Handle Add, Delete and Update of Rows

Updated over 6 months ago

When the user adds new rows, updates or deletes the existing ones, the external data source should be updated as well. Follow the steps below in order to keep the data synced:

1. Handle the CellValuePushed event in order to detect when a cell value is changed.

Push value to the data source

C#

    
private void radVirtualGrid1_CellValuePushed(object sender, VirtualGridCellValuePushedEventArgs e)
{
    this.UpdateCellValue(data[e.RowIndex].CustomerId, columnNames[e.ColumnIndex], Convert.ToString(e.Value));
}
    
private void UpdateCellValue(string id, string columnName, string value)
{
    using (System.Data.OleDb.OleDbCommand command = new System.Data.OleDb.OleDbCommand(@"UPDATE Customers SET " + columnName + " = ? WHERE CustomerID = ?"))
    {
        command.Parameters.Add(new System.Data.OleDb.OleDbParameter("@columnValue", value));
        command.Parameters.Add(new System.Data.OleDb.OleDbParameter("@customerId", id));
        command.Connection = new System.Data.OleDb.OleDbConnection(connectionString);
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();
    }
    SelectData();
}

VB.NET

Private Sub radVirtualGrid1_CellValuePushed(sender As Object, e As VirtualGridCellValuePushedEventArgs)
    Me.UpdateCellValue(data(e.RowIndex).CustomerId, columnNames(e.ColumnIndex), Convert.ToString(e.Value))
End Sub
Private Sub UpdateCellValue(id As String, columnName As String, value As String)
    Using command As New System.Data.OleDb.OleDbCommand((Convert.ToString("UPDATE Customers SET ") & columnName) + " = ? WHERE CustomerID = ?")
        command.Parameters.Add(New System.Data.OleDb.OleDbParameter("@columnValue", value))
        command.Parameters.Add(New System.Data.OleDb.OleDbParameter("@customerId", id))
        command.Connection = New System.Data.OleDb.OleDbConnection(connectionString)
        command.Connection.Open()
        command.ExecuteNonQuery()
        command.Connection.Close()
    End Using
    SelectData()
End Sub

2. When the user adds a new row in the grid, it is necessary to subscribe to the UserAddedRow event in order to update the data source:

Add new row

C#

        
private void radVirtualGrid1_UserAddedRow(object sender, VirtualGridNewRowEventArgs e)
{
    List<object> newValues = new List<object>();
    for (int i = 0; i < columnNames.Length; i++)
    {
        newValues.Add(e.NewValues[i]);
    }
    this.AddDataRow(newValues);
}
        
private void AddDataRow(List<object> newValues)
{
    using (OleDbCommand command = new OleDbCommand(@"INSERT INTO Customers (CustomerID, CompanyName," +
                                                   " ContactName, ContactTitle, Address, PostalCode)  values (?, ?, ?, ?, ?, ?)"))
    {
        command.Parameters.Add(new OleDbParameter("@param1", GenerateID()));
        command.Parameters.Add(new OleDbParameter("@param2", newValues[0]));
        command.Parameters.Add(new OleDbParameter("@param3", newValues[1]));
        command.Parameters.Add(new OleDbParameter("@param4", newValues[2]));
        command.Parameters.Add(new OleDbParameter("@param5", newValues[3]));
        command.Parameters.Add(new OleDbParameter("@param6", newValues[4]));
        command.Connection = new OleDbConnection(connectionString);
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();
    }
    int currentColumn = this.radVirtualGrid1.VirtualGridElement.CurrentCell.ColumnIndex;
    SelectData();
    this.radVirtualGrid1.VirtualGridElement.InputBehavior.SelectCell(data.Count - 1, currentColumn, false,
        false, this.radVirtualGrid1.VirtualGridElement.MasterViewInfo);
}
        
private string GenerateID()
{
    StringBuilder sb = new StringBuilder();
    Random rand = new Random();
    for (int i = 0; i < 5; i++)
    {
        sb.Append((char)('A' + rand.Next(26)));
    }
    return sb.ToString();
}

VB.NET

Private Sub radVirtualGrid1_UserAddedRow(sender As Object, e As VirtualGridNewRowEventArgs)
    Dim newValues As New List(Of Object)()
    For i As Integer = 0 To columnNames.Length - 1
        newValues.Add(e.NewValues(i))
    Next
    Me.AddDataRow(newValues)
End Sub
Private Sub AddDataRow(newValues As List(Of Object))
    Using command As New OleDbCommand("INSERT INTO Customers (CustomerID, CompanyName," + _
    " ContactName, ContactTitle, Address, PostalCode)  values (?, ?, ?, ?, ?, ?)")
        command.Parameters.Add(New OleDbParameter("@param1", GenerateID()))
        command.Parameters.Add(New OleDbParameter("@param2", newValues(0)))
        command.Parameters.Add(New OleDbParameter("@param3", newValues(1)))
        command.Parameters.Add(New OleDbParameter("@param4", newValues(2)))
        command.Parameters.Add(New OleDbParameter("@param5", newValues(3)))
        command.Parameters.Add(New OleDbParameter("@param6", newValues(4)))
        command.Connection = New OleDbConnection(connectionString)
        command.Connection.Open()
        command.ExecuteNonQuery()
        command.Connection.Close()
    End Using
    Dim currentColumn As Integer = Me.radVirtualGrid1.VirtualGridElement.CurrentCell.ColumnIndex
    SelectData()
    Me.radVirtualGrid1.VirtualGridElement.InputBehavior.SelectCell(data.Count - 1, currentColumn, _
                                                                   False, False, Me.radVirtualGrid1.VirtualGridElement.MasterViewInfo)
End Sub
Private Function GenerateID() As String
    Dim sb As New StringBuilder()
    Dim rand As New Random()
    For i As Integer = 0 To 4
        sb.Append(CChar(ChrW(Asc("A") + rand.[Next](26))))
    Next
    Return sb.ToString()
End Function

3. When the user deletes an existing row, you should handle the UserDeletingRow event to update the data source as well:

Delete row

C#

        
private void radVirtualGrid1_UserDeletedRow(object sender, VirtualGridRowsEventArgs e)
{
    string query = "";
    foreach (var item in e.RowIndices)
    {
        query += "'" + data[item].CustomerId + "',";
    }
    DeleteDataRow(query.TrimEnd(','));
}
private void DeleteDataRow(string query)
{
    using (OleDbCommand command = new OleDbCommand("DELETE FROM Customers where CustomerID In  (" + query + ")"))
    {
        command.Connection = new OleDbConnection(connectionString);
        command.Connection.Open();
        command.ExecuteNonQuery();
        command.Connection.Close();
    }
    SelectData();
}

VB.NET

Private Sub radVirtualGrid1_UserDeletedRow(sender As Object, e As VirtualGridRowsEventArgs)
    Dim query As String = ""
    For Each item As Integer In e.RowIndices
        query += "'" + data(item).CustomerId + "',"
    Next
    DeleteDataRow(query.TrimEnd(","c))
End Sub
    
Private Sub DeleteDataRow(query As String)
    Using command As New OleDbCommand((Convert.ToString("DELETE FROM Customers where CustomerID In  (") & query) + ")")
        command.Connection = New OleDbConnection(connectionString)
        command.Connection.Open()
        command.ExecuteNonQuery()
        command.Connection.Close()
    End Using
    SelectData()
End Sub

See Also

• Populating with Data