unauthorized when i want to load data from a list of a site

Question

hello

 i want to load data from a sharepoint site. I also give my username and password but it is said it is unauthorized, below is my code, can you help me pelase?thank you

 

  tring siteUrl = "the name of my sharepointsite";                            ClientContext clientContext = new ClientContext(siteUrl);                            clientContext.AuthenticationMode = ClientAuthenticationMode.FormsAuthentication;                            clientContext.FormsAuthenticationLoginInfo = new FormsAuthenticationLoginInfo("myusername", "mypassword");                        List oList = clientContext.Web.Lists.GetByTitle(item.Header);                        CamlQuery query = CamlQuery.CreateAllItemsQuery(100);                        //CamlQuery camlQuery = new CamlQuery();                        // camlQuery.ViewXml = "<View><RowLimit>100</RowLimit></View>";                        ListItemCollection collListItem = oList.GetItems(query);                            clientContext.Load(collListItem);                            clientContext.ExecuteQuery();                            foreach (ListItem oListItem in collListItem)                            {                               mylist.mydynamicgrid.RowDefinitions.Add(new RowDefinition                          {                              Height = new GridLength(1, GridUnitType.Auto),                              Tag = item                          });                            }