Hi Marc,

I performed a test based on your description. I didn't reproduce the
problem of a phantom empty row appearing in the DataGridView when a new
item is added into the data source.

In my test, I set the AllowUserToAddRows property of the DataGridView to
true and call the AddNew method of the BindingSource to add a new item into
the data source. After I call the BindingSource.AddNew method for the first
time, the rows count in the BindingSource is 1 and that in the DataGridView
is 2. The added row appears at the top of the DataGridView and the "new
row" entry is at the bottom.

The following is the code in my test. It requires a DataGridView and a
Button are added onto the Form1.

public partial class Form1 : Form
{
       public Form1()
       {          
           InitializeComponent();          
       }
       List<Person> lists = new List<Person>();
       BindingSource bs = new BindingSource();

       private void Form1_Load(object sender, EventArgs e)
       {
           this.dataGridView1.AllowUserToAddRows = true;
           bs.DataSource = lists;
           this.dataGridView1.DataSource = bs;

           Console.WriteLine("load-dgv row count:" +
this.dataGridView1.Rows.Count.ToString());
           Console.WriteLine("load-binding source:" + bs.Count.ToString());
       }      

       private void button1_Click(object sender, EventArgs e)
       {            
           bs.AddNew();
           Console.WriteLine("datagridview row count:"
+this.dataGridView1.Rows.Count.ToString());
           Console.WriteLine("binding source:" + bs.Count.ToString());
       }

       class Person
       {
           private int id;
           private string name;
           public int ID
           {
               get { return id; }
               set { id = value; }
           }
           public string Name
           {
               get { return name; }
               set { name = value; }
           }                      
       }        
}

You may test the above sample code on your side to see if you get the same
result. You may also have a try removing the existing DataGridView on your
form and adding a new one to see if the problem still exists.

Hope this helps.

Sincerely,
Linda Liu
Microsoft Online Community Support

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