This is a request.  I am on a team writing a Window Forms project using databinding and ES.  The combination works great.  The only issue currently is when there are no rows in the collection and I want to add the first.

 What is the best practice for adding the first row?

Here is my current code:

On form load::

    moCustomers = New HJ.DataAccess.CustomersCollection
    With moCustomers.Query
      .OrderBy( _
        .CustomerName.Ascending _
      )
      .Load()
    End With

    Me.CustomersCollectionBindingSource.DataSource = moCustomers

When the add new button is clicked::

	Me.ContactsCollectionBindingSource.AddNew()

When the save button is clicked::

	Me.ContactsCollectionBindingSource.EndEdit()

	moContacts.Save()

Glenn,

Did you solve this problem? I have just run into the same thing and can't fugure why, it was working, or so I thought!

I have now created a clean test project to try and see what is wrong. It uses a simple table in Nwind -  sql create below.

Using:

EntitySpaces Version # 2007.0.0304.0
MyGeneration Version # 1.2.0.2

I have also used 1.5.3 and see no difference.

If the table contains no rows the first row added will be blank. Adding more rows works just fine. The problem seems to be that the current row on the bindingsource is at -1 after the addNew and not at position 0 as it seems to expect. Why might the binding source not reposition to the added row after the AddNew?

In the interest of simplicity, I have no binding navigator, just a few buttons.

Declan

1    Imports EntitySpaces.Core
2    Imports EntitySpaces.Interfaces
3    
4    Imports ES_NorthWind.BusinessObjects
5    
6    Public Class DataBindingTest
7    
8    
9        Dim collNewCustomers As NewCustomersCollection = New NewCustomersCollection
10   
11       Private Sub DataBindingTest_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
12   
13           collNewCustomers.LoadAll()
14           Me.NewCustomersCollectionBindingSource.DataSource = collNewCustomers
15   
16       End Sub
17   
18       Private Sub addNewItem()
19           NewCustomersCollectionBindingSource.AddNew()
20       End Sub
21   
22       Private Sub saveItem()
23   
24           ShowPosition()
25   
26           NewCustomersCollectionBindingSource.EndEdit()
27           collNewCustomers.Save()
28       End Sub
29   
30       Private Sub deleteItem()
31   
32           ShowPosition()
33   
34           NewCustomersCollectionBindingSource.RemoveCurrent()
35           collNewCustomers.Save()
36       End Sub
37   
38       Private Sub ShowPosition()
39           Console.WriteLine("Count {0}; Position {1}", NewCustomersCollectionBindingSource.CurrencyManager.Count, _
40                                                NewCustomersCollectionBindingSource.CurrencyManager.Position)
41   
42       End Sub
43   
44       Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
45           Me.NewCustomersCollectionBindingSource.MoveFirst()
46       End Sub
47   
48       Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
49           Me.NewCustomersCollectionBindingSource.MovePrevious()
50       End Sub
51   
52       Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
53           Me.NewCustomersCollectionBindingSource.MoveNext()
54       End Sub
55   
56       Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
57           Me.NewCustomersCollectionBindingSource.MoveLast()
58       End Sub
59   
60       Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
61           addNewItem()
62       End Sub
63   
64       Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
65           deleteItem()
66       End Sub
67   
68       Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
69           saveItem()
70       End Sub
71   End Class

1    USE [NorthWind]
2    GO
3    /****** Object:  Table [dbo].[NewCustomers]    Script Date: 03/08/2007 16:52:52 ******/
4    SET ANSI_NULLS ON
5    GO
6    SET QUOTED_IDENTIFIER ON
7    GO
8    CREATE TABLE [dbo].[NewCustomers](
9    	[CustomerID] [int] IDENTITY(1,1) NOT NULL,
10   	[CompanyName] [nvarchar](40) COLLATE Latin1_General_CI_AI NULL,
11   	[ContactName] [nvarchar](30) COLLATE Latin1_General_CI_AI NULL,
12    CONSTRAINT [PK_NewCustomers] PRIMARY KEY CLUSTERED 
13   (
14   	[CustomerID] ASC
15   )WITH (PAD_INDEX  = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
16   ) ON [PRIMARY]

Why does this always happen just after I post a cry for help? I guess I need a site of my own somewhere where I can blow off steam for a while.

I found a solution, though I am surprised I need this.

Adding ResetBindings immediately after the AddNew seems to solve the problem

Declan

1        Private Sub addNewItem()
2            NewCustomersCollectionBindingSource.AddNew()
3    
4            NewCustomersCollectionBindingSource.ResetBindings(False)
5    
6        End Sub