Accesing items in ObservableCollection bound to WPF DataGrid

Question

I know this question is similar with Accessing items in ObservableCollection bound to WPF DataGrid

But the answers in this question doesn't helped me.

I've made a Class (DataItem.cs) where my ObservableCollection is. And another class (SelectableViewModel.cs) where the Properties for the Columns are.

public class DataItem : INotifyPropertyChanged
{
    public ObservableCollection<SelectableViewModel> FirmCustomerItems { get; set; } = new ObservableCollection<SelectableViewModel>();
}

public class SelectableViewModel : INotifyPropertyChanged
{
    private string _columnName;

    public string ColumnName
    {
        get { return _columnName; }
        set
        {
            if (_columnName== value) return;
            _columnName= value;
            OnPropertyChanged();
        }
    }
}

If I no want to access to the SelectedItem/Value/Items[0] I will get the following result:

"MyProject.SelectableViewModel".

This is the way how I want to access to the SelectedItem:

DataGrid dataGrid = sender as DataGrid;
switch (dataGrid.Name)
{
    case "FirmCustomerTableDataGrid":
        //var selected = dataGrid.SelectedValue;   // my First try
        //var selected = dataGrid.SelectedItem;    // my Second try
        var selected = dataGrid.SelectedItems[0] // my Third try
        MessageBox.Show(selected.ToString());
        break;
}

I the answers of the linked question at the top of my question is not working because I have a class for the column properties (SelectableViewModel).

But I don't know to solve this problem because I am not much familar with MVVM (rest of code is code-behind)

Answer 1

You need to cast the item to a SelectableViewModel :

var selected = dataGrid.SelectedItems[0] as SelectableViewModel;
if (selected != null)
    MessageBox.Show(selected.ColumnName);