c# WPF Listbox databinding and getting the row's data item from a click event.

Question

I have a WPF Listbox where the ItemTemplate is made up of a TextBlock and 2 custom hyperlink controls. When a user clicks on one of the hyperlink controls they fire a click event. In this even I need to get data item bound to that listbox row, but I dont know how to reference it. Below is the ListBox xaml and the c# used to set the ItemsSource property.

and the ItemsSource:

List list = new List();
for (int i = 0; i < array.GetUpperBound(0) + 1; i++)
{
    list.Add(new WcRecentView_lst_Binding((object[])array[i]));
}
LbxRecentViews.ItemsSource = list;

and the click event.

        private void BtnTable_Click(object sender, RoutedEventArgs e)
        {

        }

Thank you.

Accepted Answer

HI,
with MVVM pattern you are very flexible. In small applications you can use one ViewModel for MainWindow with UserControls like in following demo. In large applications you can use main ViewModel and ViewModels for UserControls or second Windows.

XAML MainWindow:

Classes:

using System;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Runtime.CompilerServices;  
using System.Windows;  
using System.Windows.Controls;  
using System.Windows.Data;  
using System.Windows.Input;  
  
namespace WpfApp029  
{  
  public class ViewModel : INotifyPropertyChanged  
  {  
    private string _status;  
    public string Status { get => this._status; set { this._status = value; OnPropertyChanged(); } }  
  
    private CollectionViewSource cvs = new CollectionViewSource();  
  
    public ICollectionView View { get => cvs.View; }  
  
    public ICommand BtnTable_Click  
    {  
      get => new RelayCommand((state) => Status = $"BtnTable_Click: {((WcRecentView_lst_Binding)state).AppName}");  
    }  
  
    public ICommand BtnStoredProcedure_Click  
    {  
      get => new RelayCommand((state) => Status = $"BtnStoredProcedure_Click: {((WcRecentView_lst_Binding)state).AppName}");  
    }  
  
    public ICommand Cmd { get => new RelayCommand(CmdExec); }  
  
    private void CmdExec(object state)  
    {  
      switch (state.ToString())  
      {  
        case "From MainWindow":  
          Status = "Click from MainWindow";  
          break;  
        case "From UserControl":  
          Status = "Click from UserControl";  
          break;  
        case "Load From UserControl":  
          LoadData();  
          break;  
        default:  
          break;  
      }  
    }  
  
    private void LoadData()  
    {  
      List list = new List();  
      for (int i = 0; i < 100; i++) list.Add(new WcRecentView_lst_Binding() { AppName = $"App {i}" });  
      cvs.Source = list;  
      OnPropertyChanged(nameof(View));  
    }  
  
    public event PropertyChangedEventHandler PropertyChanged;  
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));  
  }  
  
  public class WcRecentView_lst_Binding  
  {  
    public string AppName { get; set; }  
  }  
  
  public class vHyperlinkButton : Button { }  
  public class RelayCommand : ICommand  
  {  
    private readonly Predicate

Answer

Hi,
you can use MVVM pattern, ICommand-Relay class and bind CommandParamter to data object. Try following demo:

XAML:

And classes:

using System;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Windows;  
using System.Windows.Controls;  
using System.Windows.Data;  
using System.Windows.Input;  
  
namespace WpfApp029  
{  
  public class ViewModel   
  {  
    public ViewModel() => LoadData();  
  
    private CollectionViewSource cvs = new CollectionViewSource();  
  
    public ICollectionView View { get => cvs.View; }  
  
    public ICommand BtnTable_Click { get => new RelayCommand((state) =>   
      MessageBox.Show($"BtnTable_Click: {((WcRecentView_lst_Binding)state).AppName}")); }  
  
    public ICommand BtnStoredProcedure_Click { get => new RelayCommand((state) =>   
      MessageBox.Show($"BtnStoredProcedure_Click: {((WcRecentView_lst_Binding)state).AppName}")); }  
  
    private void LoadData()  
    {  
      List list = new List();  
      for (int i = 0; i < 100; i++) list.Add(new WcRecentView_lst_Binding() { AppName = $"App {i}" });  
      cvs.Source = list;  
    }  
  }  
  
  public class WcRecentView_lst_Binding  
  {  
    public string AppName { get; set; }  
  }  
  
  public class vHyperlinkButton : Button { }  
  public class RelayCommand : ICommand  
  {  
    private readonly Predicate

Answer

Thank you Peter. I need to pass the data in from an outside source based on other events and context. So for example, I would need to make LoadData() public like this:

public void LoadData(List list)

And call this method from outside the ViewModel class - such as from various button click events in Window029 for example, but I don't know how to get access to ViewModel from c# in Window029.

Thank again.

Answer

Hi,
you can include in XAML Button binded to additional ICommand property in ViewModel:

XAML:

Classes:

using System;  
using System.Collections.Generic;  
using System.ComponentModel;  
using System.Runtime.CompilerServices;  
using System.Windows;  
using System.Windows.Controls;  
using System.Windows.Data;  
  
namespace WpfApp029  
{  
  public class ViewModel : INotifyPropertyChanged  
  {  
    private CollectionViewSource cvs = new CollectionViewSource();  
  
    public ICollectionView View { get => cvs.View; }  
  
    public ICommand BtnTable_Click { get => new RelayCommand((state) =>   
      MessageBox.Show($"BtnTable_Click: {((WcRecentView_lst_Binding)state).AppName}")); }  
  
    public ICommand BtnStoredProcedure_Click { get => new RelayCommand((state) =>   
      MessageBox.Show($"BtnStoredProcedure_Click: {((WcRecentView_lst_Binding)state).AppName}")); }  
  
    public ICommand Cmd { get => new RelayCommand(LoadData); }  
  
    private void LoadData(object state)  
    {  
      List list = new List();  
      for (int i = 0; i < 100; i++) list.Add(new WcRecentView_lst_Binding() { AppName = $"App {i}" });  
      cvs.Source = list;  
      OnPropertyChanged(nameof(View));  
    }  
  
    public event PropertyChangedEventHandler PropertyChanged;  
    private void OnPropertyChanged([CallerMemberName] string propName = "") => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));  
  }  
  
  public class WcRecentView_lst_Binding  
  {  
    public string AppName { get; set; }  
  }  
  
  public class vHyperlinkButton : Button { }  
  public class RelayCommand : ICommand  
  {  
    private readonly Predicate

Answer

Thanks for all the samples Peter. The button is calling the command "Command="{Binding Cmd}"", but I need to pass in actual data from outside sources. it could be from a button click event, but could also be from events bubbling up from nested user controls below, or from web service callbacks, etc. I need the flexibility to just pass in a chunk of data and populate the Listbox.

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c# WPF Listbox databinding and getting the row's data item from a click event.

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