Button anyway.
DataContext="{Binding DataContext, ElementName=submit_btn}"
You can save yourself from exposing and binding the SelectedItem property in your ExampleViewModel, by using Master/Detail pattern for hierarchical data.
<Grid>
<StackPanel HorizontalAlignment = "Left" >
<ComboBox HorizontalAlignment="Left"
VerticalAlignment="Top"
Width="120"
ItemsSource="{Binding Path=Examples}"
IsSynchronizedWithCurrentItem="True"
DisplayMemberPath="Name"/>
<ListView ItemsSource="{Binding Examples/IDs}"
SelectedItem="{Binding SelectedId}"
Height="200" Margin="10,50,0,0"
Width="Auto"
VerticalAlignment="Top"
Background="AliceBlue">
<ListView.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" >
<CheckBox Name="myCheckBox"
IsChecked="{Binding IsSelected, RelativeSource={RelativeSource AncestorType=ListViewItem}}"
Margin="5, 0"/>
<TextBlock Text="{Binding}"
FontWeight="Bold" />
</StackPanel>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Button HorizontalAlignment="Left"
Height="20"
Width="100"
Command="{Binding Submit}"
CommandParameter="{Binding SelectedItems, ElementName=myListView}">Submit</Button>
</StackPanel>
</Grid>
If the view's data context is bound to the view then remove the DataContext from the ListView.
You could remove the item template and instead use a GridView like:
<ListView.View>
<GridView >
<GridViewColumn Header="Selected" >
<GridViewColumn.CellTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsSelected}" Content="{Binding Name}" />
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
Since the ItemSource is an Observable collection, there are several options to monitor changes in the checkboxes:
Add an event handler to the item changed event of the collection and then you can add the Name or the collection index to a local collection. e.g Examples[e.CollectionIndex].Name
Alternatively iterate over the observable collection and select those Examples where Selected = "true"
I am trying to create a multi-select Combobox Custom control, This custom control should expose a dependency property called DropDownDataSource through which the user of the control can decide what day should bound to ComboBox. My code looks like this:
MainPage.Xaml
<Grid>
<local:CustomComboBox x:Name="customcb" DropDownDataSource="{x:Bind DropDownDataSource, Mode=OneWay}" Loaded="CustomControl_Loaded"> </local:CustomComboBox>
</Grid>
MainPage.Xaml.cs
public sealed partial class MainPage : Page, INotifyPropertyChanged
{
private ObservableCollection<Item> _dropDownDataSource;
public ObservableCollection<Item> DropDownDataSource
{
get => _dropDownDataSource;
set
{
_dropDownDataSource = value;
OnPropertyChanged();
}
}
public MainPage()
{
this.InitializeComponent();
}
public event PropertyChangedEventHandler PropertyChanged;
public void OnPropertyChanged([CallerMemberName]string name = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
}
private void CustomControl_Loaded(object sender, RoutedEventArgs e)
{
var Items = new ObservableCollection<Item>(Enumerable.Range(1, 10)
.Select(x => new Item
{
Text = string.Format("Item {0}", x),
IsChecked = x == 40 ? true : false
}));
DropDownDataSource = Items;
}
}
Models
public class Item : BindableBase
{
public string Text { get; set; }
bool _IsChecked = default;
public bool IsChecked { get { return _IsChecked; } set { SetProperty(ref _IsChecked, value); } }
}
public abstract class BindableBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void SetProperty<T>(ref T storage, T value,
[System.Runtime.CompilerServices.CallerMemberName] String propertyName = null)
{
if (!object.Equals(storage, value))
{
storage = value;
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
protected void RaisePropertyChanged([System.Runtime.CompilerServices.CallerMemberName] String propertyName = null)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
CustomUserControl XAML
<Grid x:Name="GrdMainContainer">
<StackPanel Orientation="Vertical" VerticalAlignment="Center" HorizontalAlignment="Center">
<TextBox Width="200" FontSize="24" Text="{Binding Header, Mode=TwoWay}"
IsReadOnly="True" TextWrapping="Wrap" MaxHeight="200" />
<ScrollViewer VerticalScrollBarVisibility="Auto" MaxHeight="200" Width="200" Background="White">
<ItemsControl ItemsSource="{Binding Items}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<CheckBox Content="{Binding Text}"
FontSize="24"
Foreground="Black"
IsChecked="{Binding IsChecked, Mode=TwoWay}"
IsThreeState="False" />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
</StackPanel>
</Grid>
CustomUserControl Cs file
public sealed partial class CustomComboBox : UserControl
{
public CustomComboBox()
{
this.InitializeComponent();
}
public ObservableCollection<Item> DropDownDataSource
{
get { return (ObservableCollection<Item>)GetValue(DropDownDataSourceProperty); }
set { SetValue(DropDownDataSourceProperty, value); }
}
public static readonly DependencyProperty DropDownDataSourceProperty =
DependencyProperty.Register("DropDownDataSource", typeof(ObservableCollection<Item>), typeof(CustomComboBox), new PropertyMetadata("", HasDropDownItemUpdated));
private static void HasDropDownItemUpdated(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (d is CustomComboBox ucrcntrl)
{
var grd = UIElementExtensions.FindControl<Grid>(ucrcntrl, "GrdMainContainer");
grd.DataContext = ucrcntrl.DropDownDataSource as ObservableCollection<Item>;
}
}
}
All looks good to me, but for some reason, Dropdown is coming empty. Instead of the dependency property, If I assign a view model directly to the Control it works fine. But in my condition, it is mandatory that I have properties like DataSource,SelectedIndex, etc on the user control for the end-user to use. Can anyone point out what is going wrong here?
Here, I have attached a copy of my complete code.
I downloaded your sample code, the problem should be in the binding.
<ItemsControl ItemsSource="{Binding Items}">
This way of writing is not recommended. In the ObservableCollection, Items is a protected property and is not suitable as a binding property.
You can try to bind dependency property directly in ItemsControl:
<ItemsControl ItemsSource="{x:Bind DropDownDataSource,Mode=OneWay}">
<ItemsControl.ItemTemplate>
<DataTemplate x:DataType="local:Item">
<CheckBox IsChecked="{x:Bind IsChecked, Mode=TwoWay}"
IsThreeState="False" >
<TextBlock Text="{x:Bind Text}" Foreground="Black" FontSize="24"/>
</CheckBox>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
In addition, you may have noticed that I modified the style of CheckBox and rewritten the content to TextBlock, because in the default style of CheckBox, Foreground is not bound to the internal ContentPresenter.
Thanks.
My client has got the problem with the size of the CheckBox inside a ListBox. I agree, it's small and not so easy to check at times.
I've tried to find a way to make a CheckBox bigger but I've found out that it's complicated (and would require using Blend, which I don't want to use).
What I want to do though is to check the CheckBox when clicking on a whole item.
[ ] some text
In this example - on "some text" or inside the item wherever. Right now I have to click inside the CheckBox to have it checked.
I generate my CheckBoxes dynamically.
My xamls of this control looks like this:
<ListBox Name="restoredDBsListBox" ItemsSource="{Binding ProperlyRestoredDatabases}" Grid.ColumnSpan="2" HorizontalAlignment="Left" Height="170" Margin="34,160,0,0" VerticalAlignment="Top" Width="276" SelectionMode="Extended">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" >
<CheckBox Name="check" IsChecked="{Binding IsChecked, Mode=TwoWay}" Margin="3" VerticalAlignment="Center"/>
<ContentPresenter Content="{Binding Value}" Margin="1"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
and my ViewModel:
/// <summary>
/// Defines the _properlyRestoredDatabases
/// </summary>
private CheckableObservableCollection<string> _properlyRestoredDatabases;
/// <summary>
/// Gets or sets the ProperlyRestoredDatabases
/// </summary>
public CheckableObservableCollection<string> ProperlyRestoredDatabases
{
get { return _properlyRestoredDatabases; }
set
{
_properlyRestoredDatabases = value;
OnPropertyChanged("ProperlyRestoredDatabases");
}
}
CheckableObservableCollection class :
public class CheckableObservableCollection<T> : ObservableCollection<CheckedWrapper<T>>
{
private ListCollectionView _selected;
public CheckableObservableCollection()
{
_selected = new ListCollectionView(this);
_selected.Filter = delegate (object checkObject) {
return ((CheckedWrapper<T>)checkObject).IsChecked;
};
}
public void Add(T item)
{
this.Add(new CheckedWrapper<T>(this) { Value = item });
}
public ICollectionView CheckedItems
{
get { return _selected; }
}
internal void Refresh()
{
_selected.Refresh();
}
}
and CheckedWrapper
public class CheckedWrapper<T> : INotifyPropertyChanged
{
private readonly CheckableObservableCollection<T> _parent;
public CheckedWrapper(CheckableObservableCollection<T> parent)
{
_parent = parent;
}
private T _value;
public T Value
{
get { return _value; }
set
{
_value = value;
OnPropertyChanged("Value");
}
}
private bool _isChecked;
public bool IsChecked
{
get { return _isChecked; }
set
{
_isChecked = value;
CheckChanged();
OnPropertyChanged("IsChecked");
}
}
private void CheckChanged()
{
_parent.Refresh();
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler pceh = PropertyChanged;
if (pceh != null)
{
pceh(this, new PropertyChangedEventArgs(propertyName));
}
}
}
The CheckBox has a Content property so there is no reason to use a separate ContentPresenter. If you also add an ItemContainerStyle that stretches the ListBoxItem container horizontally, you will be able to check and uncheck the CheckBox by clicking anywhere on the row:
<ListBox Name="restoredDBsListBox" ItemsSource="{Binding ProperlyRestoredDatabases}" Grid.ColumnSpan="2" HorizontalAlignment="Left" Height="170" Margin="34,160,0,0" VerticalAlignment="Top" Width="276" SelectionMode="Extended">
<ListBox.ItemContainerStyle>
<Style TargetType="ListBoxItem">
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
</Style>
</ListBox.ItemContainerStyle>
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Name="check" IsChecked="{Binding IsChecked, Mode=TwoWay}"
Content="{Binding Value}"
Margin="3"
VerticalAlignment="Center"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
I have a WPF app and i work there with MVVM.
I have a ViewModel where i hold 2 ObservableCollection private members (Test is a class that i created).
My MainWindow has a TabControl, each tab is connected to another ObservableCollection.
The MVVM works in the first load (If the ObservableCollection item's isChecked is true - the checkBox is checked, and if not - the checkBox is unchecked).
I added a checkBox for SelectAll or UnselectAll.
When clicking on it - I go to the specific ObservableCollection and change all the IsChecked members accordingly to the SelectAll checkBox.
The peoblem is that i don't see it in the GUI (the first load is keeping there, and change just if i click on each checkBox manually)
Should i "refresh" the GUI somehow?
Thanks.
The ViewModel.cs
private ObservableCollection<Test> _basicTests;
private ObservableCollection<Test> _advancedTests;
public ObservableCollection<Test> BasicTests
{
get { return _basicTests; ; }
set
{
_basicTests = value;
OnPropertyChanged("BasicTests");
}
}
public ObservableCollection<Test> AdvancedTests
{
get { return _advancedTests; ; }
set
{
_advancedTests = value;
OnPropertyChanged("AdvancedTests");
}
}
private void OnPropertyChanged(string propertyname)
{
var handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyname));
}
}
}
The MainWindow.xaml:
<TabControl x:Name="tabControl" Margin="0,135,0,0" TabStripPlacement="Left">
<TabItem Header="Basic">
<ListView x:Name="basicTestsList" ItemsSource="{Binding BasicTests}" Background="#FFE5E5E5">
<ListView.ItemTemplate>
<DataTemplate>
<CheckBox x:Name="cbListOfBasicTests"
IsChecked="{Binding IsChecked}"
Content="{Binding Name}"
Margin="0,5,0,0"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</TabItem>
<TabItem Header="Advanced">
<ListView x:Name="advancedTestsList" ItemsSource="{Binding AdvancedTests}" Background="#FFE5E5E5">
<ListView.ItemTemplate>
<DataTemplate>
<CheckBox x:Name="cbListOfAdvancedTests"
IsChecked="{Binding IsChecked}"
Content="{Binding Name}"
Margin="0,5,0,0"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</TabItem>
</TabControl>
Test.cs:
class Test
{
public string Name { get; set; }
public bool IsChecked { get; set; }
}
The ObservableCollection will only raise a OnPropertyChanged event when you add or remove items. If you want the UI to update when you change the IsChecked property, Class Test needs to raise the OnPropertyChanged event when IsChecked is changed:
class Test
{
private bool isChecked;
public bool IsChecked
{
get { return this.isChecked; }
set
{
this.isChecked= value;
this.OnPropertyChanged("IsChecked");
}
}
}
If you don't want to change the model and add OnPropertyChanged, you can do something like this:
_basicTests = new ObservableCollection(_basicTests.ForEach(bt => bt.IsChecked = true));
So I have a simple UDP chat app from a WinForm project, which I wanted to look a little bit better, so I am re-making it in WPF. As I realized I can easily put 2 or more TextBlocks inside of a ListItem, I wanted to display the last message of each chat, like so:
But I have no Idea on how to edit those TextBlocks :( I literary just started with WPF, so I bet I just made a duplicate, but because of that, I don't even know how to search for this issue.
Here is the custom ListBox:
<ListBox x:Name="myList" HorizontalAlignment="Left" Width="264" ScrollViewer.VerticalScrollBarVisibility="Hidden" ScrollViewer.HorizontalScrollBarVisibility="Disabled" BorderThickness="0,1,1,0" MouseLeftButtonUp="myList_MouseLeftButtonUp" Margin="0,25,0,0">
<ListBox.ItemTemplate>
<DataTemplate>
<Border BorderBrush="LightGray" BorderThickness="0,0,0,1" Width="250">
<DockPanel Margin="0,7">
<Ellipse Name="ellipse" Margin="5" DockPanel.Dock="Left" Style="{DynamicResource elstyle}">
</Ellipse>
<TextBlock Text="{Binding Name}" DockPanel.Dock="Top" Margin="0,0,0,7" FontWeight="Bold" MaxWidth="250"></TextBlock>
<TextBlock Text="{Binding ID}" DockPanel.Dock="Top" Visibility="Hidden" FontSize="1.333"></TextBlock>
<TextBlock x:Name="last_message" Text="{Binding LastMessage}" DockPanel.Dock="Bottom" MaxWidth="250"></TextBlock>
</DockPanel>
</Border>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
This is simplified model to show the principal but if you would create view model class that implement INotifyPropertyChanged interface to hold your item data
public class MyItem : INotifyPropertyChanged
{
private string _name;
private string _id;
private string _lastMessage;
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
var handler = this.PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged("Name");
}
}
public string ID
{
get { return _id; }
set
{
_id = value;
OnPropertyChanged("ID");
}
}
public string LastMessage
{
get { return _lastMessage; }
set
{
_lastMessage = value;
OnPropertyChanged("LastMessage");
}
}
}
and then in your window
public partial class MainWindow : Window
{
private readonly ObservableCollection<MyItem> _myItems = new ObservableCollection<MyItem>();
public MainWindow()
{
InitializeComponent();
myList.ItemsSource = _myItems;
_myItems.Add(new MyItem { Name = "name", ID = "id", LastMessage = "last message" });
_myItems[0].LastMessage = "new message";
}
}
and then you don't operate on myList control anymore but on _myItems list and its items. If you add/remove item in the collection it will add/remove item in the UI, if you change property of an item it will update bound property in the UI