Updating of BindingSource in WinForms does not update Datasource Collection

Question

I want to display a custom collection in a DataGridView in a Windows Forms app. This custom collection implements ICollection, and IEnumerable

Answer 1

The problem is Fill Adaptor. When you load your form, the Fill is done for you. Just make sure to do a Refill and then follow up with Reset bindings post any data changes and Grid will get refreshed.

Example :

WorkTableAdapter.Insert(objData.XAttribute, "",
  objData.YAttribute,objLoanData.Amount_IsValid, DateTime.Now, DateTime.Now);
this.WorkTableAdapter.Fill(this.POCDataSet.Work);
this.WorkBindingSource.ResetBindings(false);

Answer 2

Resetting an individual item works!

I had no luck with .ResetBindings(false) and re-assigning the datsource caused flickering with potentiail overhead if only one item change frequently.

I tried the built in mechanism using PropertyChanged but nothing updated.

Reseting an individual item using ResetItem() worked!

        for (int i = 0; i < bindingSource1.Count; i++)
        {
            bindingSource1.ResetItem(i);   
        }

And even better - if you have an update event attached to each data item in the bindningsource you can locate the object in the bindning source and use the index of the object to call ResetItem(idx)

In this case my custom event args contains a dictionary key to the data object contained in a separate collection. After object is located in using bindningsource.IndexOf() it is individually refreshed.

    void Value_PropertyChanged(object sender, RegisterEventArgs e)
    {

        var idx = bindingSource1.IndexOf(registers_ref[e.registerID]);
        if (idx>=0)
        {
            bindingSource1.ResetItem(idx);                
        }

    }

Answer 3

You will have to manually call ResetBindings() after the data source changes if you use a container that cannot do that on your behalf.

http://msdn.microsoft.com/en-us/library/system.windows.forms.bindingsource.resetbindings.aspx

Causes a control bound to the BindingSource to reread all the items in the list and refresh their displayed values.

Answer 4

I believe I ran into this issue a while ago - I did a find in files on my code and I think this is the solution that worked for me.

        // Applies pending changes to the underlying data source.
        this.bindingSource1.EndEdit();

This was in the context of a click handler for the save button.