DataGrids and data bindings

Question

I'm using C# and XAML to create a dialog box that displays information from a database. The window, more or less, functions the way it should. When it's initialized the database data populate the DataGrid appropriately.

As you can see, there is also a ComboBox that is meant to filter the contents of the DataGrid. It kind of does this. When I select the desired item from the ComboBox, it filters my database, and creates a List<> of the selected object types with all of their data. The problem that I'm having is that can't figure out a way to fill a temporary table with the data from the List<> to populate the DataGrid. What end's up happening is this:

There are the correct number of rows for the elements in the database, and when I run it with a break, and all the correct data is in the List<>; but the data isn't being displayed in the rows.

I can't create a new table in the database for the results because then the data bindings for the DataGrid won't work; I've tried repopulating the table with the information from the List<> via helper classes... Can't figure this out.

Any ideas and/or help would be stellar.

Here is about as much of the code as I can post: XML Data Bindings (the Binding Path is in accordance to columns in the database):

<DataGridTextColumn Header="Size" Binding="{Binding Path=ItemSize }"/>
<DataGridTextColumn Header="Elbow" Binding="{Binding Path=Ell}"/>
<DataGridTextColumn Header="Tee" Binding="{Binding Path=Tee}"/>
<DataGridTextColumn Header="Long-Turn Elbow" Binding="{Binding Path=LngEl}"/>
<DataGridTextColumn Header="Check Valve" Binding="{Binding Path=Chk}"/>
<DataGridTextColumn Header="Butterfly Valve" Binding="{Binding Path=Bfy}"/>
<DataGridTextColumn Header="Gate Valve" Binding="{Binding Path=Gate}"/>
<DataGridTextColumn Header="Alarm Valve" Binding="{Binding Path=Alm}"/>
<DataGridTextColumn Header="Dry Pipe Valve" Binding="{Binding Path=DPV}"/>
<DataGridTextColumn Header="45⁰ Elbow" Binding="{Binding Path=45Ell}"/>
<DataGridTextColumn Header="Tee Run" Binding="{Binding Path=Teerun}"/>
<DataGridTextColumn Header="Coupling" Binding="{Binding Path=Coup}"/>
<DataGridTextColumn Header="Swing Check" Binding="{Binding Path=Swg}"/>

C#:

var newTable = new CEqlTable();

var results = from myRow in vTable.AsEnumerable()
              where myRow.SubCategoryID == GetPipeNumber()
              select myRow;

foreach (DataRow dr in results)
{
     var nextEntry = new CEqlTableRec(
         false, (int)dr[0], (int)dr[1], (double)dr[2], (double)dr[3],
         (double)dr[4], (double)dr[5], (double)dr[6], (double)dr[7],
         (double)dr[8], (double)dr[9], (double)dr[10], (double)dr[11],
         (double)dr[12], (double)dr[13], (double)dr[14], (double)dr[15],
         Convert.ToByte(dr[18]));

    newTable.Add(nextEntry);
}

dgPipeDetail.ItemsSource = newTable;

Answer 1

So never really got enough information to diagnose the issue but below I posted a very simple example of binding to a collection in the code behind. I also put a button on the main window. When the button is clicked I clear the previous data and fill the datagrid with new data. Compare what I have below with what you have. See if it gives you any ideas.

MainWindow.xaml

<Window x:Class="DataGridTest.MainWindow"
        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"
        mc:Ignorable="d"
        Title="MainWindow" 
        Height="350" 
        Width="525"
        DataContext="{Binding RelativeSource={RelativeSource Self}}">
<Grid>
    <DataGrid ItemsSource="{Binding Classes}"
              CanUserAddRows="False"
              AutoGenerateColumns="False"
              Margin="0,0,220,0.5">
        <DataGrid.Columns>
           <DataGridTextColumn Header="FIRST" Binding="{Binding First}"/>
           <DataGridTextColumn Header="SECOND" Binding="{Binding Second}"/>
           <DataGridTextColumn Header="THIRD" Binding="{Binding Third}"/>
           <DataGridTextColumn Header="FOURTH" Binding="{Binding Fourth}"/>
        </DataGrid.Columns>
    </DataGrid>
    <Button Content="Swap" 
            HorizontalAlignment="Left" 
            Margin="400,70,0,0" 
            VerticalAlignment="Top" 
            Width="75"
            Command="{Binding SwapCommand}"/>
</Grid>

MainWindow.xaml.cs

namespace DataGridTest
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            SwapCommand = new RelayCommand(OnExecuteSwap);

            InitializeComponent();

            for(int i = 0; i < 10; i++)
            {
                Classes.Add(
                    new MyClass
                    {
                        First = 10,
                        Second = 20,
                        Third = 30,
                        Fourth = 40
                    });
            }
        }

        private void OnExecuteSwap()
        {
            Classes.Clear();

            for(int i = 0; i < 10; i++)
            {
                Classes.Add(
                    new MyClass
                    {
                        First = 50,
                        Second = 60,
                        Third = 70,
                        Fourth = 80
                    } );
            }
        }

        public ICommand SwapCommand { get; }

        public ObservableCollection<MyClass> Classes { get; } =
            new ObservableCollection<MyClass>();
    }
}

MyClass POCO

namespace DataGridTest
{
    public class MyClass
    {
        public int First { get; set; }
        public int Second { get; set; }
        public int Third { get; set; }
        public int Fourth { get; set; }
    }
}