如何将客户列表转换为Winforms应用程序？(How do I get customer list into a winforms app?)

如何将客户列表转换为Winforms应用程序？(How do I get customer list into a winforms app?)

我正试图从Customers.cs获取一个客户列表到MainForm.cs 。 有没有办法从Customers.cs获取列表而不使用sql server？ 我希望它显示列名colFirstName下的名字和MainForm.cs colLastName名colLastName下的最后一个名字。 我有一个代码用于MainForm.cs以获取sql客户列表，但我需要在不使用sql连接的情况下获取客户列表。

Customers.cs代码

using System; using System.Collections.Generic; using System.ComponentModel.DataAnnotations; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ClassProject2.Data { public class Customers { public Customers() { _customers = new List<Customer>() //Customer list { new Customer(_ids.Next()) { FirstName = "Bob", LastName = "Miller" }, new Customer(_ids.Next()) { FirstName = "Sue", LastName = "Storm" }, new Customer(_ids.Next()) { FirstName = "Peter", LastName = "Parker" } }; } public Customer Add ( Customer customer ) { if (customer == null) throw new ArgumentNullException(nameof(customer)); Validator.ValidateObject(customer, new ValidationContext(customer)); if (_customers.Any(c => String.Compare(c.FirstName, customer.FirstName, true) == 0 && String.Compare(c.LastName, customer.LastName, true) == 0)) throw new ArgumentException("Customer already exists.", nameof(customer)); customer.Id = _ids.Next(); _customers.Add(customer); return customer; } public Customer Get ( int id ) { return (from c in _customers where id == c.Id select c ).FirstOrDefault(); } public IEnumerable<Customer> GetAll () { return _customers; } public void Remove(int id) { //Verify > 0 if (id <= 0) throw new ArgumentOutOfRangeException("Id must be > 0", nameof(id)); //Find the item var item = _customers.FirstOrDefault(i => i.Id == id); //Remove it if (item != null) _customers.Remove(item); } private readonly List<Customer> _customers; private readonly Sequence _ids = new Sequence(100); } }

我用于MainForm.cs代码

private void IsLinkClicked(MouseEventArgs e) { try { if (e.Button != MouseButtons.Left) return; DataGridView.HitTestInfo Hti = gridCustomers.HitTest(e.X, e.Y); if (Hti.Type == DataGridViewHitTestType.Cell) { if (gridCustomers.Rows.Count > 0) { gridCustomers.CurrentCell = gridCustomers[Hti.ColumnIndex, Hti.RowIndex]; } } if(Hti.ColumnIndex < 0 || Hti.ColumnIndex > gridCustomers.ColumnCount) { value = false; } CustomerForm cf = new CustomerForm(); cf.editMode = true; int rowIndex = gridCustomers.CurrentCell.RowIndex; cf.id = gridCustomers.Rows[rowIndex].Cells["colId"].Value.ToString(); cf.FName = gridCustomers.Rows[rowIndex].Cells["colFirstName"].Value.ToString(); cf.LName = gridCustomers.Rows[rowIndex].Cells["colLastName"].Value.ToString(); cf.Show(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }

I am trying to get a customer list from Customers.cs into MainForm.cs. Is there a way to get the list from Customers.cs without using a sql server? I want it to show the first name under the column name colFirstName and the last name under the column name colLastName on the MainForm.cs. I have a code that I used for MainForm.cs to get the sql customer list, but I am required to get the customer list without using a sql connection.

Customers.cs code

using System; using System.Collections.Generic; using System.ComponentModel.DataAnnotations; using System.Linq; using System.Text; using System.Threading.Tasks; namespace ClassProject2.Data { public class Customers { public Customers() { _customers = new List<Customer>() //Customer list { new Customer(_ids.Next()) { FirstName = "Bob", LastName = "Miller" }, new Customer(_ids.Next()) { FirstName = "Sue", LastName = "Storm" }, new Customer(_ids.Next()) { FirstName = "Peter", LastName = "Parker" } }; } public Customer Add ( Customer customer ) { if (customer == null) throw new ArgumentNullException(nameof(customer)); Validator.ValidateObject(customer, new ValidationContext(customer)); if (_customers.Any(c => String.Compare(c.FirstName, customer.FirstName, true) == 0 && String.Compare(c.LastName, customer.LastName, true) == 0)) throw new ArgumentException("Customer already exists.", nameof(customer)); customer.Id = _ids.Next(); _customers.Add(customer); return customer; } public Customer Get ( int id ) { return (from c in _customers where id == c.Id select c ).FirstOrDefault(); } public IEnumerable<Customer> GetAll () { return _customers; } public void Remove(int id) { //Verify > 0 if (id <= 0) throw new ArgumentOutOfRangeException("Id must be > 0", nameof(id)); //Find the item var item = _customers.FirstOrDefault(i => i.Id == id); //Remove it if (item != null) _customers.Remove(item); } private readonly List<Customer> _customers; private readonly Sequence _ids = new Sequence(100); } }

Code that I used for MainForm.cs

private void IsLinkClicked(MouseEventArgs e) { try { if (e.Button != MouseButtons.Left) return; DataGridView.HitTestInfo Hti = gridCustomers.HitTest(e.X, e.Y); if (Hti.Type == DataGridViewHitTestType.Cell) { if (gridCustomers.Rows.Count > 0) { gridCustomers.CurrentCell = gridCustomers[Hti.ColumnIndex, Hti.RowIndex]; } } if(Hti.ColumnIndex < 0 || Hti.ColumnIndex > gridCustomers.ColumnCount) { value = false; } CustomerForm cf = new CustomerForm(); cf.editMode = true; int rowIndex = gridCustomers.CurrentCell.RowIndex; cf.id = gridCustomers.Rows[rowIndex].Cells["colId"].Value.ToString(); cf.FName = gridCustomers.Rows[rowIndex].Cells["colFirstName"].Value.ToString(); cf.LName = gridCustomers.Rows[rowIndex].Cells["colLastName"].Value.ToString(); cf.Show(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }

最满意答案

我不认为有可能在没有连接到数据库的情况下获取列表，而是尝试从中提取数据。

你可以使用dataAdapter和一个数据集来处理未连接模式在数据集中，如果你不想修改数据库和只显示数据给用户，你只能放置SELECT语句

I don't think it is possible to Get The list without having a connection to the database you're trying to pull data out of.

you can do it with dataAdapter and a Dataset to be in Unconnected Mode In your dataset you can only put SELECT statement if you don't want to modify the database and Just Show Data to the User