Develop Reference

Binding checkbox ischecked inside listbox(WPF)

I'm trying to bind checkbox ischecked value. but whenever I click multiple checkbox, only last item is get selected.
This is my xaml.
<ListBox x:Name="EntryBox" ItemsSource="{Binding SourceCollection}"
SelectedItem="{Binding SelectedCheckbox}" SelectionMode="Multiple"
Grid.Column="0" Grid.Row="0" >
<ListBox.ItemTemplate>
<DataTemplate>
<ListBoxItem IsSelected="{Binding Selected}">
<StackPanel Orientation="Horizontal">
<CheckBox IsChecked="{Binding Selected}"/>
</StackPanel>
</ListBoxItem>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
My viewmodel
public class MytViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private ObservableCollection<Item> _socketEntryCollection;
public MyViewModel()
{
_socketEntryCollection = new ObservableCollection<Item>();
}
private ListCollectionView _sourceCollection;
public ListCollectionView SourceCollection
{
get { return _sourceCollection; }
set
{
_sourceCollection = value;
NotifyPropertyChanged(nameof(SourceCollection));
}
}
private Item _selectedCheckbox;
public Item SelectedCheckbox
{
get
{
return _selectedCheckbox;
}
set
{
_selectedCheckbox = value;
NotifyPropertyChanged(nameof(SelectedCheckbox));
}
}
public class Item : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private bool _selected;
public Item()
{
_selected = false;
}
public bool Selected
{
get { return _selected; }
set
{
if(_selected != value)
{
_selected = value;
NotifyPropertyChanged(nameof(Selected));
}
}
}
private void NotifyPropertyChanged(string Obj)
{
if (PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(Obj));
}
}
In my code behind,
private MyViewModel _BVM;
public BulkTest()
{
InitializeComponent();
_BVM = new MyViewModel();
}
foreach (MyViewModel.Item i in _BVM.SourceCollection)
{
if (i.Selected)
{
}
}
When I try to retrieve selected items, it only gives me only the last item I checked even though I checked multiple.
I would like to get every item that I checked.
How can I do that?

Can the Visibility of a StackPanel (inside an ItemsControl) be controlled by a button?

I have a property List<Filter> Filters which is the ItemSource of an ItemsControl. What I am trying to accomplish is to show at the beginning only the filters which have the property IsShown = true. Then, when I push the button, to show the rest of the filters. Is it possible to be done using XAML? If no, which approach should I use?
The content of the Filter class is:
public List<string> Options { get; set; } = new List<string>();
public bool IsShown { get; set; }
public string Title { get; set; }
public string ValueSelected { get; set; }
public Filter(List<string> Options, string Title, string ValueSelected, bool IsShown)
{
this.Options = Options;
this.Title = Title;
this.ValueSelected = ValueSelected;
this.IsShown = IsShown;
}
In MainContext I have defined the List and a button:
public ObservableCollection<Filter> Filters { get; set; } = new ObservableCollection<Filter>();
public ICommand DoShowHide
In MainWindow.XAML at this point I have the following:
<ItemsControl ItemsSource="{Binding Filters}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Vertical" Visibility="{Binding Path=IsShown, Converter={StaticResource BoolToVisConverter} }" Name="MyStackPanel">
<TextBlock Text="{Binding Title}"/>
<ComboBox ItemsSource="{Binding Path=Options}"
SelectedValue="{Binding Path=ValueSelected}" />
</StackPanel>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
<Button Content="Show/Hide" Command="{Binding DoShowHide}"/>
with the mentioning that I have defined the converter
<Window.Resources>
<BooleanToVisibilityConverter x:Key="BoolToVisConverter" />
</Window.Resources>
****I have tried to set all the filters' IsShown property to true at the push of the button. No need to mention that it did not work...
private void ShowHide(object obj)
{
MessageBox.Show("message");
foreach(Filter filter in Filters)
{
if(filter.IsShown == false)
{
filter.IsShown = true;
NotifyPropertyChanged("Filters");
}
}
}
Thank you for taking the time to read my question :)

Your Filter class must implement INotifyPropertyChanged. Otherwise property changes inside this class are not propagated to the binding system.
Raising the ProperyChanged event on the Filters property, as you did, is useless.
Note: you can use XOR operation to toggle boolean values (show/hide).
Shortened Filter class:
class Filter : INotifyPropertyChanged
{
private bool isDisplayed
public bool IsDisplayed
{
get => this.isDisplayed;
set
{
if (value != this.isDisplayed)
{
this.isDisplayed = value;
OnPropertyChanged();
}
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
The shortened DataTemplate for the Filter item:
<DataTemplate DataType="{x:Type Filter}">
<StackPanel Visibility="{Binding IsDisplayed, Converter={StaticResource BoolToVisibilityConverter}}">
</StackPanel>
</DataTemplate>
The modified ICommand execution handler:
private void ShowHide(object obj)
{
// Toggle all Filter.IsDisplayed
foreach (Filter filter in Filters)
{
filter.IsDisplayed ^= true;
}
}

you can make it using converter where you return the a visibility object

WPF Record didn't update even with the use of INotifyPropertyChanged

I have a collection of Patients which I set in my ComboBox, whenever I ran and test the form, it seems fine, but whenever I update a record or add another one (from another form), the ComboBox doesn't get updated. I can do a remedy to this by using the code behind and IContent interface but I like to reduce the use of code behind as much as possible. Can you pinpoint to me what markup or code that is lacking?
Here is my Grid Markup (I omitted the RowDefinitions and ColumnDefinitions)
<UserControl.Resources>
<common:ImageSourceConverter x:Key="ToImageSourceConverter" />
<businessLogic:PatientMgr x:Key="PatientsViewModel" />
<ObjectDataProvider x:Key="ItemsSource" ObjectInstance="{StaticResource PatientsViewModel}" />
</UserControl.Resources>
<Grid x:Name="DetailsGrid" DataContext="{StaticResource ItemsSource}">
<Border Grid.Row="1" Grid.RowSpan="8" Grid.Column="0" Grid.ColumnSpan="2" BorderBrush="Turquoise" BorderThickness="2">
<Image x:Name="InsideButtonImage"
VerticalAlignment="Center"
HorizontalAlignment="Center"
StretchDirection="Both" Stretch="Uniform"
Source="{Binding ElementName=FullNameComboBox, Path=SelectedItem.PictureId, Converter={StaticResource ToImageSourceConverter}, UpdateSourceTrigger=PropertyChanged}"
/>
</Border>
<TextBox x:Name="IdTextBox" Text="{Binding ElementName=FullNameComboBox, Path=SelectedItem.Id, UpdateSourceTrigger=PropertyChanged}" Grid.Row="0" Grid.Column="1" Visibility="Collapsed"/>
<ComboBox x:Name="FullNameComboBox" Grid.Row="10" Grid.Column="1" IsEditable="True"
ItemsSource="{Binding Path=ComboBoxItemsCollection, UpdateSourceTrigger=PropertyChanged}"
DisplayMemberPath = "FullName"
SelectedIndex="0"
SelectionChanged="FullNameComboBox_OnSelectionChanged"
/>
<TextBox x:Name="GenderTextBox" Text="{Binding ElementName=FullNameComboBox, Path=SelectedItem.GenderName, UpdateSourceTrigger=PropertyChanged}" Grid.Row="11" Grid.Column="1" IsReadOnly="True" IsReadOnlyCaretVisible="True"/>
</Grid>
Here is my BusinessLogicLayer
public class PatientMgr :INotifyPropertyChanged
{
#region Fields
private readonly PatientDb _db;
private Patient _entity;
private List<Patient> _entityList;
private ObservableCollection<Patient> _comboBoxItemsCollection;
private Patient _selectedItem;
#endregion
#region Properties
public Patient Entity
{
get { return _entity; }
set
{
if (Equals(value, _entity)) return;
_entity = value;
OnPropertyChanged();
}
}
public List<Patient> EntityList
{
get { return _entityList; }
set
{
if (Equals(value, _entityList)) return;
_entityList = value;
OnPropertyChanged();
}
}
public ObservableCollection<Patient> ComboBoxItemsCollection
{
get { return _comboBoxItemsCollection; }
set
{
if (Equals(value, _comboBoxItemsCollection)) return;
_comboBoxItemsCollection = value;
OnPropertyChanged();
}
}
public Patient SelectedItem
{
get { return _selectedItem; }
set
{
if (Equals(value, _selectedItem)) return;
_selectedItem = value;
OnPropertyChanged();
}
}
#endregion
#region Constructor
public PatientMgr()
{
_db = new PatientDb();
Entity = new Patient();
EntityList = new List<Patient>();
Parameters = new Patient();
ComboBoxItemsCollection = new ObservableCollection<Patient>(_db.RetrieveMany(Entity));
SelectedItem = ComboBoxItemsCollection[0];
}
#endregion
public List<Patient> RetrieveMany(Patient parameters)
{
return _db.RetrieveMany(parameters);
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
var handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}

Because ItemsSource used statically, your ComboBox doesn't get notified when it's source changed. Try using an instance of PatientMgr as your UserControl.DataContext like this:
public partial class YourUserControl: UserControl
{
private PatientMgr PatientsViewModel;
public YourUserControl()
{
InitializeComponent();
PatientsViewModel = new PatientMgr();
DataContext = PatientsViewModel;
}
public void AddComboItem(Patient item)
{
PatientsViewModel.ComboBoxItemsCollection.Add(item);
}
public void UpdateComboItem(Patient item)
{
//your update code
}
After removing static bindings, your XAML should looks like this:
<UserControl.Resources>
<common:ImageSourceConverter x:Key="ToImageSourceConverter" />
</UserControl.Resources>
<Grid x:Name="DetailsGrid"
<Border Grid.Row="1" Grid.RowSpan="8" Grid.Column="0" Grid.ColumnSpan="2" BorderBrush="Turquoise" BorderThickness="2">
<Image x:Name="InsideButtonImage" ...
Since ComboBoxItemsCollection is an ObservableCollection, it notifies UI on add/remove automatically, however you have to write proper update functionality in order to force UI to refresh.
EDIT:
To implement an update method by taking advantage of Editable feature of ComboBox you could follow these steps:
Defined an integer property to track the last valid index (index != -1) of combo-box selected item and bind it to FullNameComboBox.SelectedIndex.
Defined a string property that represents the text value of combo-box selected item and bind it to FullNameComboBox.Text (the binding should trigger on LostFocus so the changes only accepted when user finished typing).
Find and remove ComboBoxItemsCollection.OldItem (find it by last valid index) and insert ComboBoxItemsCollection.ModifiedItem when FullNameComboBox.Text changes. Using remove and insert instead of assigning (OldItem = ModifiedItem;) will force UI to update.
In PatientMgr Code:
public int LastValidIndex
{
get { return _lastIndex; }
set
{
if (value == -1) return;
_lastIndex = value;
OnPropertyChanged();
}
}
public string CurrentFullName
{
get
{
return SelectedItem.FullName;
}
set
{
var currentItem = SelectedItem;
ComboBoxItemsCollection.RemoveAt(LastValidIndex);
currentItem.FullName = value;
ComboBoxItemsCollection.Insert(LastValidIndex, currentItem);
SelectedItem = currentItem;
}
}
In UserControl.Xaml :
<ComboBox x:Name="FullNameComboBox" Grid.Row="1" IsEditable="True"
ItemsSource="{Binding Path=ComboBoxItemsCollection,
UpdateSourceTrigger=PropertyChanged}"
SelectedItem="{Binding SelectedItem}"
SelectedIndex="{Binding LastValidIndex}"
IsTextSearchEnabled="False"
Text="{Binding CurrentFullName, UpdateSourceTrigger=LostFocus}"
DisplayMemberPath = "FullName"
/>

I don’t like this:
public ObservableCollection<Patient> ComboBoxItemsCollection
{
get { return _comboBoxItemsCollection; }
set
{
if (Equals(value, _comboBoxItemsCollection)) return;
_comboBoxItemsCollection = value;
OnPropertyChanged();
}
}
Try this:
OnPropertyChanged(“ComboBoxItemsCollection”);
And, are you sure this equals is resolved right?
if (Equals(value, _comboBoxItemsCollection)) return;
Try to debug it …

Your problem has to do with that IsEditable="True" set on the ComboBox. Your bindings work fine for me.
Here is what i've just tried:
Simple Patient model with its FullName property:
public class Patient : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged = delegate { };
private string _FullName;
public string FullName
{
get { return _FullName; }
set
{
_FullName = value;
PropertyChanged(this, new PropertyChangedEventArgs("FullName"));
}
}
}
This is the XAML:
<Window x:Class="PatientsStack.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:PatientsStack"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<local:PatientsMgr x:Key="PatientsViewModel"/>
<ObjectDataProvider x:Key="ItemsSource" ObjectInstance="{StaticResource PatientsViewModel}" />
</Window.Resources>
<Grid DataContext="{StaticResource ItemsSource}">
<StackPanel>
<ComboBox x:Name="FullNameComboBox" IsEditable="True"
ItemsSource="{Binding Path=ComboBoxItemsCollection, UpdateSourceTrigger=PropertyChanged}"
TextSearch.TextPath="FullName"
DisplayMemberPath="FullName"
SelectedItem="{Binding SelectedPatient}"
Text="{Binding SelectedPatient.FullName, Mode=TwoWay}"
VerticalAlignment="Top"
IsTextSearchEnabled="False"
SelectedIndex="0">
</ComboBox>
<Button Content="Change name" Command="{Binding ChangeNameCommand}" CommandParameter="{Binding ElementName=FullNameComboBox, Path=SelectedItem}"/>
<Button Content="Add patient" Command="{Binding AddPatientCommand}" CommandParameter="{Binding ElementName=FullNameComboBox, Path=SelectedItem}"/>
</StackPanel>
</Grid>
This two pieces right here did the job:
SelectedItem="{Binding SelectedFilter}"
Text="{Binding SelectedPatient.FullName, Mode=TwoWay}"
Without the Text binding, the updated worked, but you didn't see it unless you click the drop down.
As you see, i have 2 command to change one existing Patient's FullName or to add a new one. Both work as expected.
Here is the ViewModel for this:
public class PatientsMgr : INotifyPropertyChanged
{
private ObservableCollection<Patient> _ComboBoxItemsCollection;
public ObservableCollection<Patient> ComboBoxItemsCollection
{
get
{
return _ComboBoxItemsCollection;
}
set
{
_ComboBoxItemsCollection = value;
PropertyChanged(this, new PropertyChangedEventArgs("ComboBoxItemsCollection"));
}
}
private Patient _SelectedPatient;
public Patient SelectedPatient
{
get { return _SelectedPatient; }
set
{
_SelectedPatient = value;
PropertyChanged(this, new PropertyChangedEventArgs("SelectedPatient"));
}
}
public ICommand ChangeNameCommand { get; set; }
public ICommand AddPatientCommand { get; set; }
public event PropertyChangedEventHandler PropertyChanged = delegate { };
public PatientsMgr()
{
ComboBoxItemsCollection = new ObservableCollection<Patient>();
ComboBoxItemsCollection.Add(new Patient() { FullName = "Patient1" });
ComboBoxItemsCollection.Add(new Patient() { FullName = "Patient2" });
ComboBoxItemsCollection.Add(new Patient() { FullName = "Patient3" });
ChangeNameCommand = new RelayCommand<Patient>(ChangePatientName);
AddPatientCommand = new RelayCommand<Patient>(AddPatient);
}
public void ChangePatientName(Patient patient)
{
patient.FullName = "changed at request";
}
public void AddPatient(Patient p)
{
ComboBoxItemsCollection.Add(new Patient() { FullName = "patient added" });
}
}
I am posting my RelayCommand too, but i am sure you have it defined for your actions:
public class RelayCommand<T> : ICommand
{
public Action<T> _TargetExecuteMethod;
public Func<T, bool> _TargetCanExecuteMethod;
public RelayCommand(Action<T> executeMethod)
{
_TargetExecuteMethod = executeMethod;
}
public bool CanExecute(object parameter)
{
if (_TargetExecuteMethod != null)
return true;
return false;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
T tParam = (T)parameter;
if (_TargetExecuteMethod != null)
_TargetExecuteMethod(tParam);
}
}

C# ListBox Update Binding Text

I have a ListBox on WP8.1 and want to Bind some items in there. That works all fine, but changing a value on the ItemSource doesn't change anything in the ListBox
<ListBox x:Name="myListBox" Width="Auto" HorizontalAlignment="Stretch" Background="{x:Null}" Foreground="{x:Null}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel x:Name="PanelTap" Tapped="PanelTap_Tapped">
<Border x:Name="BorderCollapsed">
<StackPanel Margin="105,0,0,0">
<TextBlock Text="{Binding myItem.location, Mode=TwoWay}" />
</StackPanel>
</Border>
</ListBox.ItemTemplate>
</ListBox>
I bind the items via
ObservableCollection<LBItemStruct> AllMyItems = new ObservableCollection<LBItemStruct>();
with
public sealed class LBItemStruct
{
public bool ext { get; set; }
public Container myItem { get; set; }
}
public sealed class Container
{
public string location{ get; set; }
...
}
and when I now want to change the TextBlock Text, nothing happens
private void PanelTap_Tapped(object sender, TappedRoutedEventArgs e)
{
int sel = myListBox.SelectedIndex;
if (sel >= 0)
{
myListBox[sel].myItem.location = "sonst wo";
}
}
The PanelTap_Tapped gets triggered, when I tap the Panel (checked via Debug), but the TextBlock Text does not change

If you want the view to update when a property changes, then you need to have the source object implement INotifyPropertyChaned, and raise the PropertyChanged event:
public sealed class Container : INotifyPropertyChanged
{
public string location
{
get { return _location; }
set { _location = value; RaisePropertyChanged("location"); }
}
private string _location;
...
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged(string propName)
{
var handler = PropertyChanged;
if (handler != null)
handler(new PropertyChangedEventArgs(this, propName));
}
}

wpf checkbox list not updating

I have the following ui items - one checkbox list and one checkbox with toggle all checkboxes in that list -
<DockPanel>
<CheckBox
Name="SelectCheckboxes"
Command="{Binding ToggleCheckBoxes}"
Content="Whatever"/>
</DockPanel>
<DockPanel>
<ListBox Name="MyListBox"
ItemsSource="{Binding Path=MyProperty, Mode=TwoWay}">
<ListBox.ItemTemplate>
<DataTemplate>
<CheckBox Name="MyCheckBox"
Content="{Binding myvalue}"
Tag="{Binding mycode}"
IsChecked="{Binding Path=isChecked, Mode=TwoWay}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</DockPanel>
And here is the MyProperty property -
public ObservableCollection<SomeEntity> MyProperty
{
get { return _someEntities; }
set
{
if (value == _someEntities)
return;
_someEntities = value;
base.OnPropertyChanged("MyProperty");
}
}
And here is a command ToggleCheckBoxes -
public ICommand ToggleCheckBoxes
{
get
{
if (_toggleCheckBoxesCommand == null)
{
_toggleCheckBoxesCommand = new RelayCommand(
param => this.toggleCheckBoxes()
);
}
return _toggleCheckBoxesCommand;
}
}
void toggleCheckBoxes()
{
foreach (var i in MyProperty)
{
if (i.isChecked)
i.isChecked = false;
else
i.isChecked = true;
}
}
When I click on the checkbox to toggle the checkboxes, I can look at the property in the code and see that the isChecked property is changed, but the ListBox does not update to reflect that all items are checked/unchecked.
Does anyone see anything that I am missing that might cause the ListBox not to update?
Thnaks for any thoughts.

Make sure that your isChecked member is actually a property and that SomeEntity implements INotifyPropertyChanged. Something like:
public class SomeEntity : INotifyPropertyChanged {
private bool _isChecked;
public bool isChecked
{
get { return _isChecked; }
set
{
if (value == _isChecked)
return;
_isChecked= value;
this.NotifyPropertyChanged("isChecked");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}