CODEWITHSUNDEEP
c#winformsbinding
Kirsten
Kirsten

Reputation: 18056

notifying bindingSource.position. Using 2 way binding in winforms to select the current record

I have a bindingSource in winforms as well as a controller class. I want to be able to set the selected record from within the controller class using 2 way binding. That is If the form is displaying and I set the SelectedPerson in the controller then the bindingSOurce should make that person the current record.

My controller code is 

public class PeopleController : BaseController
{
    private SortableBindingList<Person> _blvPersons;
    public SortableBindingList<Person> BlvPersons
    {
        get
        {
            return this._blvPersons;
        }
        set
        {
            this._blvPersons = value;
            this.SendChange("BlvPersons");
        }
    }

    private Person _selectedPerson;

    public Person SelectedPerson
    {
        get
        {
            return this._selectedPerson;
        }
        set
        {
            this._selectedPerson = value;
            this.SendChange("SelectedPerson");
            this.SendChange("BlvPersons");
            this.Trace("## SelectedPerson = {0}", value);
        }
    }

   public void InitBindingList
    {
        using (var repo = new PeopleRepository(new OrganisationContext()))
        {
                IList<Person> lst = repo.GetList(p => p.Id > 0 && p.Archived == false, x => x.Organisation);

                this.BlvPersons = new SortableBindingList<Person>(lst);


        } }
    }
   //ect
 }


public class BaseController : INotifyPropertyChanged, IDisposable
{
    public event PropertyChangedEventHandler PropertyChanged;

    public void SendChange(string propertyName)
    {
        System.Diagnostics.Debug.WriteLine("PropertyChanged {0} = {1}", propertyName, GetType().GetProperty(propertyName).GetValue(this, null));

        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

 // etc

I have a bindingSource on my form and set bindingSource.DataSource = controller.BlvPersons

If I Update data values using the controller I will see these changes in the form. However I cant work out how to set the current record in the controller and see the change in the form.

Upvotes: 0

Views: 837

Answers (2)

Kirsten
Kirsten

Reputation: 18056

Because I don't want a winforms reference in my controller class, I don't want to share the bindingSource between the form and the controller.

Instead I came up with the idea of having a RecordPosition property in the controller and binding it to a textbox

In my form I have

BindHelper.BindText(this.textRecordPosition,this.controller,"RecordPosition");

private void textRecordPosition_TextChanged(object sender, EventArgs e)
    {
        this.bindingSource.Position = Convert.ToInt32(textRecordPosition.Text) -1;
    }

private void bindingSource_PositionChanged(object sender, EventArgs e)
    {
        this.controller.RecordPosition = this.bindingSource.Position + 1;
    }

In my controller I have

    public int RecordPosition
    {
        get
        {
            return this._position;
        }

        set
        {
            this._position = value;
            this.SendChange("RecordPosition");
        }
    }

In my BindHelper class I have

public static void BindText(TextBox box, object dataSource, string dataMember)
    {
        var bind = new Binding("Text", dataSource, dataMember, true, DataSourceUpdateMode.OnPropertyChanged);
        box.DataBindings.Add(bind);
    }

Upvotes: 0

Jacob Seleznev
Jacob Seleznev

Reputation: 8131

You can use BindingSource.Find method and set the Position property to the results of the Find method.

The Find method can only be used when the underlying list is an IBindingList with searching implemented. This method simply refers the request to the underlying list's IBindingList.Find method.

To implement search on a generic BindingList requires various steps. First, you have to indicate that searching is supported by overriding the SupportsSearchingCore property. Next, you have to implement the IBindingList.Find method, which performs the search.

You can use examples from here or here.

Upvotes: 1

Related Questions