Adding data to datagrid in User Control

Question

I made two windows one with user control and i stuck with datagrid. I want to add data in MainWindow and show it in UserControl(Window2) but it's not working, when i change usercontrol to simple window it's fine and works. How can I rewrite It? Im newbie and just learning c# and wpf :)

MainWindow.xaml

public partial class MainWindow : Window
{
    GridControl ngridControl = new GridControl();
    GridWindow ngridWindow = new GridWindow();

    public MainWindow()
    {
        InitializeComponent();
        ngridWindow.Show();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        Information item = new Information();
        item.id = name_box.ToString();
        item.name = number_box.ToString();
        ngridControl.informationList.Add(item);
    }
}

GridControl.xaml

public partial class GridControl : UserControl
{
    public ObservableCollection<Information> informationList = new ObservableCollection<Information>();

    public GridControl()
    {
        InitializeComponent();
        dataGrid.ItemsSource = informationList;
    }
}

}

Information.class

public class Information
{
    public string name { get; set; }
    public string id { get; set; }
}

GridWindow.xaml

<Window x:Class="WpfApp5.GridWindow"
    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:WpfApp5"
    mc:Ignorable="d"
    Title="GridWindow" Height="450" Width="800">
<Grid>
    <local:GridControl> </local:GridControl>
</Grid>

Answer 1

you have two instances of GridControl.

in GridWindow it is <local:GridControl> </local:GridControl> which is displayed without data,

and MainWindow has GridControl ngridControl = new GridControl(); instance which contains data but not displayed anywhere.

what can be done?

the best solution is to change app architecture to MVVM and create view models for your windows. ObservableCollection<Information> informationList will become a property of GridWindowViewModel. GridControl will have a DependencyProperty for binding informationList , instead of common property. MainWindowViewModel will be able to create GridWindowviewModel, use it as a DataContext for GriwWindow and add items to informationList .

the local fix is to work with one GridControl instance in both windows. GridWindow should allow to add item to GridControl.

<Window x:Class="WpfApp5.GridWindow"
    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:WpfApp5"
    mc:Ignorable="d"
    Title="GridWindow" Height="450" Width="800">
    <Grid>
        <local:GridControl> </local:GridControl>
    </Grid>
</Window>

public partial class GridWindow : Window
{
    public GridWindow()
    {
        InitializeComponent();
    }

    public void AddInformation(Information item)
    {
        ngridControl.AddInformation(item);
    }
}

public partial class MainWindow : Window
{
    GridWindow ngridWindow = new GridWindow();

    public MainWindow()
    {
        InitializeComponent();
        ngridWindow.Show();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        Information item = new Information();
        item.id = name_box.ToString();
        item.name = number_box.ToString();
        ngridWindow.AddInformation(item);
    }
}

Answer 2

Give the <GridControl> element in GridWindow.xaml an x:Name :

<local:GridControl x:Name="theControl"> </local:GridControl>

...and add the item to this one's informationList :

public partial class MainWindow : Window
{
    GridWindow ngridWindow = new GridWindow();

    public MainWindow()
    {
        InitializeComponent();
        ngridWindow.Show();
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        Information item = new Information();
        item.id = name_box.ToString();
        item.name = number_box.ToString();
        ngridWindow.theControl.informationList.Add(item);
    }
}