Hi All,

First of all sorry for the long post. I Just started to play around with the
datagridview. I found an example on msdn (see code below) but there are two
things I really don't understand.

1: Instead of two columns, one with 'Company Name' and one with 'Contact
Name', I get four columns. Both colums are displayed twice.

2: When I run the sample and I delete the the second row, the two rows that
are left are diplaying the same content.

I having a hard time to figure out why this is happening en would really
appreciate it when someone could help me out here.

Thank a lot in advance,

Bart

Here is the code:

namespace DataListViewTest
{
   public partial class Form1: Form
   {
       private DataGridView dataGridView1 = new DataGridView();

       // Declare an ArrayList to serve as the data store.
       //private ArrayList customers = new ArrayList();
       private List<Customer> customers = new List<Customer>();

       // Declare a Customer object to store data for a row being edited.
       private Customer customerInEdit;

       // Declare a variable to store the index of a row being edited.
       // A value of -1 indicates that there is no row currently in edit.
       private int rowInEdit = -1;

       // Declare a variable to indicate the commit scope.
       // Set this value to false to use cell-level commit scope.
       private bool rowScopeCommit = true;

       public Form1()
       {
           InitializeComponent();

           dataGridView1.Dock = DockStyle.Fill;
           Controls.Add(this.dataGridView1);
           Load += new EventHandler(Form1_Load);
           Text = "DataGridView virtual-mode demo (row-level commit
scope)";
       }

       private void Form1_Load(object sender, EventArgs e)
       {
           // Enable virtual mode.
           dataGridView1.VirtualMode = true;

           // Connect the virtual-mode events to event handlers.
           dataGridView1.CellValueNeeded += new
               DataGridViewCellValueEventHandler(dataGridView1_CellValueNeeded);
           dataGridView1.CellValuePushed += new
               DataGridViewCellValueEventHandler(dataGridView1_CellValuePushed);
           dataGridView1.NewRowNeeded += new
               DataGridViewRowEventHandler(dataGridView1_NewRowNeeded);
           dataGridView1.RowValidated += new
               DataGridViewCellEventHandler(dataGridView1_RowValidated);
           dataGridView1.RowDirtyStateNeeded += new
               QuestionEventHandler(dataGridView1_RowDirtyStateNeeded);
           dataGridView1.CancelRowEdit += new
               QuestionEventHandler(dataGridView1_CancelRowEdit);
           dataGridView1.UserDeletingRow += new
               DataGridViewRowCancelEventHandler(dataGridView1_UserDeletingRow);

           // Add columns to the DataGridView.
           DataGridViewTextBoxColumn companyNameColumn = new
DataGridViewTextBoxColumn();
           companyNameColumn.HeaderText = "Company Name";
           companyNameColumn.Name = "Company Name";

           DataGridViewTextBoxColumn contactNameColumn = new
DataGridViewTextBoxColumn();
           contactNameColumn.HeaderText = "Contact Name";
           contactNameColumn.Name = "Contact Name";

           dataGridView1.Columns.Add(companyNameColumn);
           dataGridView1.Columns.Add(contactNameColumn);
           dataGridView1.AutoSizeColumnsMode =
DataGridViewAutoSizeColumnsMode.AllCells;

           // Add some sample entries to the data store.
           customers.Add(new Customer("Bon app'", "Laurence Lebihan"));
           customers.Add(new Customer("Bottom-Dollar Markets", "Elizabeth
Lincoln"));
           customers.Add(new Customer("B's Beverages", "Victoria
Ashworth"));

           // Set the row count, including the row for new records.
           dataGridView1.RowCount = 4;
       }

      private void dataGridView1_CellValueNeeded(object sender,
DataGridViewCellValueEventArgs e)
       {
           // If this is the row for new records, no values are needed.
           if (e.RowIndex == this.dataGridView1.RowCount - 1) return;

           Customer customerTmp = null;

           // Store a reference to the Customer object for the row being
painted.
           if (e.RowIndex == rowInEdit)
           {
               customerTmp = this.customerInEdit;
           }
           else
           {
               customerTmp = (Customer)this.customers[e.RowIndex];
           }

           // Set the cell value to paint using the Customer object
retrieved.
           switch (this.dataGridView1.Columns[e.ColumnIndex].Name)
           {
               case "Company Name":
                   e.Value = customerTmp.CompanyName;
                   break;

               case "Contact Name":
                   e.Value = customerTmp.ContactName;
                   break;
           }
       }

       private void dataGridView1_CellValuePushed(object sender,
DataGridViewCellValueEventArgs e)
       {
           Customer customerTmp = null;

           // Store a reference to the Customer object for the row being
edited.
           if (e.RowIndex < customers.Count)
           {
               // If the user is editing a new row, create a new Customer
object.
               if (customerInEdit == null)
               {
                   customerInEdit = new Customer(
                       ((Customer)customers[e.RowIndex]).CompanyName,
                       ((Customer)customers[e.RowIndex]).ContactName);
               }
               customerTmp = customerInEdit;
               rowInEdit = e.RowIndex;
           }
           else
           {
               customerTmp = customerInEdit;
           }

           // Set the appropriate Customer property to the cell value
entered.
           String newValue = e.Value as String;
           switch (dataGridView1.Columns[e.ColumnIndex].Name)
           {
               case "Company Name":
                   customerTmp.CompanyName = newValue;
                   break;

               case "Contact Name":
                   customerTmp.ContactName = newValue;
                   break;
           }
       }

       private void dataGridView1_NewRowNeeded(object sender,
DataGridViewRowEventArgs e)
       {
           // Create a new Customer object when the user edits
           // the row for new records.
           customerInEdit = new Customer();
           rowInEdit = dataGridView1.Rows.Count - 1;
       }

       private void dataGridView1_RowValidated(object sender,
DataGridViewCellEventArgs e)
       {
           // Save row changes if any were made and release the edited
           // Customer object if there is one.
           if (e.RowIndex >= customers.Count &&
               e.RowIndex != dataGridView1.Rows.Count - 1)
           {
               // Add the new Customer object to the data store.
               customers.Add(customerInEdit);
               customerInEdit = null;
               rowInEdit = -1;
           }
           else if (customerInEdit != null &&
               e.RowIndex < customers.Count)
           {
               // Save the modified Customer object in the data store.
               customers[e.RowIndex] = customerInEdit;
               customerInEdit = null;
               rowInEdit = -1;
           }
           else if (dataGridView1.ContainsFocus)
           {
               customerInEdit = null;
               rowInEdit = -1;
           }
       }

       private void dataGridView1_RowDirtyStateNeeded(object sender,
QuestionEventArgs e)
       {
           if (!rowScopeCommit)
           {
               // In cell-level commit scope, indicate whether the value
               // of the current cell has been modified.
               e.Response = dataGridView1.IsCurrentCellDirty;
           }
       }

       private void dataGridView1_CancelRowEdit(object sender,
QuestionEventArgs e)
       {
           if (rowInEdit == dataGridView1.Rows.Count - 2 && rowInEdit ==
customers.Count)
           {
               // If the user has canceled the edit of a newly created row,
               // replace the corresponding Customer object with a new,
empty one.
               customerInEdit = new Customer();
           }
           else
           {
               // If the user has canceled the edit of an existing row,
               // release the corresponding Customer object.
               customerInEdit = null;
               rowInEdit = -1;
           }
       }

       private void dataGridView1_UserDeletingRow(object sender,
DataGridViewRowCancelEventArgs e)
       {
           if (e.Row.Index < customers.Count)
           {
               // If the user has deleted an existing row, remove the
               // corresponding Customer object from the data store.
               customers.RemoveAt(e.Row.Index);
           }

           if (e.Row.Index == rowInEdit)
           {
               // If the user has deleted a newly created row, release
               // the corresponding Customer object.
               rowInEdit = -1;
               customerInEdit = null;
           }
       }
   }
}

===============================================================================

namespace DataListViewTest
{
   public class Customer
   {
       private String companyNameValue;
       private String contactNameValue;

       public Customer()
       {
           // Leave fields empty.
       }

       public Customer(String companyName, String contactName)
       {
           companyNameValue = companyName;
           contactNameValue = contactName;
       }

       public String CompanyName
       {
           get{ return companyNameValue; }
           set{ companyNameValue = value; }
       }

       public String ContactName
       {
           get{ return contactNameValue; }
           set{ contactNameValue = value; }
       }
   }
}