重新加载页面时出现数据网格错误

Question

我有一个添加客户 UI，它应用了一个数据网格来显示提供的条目，但是如果我在已经显示的同时重新选择添加客户，它将再次添加条目。第 1-3 行是原始行，第 4-6 行是重复行。有谁知道如何限制这种情况的发生？在我的 MainActivity 中，我有一个带有 Frame 的菜单导航来填充 xaml 页面。下面是初始化类的代码。private void AddCustomer_Click(object sender, RoutedEventArgs e){    Main.Content = new AddCustomerUI();}Frame 被称为 Main，然后将 xaml 页面分配给它的 Main.contentpublic partial class AddCustomerUI : Page{    public AddCustomerUI()    {        InitializeComponent();        SetupCustomer();        customerDataGrid.ItemsSource = App.customers;    }    private void SetupCustomer()    {        var customer = new Customer { FirstName = "Timothy", LastName = "Jennings", Email = "[e-mail]", Phone = "0275 202020",            Address = new Address { Street = "100 Burt Road", Suburb = "Howick", City = "Auckland", Country = "New Zealand" }        };        App.customers.Add(customer);        customer = new Customer { FirstName = "Brian", LastName = "Jones", Email = "[e-mail]", Phone = "0275 903070",            Address = new Address { Street = "100 Vincent Road", Suburb = "St Lukes", City = "Auckland", Country = "New Zealand" }        };        App.customers.Add(customer);        App.customers.Add(new Customer { FirstName = "Terry", LastName = "Teo", Email = "[e-mail]", Phone = "021 756 382",            Address = new Address { Street = "23 Ford St", City = "Auckland", Suburb = "Pakuranga", Country = "New Zealand" }        });    }

Answer 1

您遇到的问题是SetupCustomer，您没有清除列表，因此您的收藏中有多个条目。

private void SetupCustomer()

{

    App.customers.Clear();

    var customer = new Customer { FirstName = "Timothy", LastName = "Jennings", Email = "[e-mail]", Phone = "0275 202020",

     Address = new Address { Street = "100 Burt Road", Suburb = "Howick", City = "Auckland", Country = "New Zealand" }

        };

     App.customers.Add(customer);

     customer = new Customer { FirstName = "Brian", LastName = "Jones", Email = "[e-mail]", Phone = "0275 903070",

     Address = new Address { Street = "100 Vincent Road", Suburb = "St Lukes", City = "Auckland", Country = "New Zealand" }

        };

     App.customers.Add(customer);

     App.customers.Add(new Customer { FirstName = "Terry", LastName = "Teo", Email = "[e-mail]", Phone = "021 756 382",

     Address = new Address { Street = "23 Ford St", City = "Auckland", Suburb = "Pakuranga", Country = "New Zealand" }

     });

}

Answer 2

在您SetupCustomer的课堂方法中，AddCustomerUI在开始时添加

 App.customers.Clear();

这应该有助于您的重复数据。