WPF: What's the proper way to do nested Binding - c#

I have 3 models: Machine, Part, and Component. On my ui, I have bound one listbox to a list of Machines and a second listbox to the selected Machine's list of Parts. Now when the user selects a part, I would like to bind a datagrid to the selected part's list of components. I tried setting the datagrid's itemssource to:
ItemsSource="{Binding ElementName=PartSelectList, Path=SelectedItem.Components}"
I also tried setting its datacontext and itemssource
DataContext={Binding ElementName=PartSelectList, Path=SelectedItem}
ItemsSource={Binding Components}
However the datagrid does not automatically update if changes are made to the part's list of components via methods such as
part.Bags.Add(new Component(..));
Anyone have suggestions on how I should approach this?
Update: I have a class MachineCollection which implements INotifyPropertyChanged. In my xaml.cs code I create my MachineCollection object and bind the MainGrid to it's Machines property:
Page1.xaml.cs:
private MachineCollection machines
public Page1()
{
machineCollection = new MachineCollection();
MainGrid.DataContext = machineCollection.Machines
actionThread = new Thread(InitLists);
actionThread.Start();
}
public void InitLists()
{
machineCollection.Machines.AddRange(dbCon.GetAllMachines());
}
Classes:
public class MachineCollection : INotifyPropertyChanged
{
public List<Machine> Machines
{
get { return machines; }
set { machines = value; NotifyPropertyChanged("Machines"); }
}
}
public class Machine : INotifyPropertyChanged
{
public List<Part> Parts
{
get { return parts; }
set { parts = value; NotifyPropertyChanged("Parts");
}
}
public class Part : INotifyPropertyChanged
{
public List<Component> Components
{
get { return components; }
set { components = value; NotifyPropertyChanged("Components");
}
}
public class Component : INotifyPropertyChanged
{
public int Length
{
get { return length; }
set { length = value; NotifyPropertyChanged("Length");
}
}
XAML:
<Page>
<Grid Name="MainGrid">
<ListBox x:Name="MachineSelectList" HorizontalAlignment="Left" VerticalAlignment="Bottom"
Height="114" Width="231"
Foreground="White" Background="#FF7A7A7A" FontSize="16" BorderBrush="#FFC13131"
ItemsSource="{Binding}" IsSynchronizedWithCurrentItem="True">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Width="200">
<TextBlock Text="{Binding SerialNumber}" TextAlignment="Left" HorizontalAlignment="Left" VerticalAlignment="Center"/>
<Button Name="DeleteMachine" Tag="{Binding SerialNumber}" HorizontalAlignment="Right" VerticalAlignment="Center" Height="20"
Background="{x:Null}" BorderBrush="{x:Null}" Foreground="{x:Null}" Focusable="False" Click="Btn_Click" >
<Image Source="..\Resources\Images\delete.png" Stretch="Uniform"/>
</Button>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
<ListBox Name="PartSelectList" HorizontalAlignment="Left" VerticalAlignment="Bottom"
Height="164" Width="231"
Background="#FF7A7A7A" Foreground="White" FontSize="16" BorderBrush="#FFC13131"
ItemsSource="{Binding Path=Parts}" IsSynchronizedWithCurrentItem="True">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Width="200">
<TextBlock Text="{Binding PartNumber}" TextAlignment="Left" HorizontalAlignment="Left" VerticalAlignment="Center"/>
<Button Name="DeletePart" Tag="{Binding PartNumber}" HorizontalAlignment="Right" VerticalAlignment="Center" Height="20"
Background="{x:Null}" BorderBrush="{x:Null}" Foreground="{x:Null}" Focusable="False" Click="Btn_Click" >
<Image Source="..\Resources\Images\delete.png" Stretch="Uniform"/>
</Button>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
</Page>

One way to solve this is using ObservableCollection, which is made for situations like this.
public ObservableCollection<Part> Parts
{
get { return parts; }
set { parts = value; NotifyPropertyChanged("Parts");
}
Or you could implement the interface INotifyCollectionChanged manually
The problem is, basically, that the binding system does not know when you call Add. If you were reassigning the Parts property each time, then the system would just redraw everything, so it would reflect the changes too, but if ObservableCollection is not a problem, that's the prefered way

Related

How to Create a Filter in WPF using Datagrid and ComboBox

So here I have a MVVM form. the Form contains a Datagrid which is connected to the Databank. I also have a ComboBox which I want to use as a filter option. The Filter option shoud filter by the "AnlV nr" so when the user selects "01" from the ComboBox the datagrid should refresh and show only that "AnlV nr" that have "01" Below I will share you the code and you can see that i've gotten as far as showing the "AnlV" values in the ComboBox but I now do not know how to do the rest and make the filter work. Below is my Viewmodel and the Xaml code.
If anyone can help me with this I would really apreciate it.
Xaml Code:
<Window x:Class="QBondsFrontend.Views.Input.AnlVTexteView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:QBondsFrontend.Views.Input" xmlns:input="clr-namespace:QBondsFrontend.ViewModels.Input" d:DataContext="{d:DesignInstance Type=input:AnlVTexteViewModel}"
mc:Ignorable="d"
Title="AnlVTexteView"
Width="800"
MinHeight="400"
Height="490"
MinWidth="1010"
MaxWidth="1010"
UseLayoutRounding="True">
<Grid Background="#A8A8A8" >
<StackPanel VerticalAlignment="Top" Background="#A8A8A8" Orientation="Horizontal" Height="57">
<Label
Content="AnlV Nr.:" Height="35" FontSize="12"/>
<ComboBox Background="LightGray" Height="20" Width="70" ItemsSource="{Binding lstAnlVTexte}" SelectedItem="{Binding Search}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding AnlVPara}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
<Button Height="18" Width="68" Margin="5, 0"
Content="Filter löschen" FontSize="11" Style="{StaticResource STL_ButtonStandard}"
x:Name="filterlöschen"
Command="{Binding icdFilterDelete}"/>
</StackPanel>
<StackPanel Background="LightGray" VerticalAlignment="Top" Height="177" Margin="0,57,0,0">
<DataGrid x:Name="datagridXAML"
Height="177"
ItemsSource="{Binding lstAnlVTexte, Mode=TwoWay}"
Style="{StaticResource STL_DataGridReporting}"
CellStyle="{StaticResource STL_DataGridCellReporting}"
ColumnHeaderStyle="{StaticResource STL_DataGridColumnHeaderReporting}"
AlternatingRowBackground="#A8A8A8"
CanUserResizeColumns="False"
>
<DataGrid.Columns>
<DataGridTextColumn Header="AnlV-Nr"
Binding="{Binding AnlVPara}"
Width="60"/>
<DataGridTextColumn Header="gültig ab"
Binding="{Binding TextGueltigAb}"
Width="68"/>
<DataGridTextColumn Header="Text"
Binding="{Binding ParaText}"
Width="750"/>
<DataGridTextColumn Header="Info"
Binding="{Binding Info}"
Width="*"/>
</DataGrid.Columns>
</DataGrid>
</StackPanel>
<StackPanel Background="#A8A8A8" HorizontalAlignment="Center" Margin="10,268,0,141" Width="1010" >
<Label Content="Bearbeitungsbereich" FontWeight="Bold" FontSize="12" Height="33" />
</StackPanel>
<StackPanel>
<StackPanel Orientation="Horizontal" Background="#A8A8A8" HorizontalAlignment="Center"
Width="1010" Margin="0,294,0,0" Height="31">
<Label Height="25" Width="60" Margin="20, 0, 0, 0" Content="AnlV-Nr.:" />
<ComboBox IsEditable="True" Background="gray" Height="22" Width="69" ItemsSource="{Binding AnlVPara}">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding lstAnlVTexte}"/>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
<CheckBox Height="15" Margin="10, 0, 0, 0" />
<Label Height="26" Width="122" Content="Editierwarnungen" />
<StackPanel Height="48" Width="100"/>
</StackPanel>
<StackPanel Height="22" Orientation="Horizontal">
<Label Margin="20, 0, 0, 0" Content="gültig ab:" Height="27" />
<TextBox Background="LightGray" Height="20" Width="100" />
</StackPanel>
<StackPanel Height="50" Orientation="Horizontal">
<Label Content="Text:" Height="27" Width="38" Margin="42,0,0,10" />
<TextBox Background="LightGray" Width="500" Height="43" />
</StackPanel>
<StackPanel Orientation="Horizontal" >
<Label Content="Info:" Height="27" Width="38" Margin="42,0,0,0" />
<TextBox Background="LightGray" Width="500" Height="20" />
<Button x:Name="BTN_speichern" Width="80" Height="18" Margin="20,0,0,0" Content="Speichern"
Style="{StaticResource STL_ButtonStandard}" Command="{Binding icdSpeichern}"/>
</StackPanel>
</StackPanel>
</Grid>
</Window>
ViewModel:
using Newtonsoft.Json;
using QBondsData.DBModels;
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;
using System.Linq;
namespace QBondsFrontend.ViewModels.Input
{
public class AnlVTexteViewModel : BaseViewModel
{
#region data
private string _AnlVPara;
private DateTime _TextGueltigAb;
private string _ParaText;
private string _Info;
private List<AnlVhistText> _lstAnlVTexte;
private string _search;
#endregion
#region constructor
public AnlVTexteViewModel()
{
icdFilterDelete = new RelayCommand<object>(parameter => filterdelete(), parameter => true);
icdSpeichern = new RelayCommand<object>(parameter => speichern(), parameter => true);
GetData();
}
#endregion
#region members
public ICommand icdFilterDelete { get; set; }
public ICommand icdSpeichern { get; set; }
private string Search
{
get { return _search; }
set
{
_search = value;
OnPropertyChanged("Search");
}
}
public string AnlVPara
{
get
{
return _AnlVPara;
}
set
{
_AnlVPara = value;
OnPropertyChanged("AnlVPara");
}
}
public DateTime TextGueltigAb
{
get
{
return _TextGueltigAb;
}
set
{
_TextGueltigAb = value;
OnPropertyChanged("TextGueltigAb");
}
}
public string ParaText
{
get
{
return _ParaText;
}
set
{
_ParaText = value;
OnPropertyChanged("ParaText");
}
}
public string Info
{
get
{
return _Info;
}
set
{
_Info = value;
OnPropertyChanged("Info");
}
}
public List<AnlVhistText> lstAnlVTexte
{
get { return _lstAnlVTexte; }
set
{
_lstAnlVTexte = value;
OnPropertyChanged("lstAnlVTexte");
}
}
#endregion
#region methods
private void filterdelete()
{
}
private void speichern()
{
}
private async Task GetData()
{
HttpResponseMessage Response = await Globals.SendRequest("AnlVTexte/GetAnlVTexte"
, "GET");
if (Response.IsSuccessStatusCode)
{
lstAnlVTexte = JsonConvert.DeserializeObject<List<AnlVhistText>>
(await Response.Content.ReadAsStringAsync());
}
else
{
lstAnlVTexte = new List<AnlVhistText>();
Application.Current.Dispatcher.Invoke((Action)delegate
{
Globals.CloseReportByHash(this.GetHashCode()
, "Fehler! (HTTP Status " + Response.StatusCode + ")." +
"Kontaktieren Sie den Support.");
});
}
}
#endregion
}
}
When you change the type of lstAnlVTexte to ICollectionView you get two events CurrentChanged and CurrentChanging which you can handle in your viewmodel. From the ICollectionView you can get the CurrentItem.
Like this:
private List<AnlVhistText> _anlVTexte = new List<AnlVhistText>();
public AnlVTexteViewModel()
{
[...]
lstAnlVTexte = new CollectionView(_anlVTexte);
lstAnlVTexte.CurrentChanged += SelectionChanged; // raised after the current item has been changed.
lstAnlVTexte.CurrentChanging += SelectionChanging; // raise before changing the current item. Event handler can cancel this event.
}
private void SelectionChanged(object sender, EventArgs e)
{
var selectedItem = lstAnlVTexte.CurrentItem;
}
private void SelectionChanging(object sender, CurrentChangingEventArgs e)
{
}
private ICollectionView _lstAnlVTexte;
public ICollectionView lstAnlVTexte
{
get { return _lstAnlVTexte; }
set
{
_lstAnlVTexte = value;
OnPropertyChanged("lstAnlVTexte");
}
}
Here's a sample using the community toolkit mvvm and linq.
If you're not familiar, the toolkit does code generation.
This is a simple scenario to illustrate the approach.
Mainwindowviewmodel.
public partial class MainWindowViewModel : ObservableObject
{
[ObservableProperty]
private int selectedFilterInt = -1;
partial void OnSelectedFilterIntChanged(int newValue)
{
FilteredList = new ObservableCollection<MyItem>(FullList.Where(x=>x.Category == selectedFilterInt).ToList());
}
public List<int> FilterOptions { get; set; } = new List<int> {1,2,3};
private List<MyItem> FullList= new List<MyItem>
{
new MyItem{ Category = 1},
new MyItem{ Category = 1},
new MyItem { Category = 1 },
new MyItem { Category = 2 },
new MyItem { Category = 2 },
new MyItem { Category = 3 }
};
[ObservableProperty]
private ObservableCollection<MyItem> filteredList = new ObservableCollection<MyItem>();
public MainWindowViewModel()
{
FilteredList = new ObservableCollection<MyItem>(FullList);
}
}
There's a full list of all the items.
But a filtered list is going to be bound to the itemssource of my listbox ( equivalent to your datagrid ).
Due to the code generated, when selectedFilterInt changes, OnSelectedFilterIntChanged will be called. It's got a handler listening for property changed of SelectedFilterInt if you dug into the generated code.
That method uses a linq where to filter the full list into filtered list.
Setting that filtered list property raises property changed and the view re reads the new collection.
MainWindow. ( I did mention this is simplified )
<Window.DataContext>
<local:MainWindowViewModel/>
</Window.DataContext>
<Grid>
<StackPanel>
<ComboBox SelectedItem="{Binding SelectedFilterInt}"
ItemsSource="{Binding FilterOptions}"/>
<ListBox ItemsSource="{Binding FilteredList}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Category}"/>
<TextBlock Text="{Binding Comment}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</Grid>
</Window>
and MyItem
public partial class MyItem : ObservableObject
{
[ObservableProperty]
private int category = 0;
[ObservableProperty]
private string comment = "Some test string";
}
Which is a bit underwhelming visually but works:
In your code you need to get all the data into a collection.
Call that FulList.
You then need another collection which will be the filtered data.
Call this FilteredList.
Bind itemssource to FilteredList
Initially, you presumably want FilteredList to be = FullList
Then when the user selects something in the combobox you need to react to that.
You could bind selecteditem to a property and act in the setter or handle propertychanged like my code does.
However you do it, you get a new integer.
You then use that to filter FullList into a new collection which will replace the bound FilteredList.
You also need to somehow have one entry per AnlV nr whatever that is in your combobox.
AnlV nr isn't going to work as a property name since it's got a space but it is the equivalent to Category in my sample.
You will use that selected value in the linq.
Substitute the name of that property for Category. Substitute the type of whatever your collection is. Maybe that's AnlVhistText. I'm not sure.

Adding buttons to WPF from ObservableCollection using MVVM pattern

I'm trying to add buttons to UserControl. I have to follow MVVM pattern. I have created a class, DeviceButton, with different set/gets and a constructor. In a viewmodel, used as datacontext, is the ObservableCollection and a get-method for the collection. I have bound the collection to a ItemsControl source and tried to add a template. I guess I'm missing something 'cause the buttons won't load.
The UserControl is added into a tab (using dragablz) which as well is a part of a ObservableCollection, also added at run time (this is working just fine). The idea is, that the tab has a list of buttons that has to be created at run time, where the list is fetched from a web service - so the buttons has to be added dynamically/programatically. Overview is just the first tab - a template for each tab (reflecting the fetched items) is being implemented when the buttons work. For now, I'm just adding a test button to the collection, but as stated, this won't show. What am I missing?
I have a Overview.xaml file:
<UserControl // attributes omitted to save spaces... ask if needed>
<StackPanel>
<Border>
<TextBlock FontSize="16" FontWeight="Bold" TextWrapping="WrapWithOverflow"
TextAlignment="Center" HorizontalAlignment="Center"
Foreground="{DynamicResource AccentColorBrush}">
Welcome to Greenhouse App
</TextBlock>
</Border>
<ItemsControl ItemsSource="{Binding DeviceButtons}">
<ItemsControl.ItemTemplate>
<DataTemplate DataType="{x:Type vmodel:DeviceButton}">
<Button Width="50" Height="50" Margin="10 10 0 0" Command="{Binding OpenTab}"
CommandParameter="{Binding DeviceType}" HorizontalAlignment="Left"
VerticalAlignment="Top" Style="{DynamicResource SquareButtonStyle}">
<StackPanel>
<Image Source="{Binding ImageUrl}" />
</StackPanel>
</Button>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
// Manually added test button...
<Button x:Name="windMill" HorizontalAlignment="Left" Margin="10,0,0,0"
VerticalAlignment="Top" Width="50" Height="50"
Command="{Binding OpenTab}" FontFamily="Segoe Ui"
Style="{DynamicResource SquareButtonStyle}">
<StackPanel>
<Image Source="/Greenhouse;component/Icons/Windmill.png" />
</StackPanel>
</Button
</StackPanel>
I'm trying to add an ObservableCollection of type DeviceButton, the _deviceButtons collection (Binded as ItemsSource to the ItemsControl)
The tabList items are working just find, and I can manually add more if needed (these will later be added through the OpenNewTab-command, which should be bound to the buttons)
The DeviceButton file:
public class DeviceButton
{
private readonly string _content;
private readonly string _deviceType;
private readonly string _imageUrl;
public DeviceButton(string content, string deviceType, string imageUrl)
{
_content = content;
_deviceType = deviceType;
_imageUrl = imageUrl;
}
public string Content
{
get { return _content; }
}
public string DeviceType
{
get { return _deviceType; }
}
public string ImageUrl
{
get { return _imageUrl; }
}
}
The collection is located in a viewmodel file, MainWindowViewModel.cs:
public class MainWindowViewModel : ViewModelBase, INotifyPropertyChanged
{
public ICommand OpenTab { get; set; }
private string tabControl { get; set; } = "0";
private IInterTabClient _interTabClient;
private ObservableCollection<TabContent> _tabContents = new ObservableCollection<TabContent>();
private ObservableCollection<DeviceButton> _deviceButtons = new ObservableCollection<DeviceButton>();
public MainWindowViewModel()
{
_interTabClient = new MyInterTabClient();
DeviceButtons.Add(new DeviceButton("Windturbine", "windturbine", "/Greenhouse;component/Icons/Windmill.png"));
TabContents.Add(new TabContent("Overview", new Overview()));
OpenTab = new RelayCommand<object>(OpenNewTab);
}
private void OpenNewTab(object obj)
{
MessageBox.Show("Yo"); // Not yet implemented
RaisePropertyChanged(() => tabControl);
}
public ObservableCollection<TabContent> TabContents
{
get { return _tabContents; }
}
public ObservableCollection<DeviceButton> DeviceButtons
{
get { return _deviceButtons; }
}
public IInterTabClient InterTabClient
{
get { return _interTabClient; }
}
}
The buttons aren't loaded when I start the program (only the "test" button added manually in the WPF).
The UserControl, Overview, is considered a tab in another Controls.Metrowindow, MainWindow.xaml:
<Window.Resources>
<Style TargetType="{x:Type dragablz:TabablzControl}">
<Setter Property="CustomHeaderItemTemplate">
<Setter.Value>
<DataTemplate DataType="{x:Type viewmodel:TabContent}">
<TextBlock Text="{Binding Header}" />
</DataTemplate>
</Setter.Value>
</Setter>
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate DataType="{x:Type viewmodel:TabContent}">
<ContentPresenter Margin="4" Content="{Binding Content}" />
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<dragablz:TabablzControl SelectedIndex="{Binding tabControl}" ItemsSource="{Binding TabContents}" x:Name="InitialTabablzControl" Margin="4 0 4 4">
<dragablz:TabablzControl.InterTabController>
<dragablz:InterTabController InterTabClient="{Binding MyInterTabClient}" />
</dragablz:TabablzControl.InterTabController>
</dragablz:TabablzControl>
I guess it's an issue with the resources/binding in the Overview.xaml, but I've exhausted all suggested solutions I could find.
Issue was in binding
ItemsSource="{Binding Path=DataContext.TabContents,
RelativeSource={RelativeSource AncestorLevel=1,
AncestorType={x:Type Window}, Mode=FindAncestor}}"
I suspect the DataContext is being set to a TabContent object, which does not have a DeviceButtons property
I would suggest using a tool like Snoop to verify your DataContext is what you expect.

Display multiple local database value in listbox

I'm trying to list out data from a local database to a list box for WP8.1
.xaml:
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,17">
<Image Source= "**Fruit Image**" Height="26" Width="50" Margin="12,10,9,0" VerticalAlignment="Top"/>
<TextBlock Text="**Fruit Name**" FontSize="26" Style="{StaticResource BodyTextBlockStyle}"/>
<TextBlock Text="**Fruit Colour**" FontSize="26" Style="{StaticResource BodyTextBlockStyle}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
Getting value from my database
.cs:
public void ListFruit()
{
using (var db = new SQLite.SQLiteConnection(this.DBPath))
{
List<Fruits> retrievedTasks = db.Table<Fruits>().ToList<Fruits>();
}
}
.cs
public class Fruits
{
public string ImgPath { get; set; }
public string FruitName { get; set; }
public string FruitColour{ get; set; }
}
I'm not really sure if the method i'm using is correct, please guide me. Thanks!
You have defined properties in your class, you have filled your List<Fruit> with items.
What you should else do is (if you haven't done it already):
Define your List<Fruit> as ItemsSource of Listbox
public void ListFruit()
{
using (var db = new SQLite.SQLiteConnection(this.DBPath))
{
List<Fruits> retrievedTasks = db.Table<Fruits>().ToList<Fruits>();
myListbox.ItemsSource = retrievedTasks; // or directly
}
}
You may also think of using ObservableCollection instead of List - in this case you need to set ItemsSource only once - for example in constructor of the Page. You may also think of implementing INotifyPropertyChanged so that you can inform View when item changes.
And I'm not sure if you had defined Binding in your xaml (or somewhere else):
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" Margin="0,0,0,17">
<Image Source= "{Binding ImgPath}" Height="26" Width="50" Margin="12,10,9,0" VerticalAlignment="Top"/>
<TextBlock Text="{Binding FruitName}" FontSize="26" Style="{StaticResource BodyTextBlockStyle}"/>
<TextBlock Text="{Binding FruitColour}" FontSize="26" Style="{StaticResource BodyTextBlockStyle}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>

Listbox with UserControl ItemTemplate always shows default values

To start off, I have a listbox that is trying to accept a UserControl as the DataTemplate:
<ListBox VerticalAlignment="Stretch" Name="GeneralMcmView" Grid.Column="0" HorizontalAlignment="Stretch" >
<ListBox.ItemTemplate>
<DataTemplate DataType="local:GeneralMcmMessage">
<local:GeneralMcmMessage />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
With the contents of the usercontrol looking like:
<ContentControl FontFamily="Segoe UI" VerticalAlignment="Stretch" FontSize="10">
<Grid VerticalAlignment="Stretch">
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<StackPanel VerticalAlignment="Stretch" Orientation="Horizontal" Grid.Row="0">
<TextBlock Name="MessageDateTime" Text="{Binding ElementName=_this, Path=TimeStamp, StringFormat=MM/dd/yyyy h:mm:ss.fff tt \'GMT\' (zzz)}" />
<TextBlock Name="MessageTypeLabel" Margin="15,0,5,0" Text="Type:"/>
<TextBlock Name="MessageType" Text="{Binding ElementName=_this, Path=Type}" />
</StackPanel>
<StackPanel VerticalAlignment="Stretch" Orientation="Horizontal" Grid.Row="1">
<TextBlock Name="MessageNameLabel" Margin="0,0,5,0" Text="Message Name:" />
<TextBlock Name="MessageNameValue" Text="{Binding ElementName=_this, Path=MessageName}" TextWrapping="Wrap" />
</StackPanel>
<StackPanel VerticalAlignment="Stretch" Orientation="Vertical" Grid.Row="2">
<TextBlock Name="MessageLabel" Text="Message:"/>
<TextBlock Name="Message" Margin="10,0,0,0" Text="{Binding ElementName=_this, Path=MessageContent}" />
</StackPanel>
</Grid>
</ContentControl>
I then create a couple messages, all with different data (The Listbox's ItemSource is bound to the GeneralMessages ObservableCollection):
GeneralMcmMessage newMsg = new GeneralMcmMessage()
{
MessageId = e.McmMessageViewInfo.Id,
TimeStamp = e.McmMessageViewInfo.MessageDateTime,
Type = e.McmMessageViewInfo.MessageType.ToString(),
MessageName = e.McmMessageViewInfo.MessageName,
MessageContent = e.McmMessageViewInfo.Message.ToString()
};
GeneralMessages.Add( newMsg );
During runtime I interrogate the Items property of the listbox and all the data looks correct, however all I see in the listbox are entries of the GeneralMcmMessage User Control with default data values. Any ideas as to why?
Also, FWIW I am using INotifyPropertyChanged in the usercontrol class:
public partial class GeneralMcmMessage : UserControl, INotifyPropertyChanged
{
private Constants.PiuModule piuModule = Constants.PiuModule.MCM;
private string className = "GeneralMcmMessage";
/// <summary>
/// Event for notifying listeners that a property changed. Part of INotifyPropertyChanged
/// </summary>
public event PropertyChangedEventHandler PropertyChanged;
public int MessageId { get; set; }
private DateTime timeStamp;
public DateTime TimeStamp
{
get
{
return timeStamp;
}
set
{
timeStamp = value;
OnNotifyPropertyChanged( "TimeStamp" );
}
}
You're saying that the DataTemplate to display a GeneralMcmMessage is to instantiate new GeneralMcmMessage.
<DataTemplate DataType="local:GeneralMcmMessage">
<local:GeneralMcmMessage />
</DataTemplate>
I'd recommend instead of making a collection of your UserControl to make a collection of your model object instead, and bind to the properties within that within your UserControl.
Either way though - the object you created in code will be the DataContext for the one you created in XAML so removing the ElementName=_this should bind appropriately. Try this simplified XAML in your UserControl instead.
<StackPanel VerticalAlignment="Stretch" Orientation="Horizontal" Grid.Row="0">
<TextBlock Name="MessageDateTime" Text="{Binding TimeStamp, StringFormat=MM/dd/yyyy h:mm:ss.fff tt \'GMT\' (zzz)}" />
<TextBlock Name="MessageTypeLabel" Margin="15,0,5,0" Text="Type:"/>
<TextBlock Name="MessageType" Text="{Binding Type}" />
</StackPanel>
<StackPanel VerticalAlignment="Stretch" Orientation="Horizontal" Grid.Row="1">
<TextBlock Name="MessageNameLabel" Margin="0,0,5,0" Text="Message Name:" />
<TextBlock Name="MessageNameValue" Text="{Binding MessageName}" TextWrapping="Wrap" />
</StackPanel>
<StackPanel VerticalAlignment="Stretch" Orientation="Vertical" Grid.Row="2">
<TextBlock Name="MessageLabel" Text="Message:"/>
<TextBlock Name="Message" Margin="10,0,0,0" Text="{Binding MessageContent}" />
</StackPanel>
You don’t post all code of GeneralMcmMessage hence I don’t know if you set DataContext in user control for example in constructor of GeneralMcmMessage.
I tried replicate your problem.
User control GeneralMcmMessage code behind
public partial class GeneralMcmMessage : UserControl, INotifyPropertyChanged
{
private int _messageId;
public int MessageId
{
get
{
return _messageId;
}
set
{
_messageId = value;
OnPropertyChanged("MessageId");
}
}
private DateTime _timeStamp;
public DateTime TimeStamp
{
get
{
return _timeStamp;
}
set
{
_timeStamp = value;
OnPropertyChanged("TimeStamp");
}
}
public GeneralMcmMessage()
{
InitializeComponent();
//don’t set data context here
//DataContext = this;
}
}
User control GeneralMcmMessage XAML
<StackPanel>
<TextBlock Margin="5" FontSize="20" Text="{Binding Path=MessageId}"/>
<TextBlock Margin="5" FontSize="20" Text="{Binding Path=TimeStamp}"/>
</StackPanel>
User control GeneralMcmMessage usage
public partial class MainWindow : Window, INotifyPropertyChanged
{
private ObservableCollection<GeneralMcmMessage> _generalMessages;
public MainWindow()
{
InitializeComponent();
DataContext = this;
}
public ObservableCollection<GeneralMcmMessage> GeneralMcmMessages
{
get { return _generalMessages; }
set
{
_generalMessages = value;
OnPropertyChanged("GeneralMcmMessages");
}
}
private void MainWindow_OnLoaded(object sender, RoutedEventArgs e)
{
GeneralMcmMessages = new ObservableCollection<GeneralMcmMessage>();
for (int i = 0; i < 10; i++)
{
var newMsg = new GeneralMcmMessage
{
MessageId = i,
TimeStamp = DateTime.Now,
};
GeneralMcmMessages.Add(newMsg);
}
}
}
User control GeneralMcmMessage usage XAML
<ListBox x:Name="ListBox"
Margin="5"
ItemsSource="{Binding Path=GeneralMcmMessages}">
<ListBox.ItemTemplate>
<DataTemplate DataType="stackoverflow:GeneralMcmMessage">
<stackoverflow:GeneralMcmMessage/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
If this not solve your problem could you please post all GeneralMcmMessage?
If you want I can upload sample project for you.
Thank you

Nested Listbox wont display nested list

<ListBox Height="434" HorizontalAlignment="Left" Margin="6,238,0,0" Name="listBox1" VerticalAlignment="Top" Width="432" DataContext="{Binding}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Name}" Margin="4" Foreground="{StaticResource PhoneAccentBrush}"></TextBlock>
<StackPanel Orientation="Horizontal" Margin="4">
<TextBlock Text="Set" Margin="16" Foreground="{StaticResource PhoneAccentBrush}" />
<TextBlock Text="Weight" Margin="16" Foreground="{StaticResource PhoneAccentBrush}" />
<TextBlock Text="Reps" Margin="10,16,0,16" Foreground="{StaticResource PhoneAccentBrush}" />
</StackPanel>
<ListBox Name="setsAndReps" Height="auto" Width="auto" ItemsSource="{Binding Sets}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBox Text="{Binding SetNumber}"/>
<TextBox Text="{Binding Weight}"/>
<TextBox Text="{Binding Reps}"/>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
The outer listbox's item source is being set to an observable collection of a user defined class called excercise
public class excercise : IComparable, IEquatable<excercise>, INotifyPropertyChanged
{
string name;
int max;
int NUM_SETS;
ObservableCollection<set> sets;
public event PropertyChangedEventHandler PropertyChanged;
public string Name
{
get { return this.name; }
set { this.name = value; }
}
public excercise(string name)
{
this.name = name;
this.NUM_SETS = 0;
this.sets = new ObservableCollection<set>();
}
public ObservableCollection<set> Sets
{
get{return this.sets; }
}
public ObservableCollection<set> getSets()
{
return this.sets;
}
}
The properties in the inner list box are from the set class but none of them are being displayed and I am not sure what the problem is.
your first listbox doesn't have any itemsource set and the datacontext is set to an empty binding (both on line 1 of your code)

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