I don't know how to ask this question but I will try my best. I have ObservableCollection that is bind to GridView and that GridView has a column with combobox and I need while filling the gridview with the data from ObservableCollection to automatically select the item from combobox.

XAML

<DataGrid x:Name="dg" AutoGenerateColumns="False">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="Date"></DataGridTextColumn>
                    <DataGridTextColumn Header="Description"></DataGridTextColumn>
                    <DataGridTemplateColumn Header="Status" Width="100">
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <ComboBox Name="cb" SelectedItem="{Binding Path=Status}" SelectionChanged="cb_SelectionChanged" ItemsSource="{Binding Source={local:EnumBindingSourceExtention {x:Type local:status}}}"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                </DataGrid.Columns>
            </DataGrid>

MainWindow.xaml.cs

    public partial class MainWindow : Window
    {
        public ObservableCollection<Record> TasksList = new ObservableCollection<Record>();
        public string DbDoc;
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = this;
        }

        private void AddRecord(Record task)
        {
            TasksList.Add(task);
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            DbDoc = System.IO.Path.Combine(Directory.GetCurrentDirectory(), "records.xml");
            if (File.Exists(DbDoc))
            {
                using (StreamReader reader = new StreamReader(DbDoc))
                {
                    XmlSerializer serializer = new XmlSerializer(typeof(Records));
                    Records records = (Records)serializer.Deserialize(reader);
                    records.RecordsList.ForEach(a=>TasksList.Add(a));
                    dg.ItemsSource = TasksList;
                }
            }
        }
    }
    [XmlRoot("Records")]
    public class Records
    {
        [XmlElement("Record", typeof(Record))]
        public List<Record> RecordsList { get; set; }
    }
    public class Record
    {
        [XmlElement("Date")]
        public string Date { get; set; }
        [XmlElement("Description")]
        public string Description { get; set; }
        [XmlElement("Status")]
        public string Status { get; set; }

    }
        public class EnumBindingSourceExtention : MarkupExtension
    {
        public Type EnumType { get; private set; }

        public EnumBindingSourceExtention(Type enumType)
        {
            if (enumType == null || !enumType.IsEnum)
            {
                throw new Exception("EnumType is null or not EnumType");
            }
            this.EnumType = enumType;
        }

        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return Enum.GetValues(EnumType);
        }
    }
    public enum status
    {
        New,
        Old
    }

so, I need in window loading while binding the TasksList to the datagrid dg to also get the Status string and select the item from combobox.

Any help?

CodePudding user response：

Change the type of the Status property of the Record class to status (the enum type) or set the ItemsSource property of the ComboBox to an IEnumerable<string>:

public override object ProvideValue(IServiceProvider serviceProvider)
{
    return Enum.GetValues(EnumType).Cast<object>().Select(x => x.ToString());
}

The types must match. You cannot set a string property to an enumeration (enum) value.