winform中的datagridview，columncombobox值变化

Question

我正在设计一个 winform，其中我有一个带有预定义列的 datagridview，第一列是组合框，其余 3 列是文本框。 我没有将 datagridview 绑定到任何数据源，因为用户要填充最后一列“数量”，我想要实现的是，当用户单击组合框时，它应该显示数据库表中的 3 列（项目代码、项目名称和 uom），当用户选择任何特定的“项目代码”时，对应的“项目名称”和“uom”应显示在 datagridview 的第二列和第三列。同样，用户应该能够根据需要输入尽可能多的行。数据输入后，数据将保存在名为“采购申请”的表中。 到目前为止，我还没有进行任何编码，只设计了表单。

Answer 1

看看下面的代码是否会提供滚动的基本代码。有几个类可以模拟数据和一个扩展方法，应该移动到自己的文件中。

DataGridView 没有在设计器中配置，只是在代码中。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace UnboundDataGridViewComboBox
{
    public partial class Form1 : Form
    {

        private ComboBox _cbo;
        private string _comboColumnName = "ItemCodeColumn";
        private List<Item> _items => Mocked.Items;
        
        public Form1()
        {
            InitializeComponent();
            Shown += OnShown;
        }

        private void OnShown(object sender, EventArgs e)
        {
            var column1 = new DataGridViewComboBoxColumn
            {
                DataSource = _items.Select(x => x.ItemCode).ToArray(),
                DisplayStyle = DataGridViewComboBoxDisplayStyle.Nothing,
                Name = _comboColumnName,
                HeaderText = "Item Code",
                SortMode = DataGridViewColumnSortMode.NotSortable
            };

            var column2 = new DataGridViewTextBoxColumn
            {
                Name = "ItemNameColumn",
                HeaderText = "Item Name"
            };
            var column3 = new DataGridViewTextBoxColumn
            {
                Name = "UomColumn",
                HeaderText = "UOM"
            };

            var column4 = new DataGridViewTextBoxColumn
            {
                Name = "QuanityColumn",
                HeaderText = "Quanity"
            };

            ItemsDataGridView.Columns.AddRange(column1, column2, column3, column4);
            ItemsDataGridView.EditingControlShowing += DataGridView1OnEditingControlShowing;
        }

        private void DataGridView1OnEditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
        {
            if (!ItemsDataGridView.CurrentCell.IsComboBoxCell()) return;
            if (ItemsDataGridView.Columns[ItemsDataGridView.CurrentCell.ColumnIndex].Name != _comboColumnName) return;

            _cbo = e.Control as ComboBox;
            _cbo.SelectedIndexChanged -= ItemCodeColumnComboSelectionChanged;
            _cbo.SelectedIndexChanged += ItemCodeColumnComboSelectionChanged;
        }

        private void ItemCodeColumnComboSelectionChanged(object sender, EventArgs e)
        {
            DataGridViewComboBoxEditingControl control = sender as DataGridViewComboBoxEditingControl;
            Item item = _items.FirstOrDefault(x => x.ItemCode == control.EditingControlFormattedValue.ToString());
            if (item == null)
            {
                return;
            }
            ItemsDataGridView.CurrentRow.Cells[1].Value = item.Name;
            ItemsDataGridView.CurrentRow.Cells[2].Value = item.UOM;

        }
    }

    #region Place classes into their own files

    public static class Extensions
    {
        public static bool IsComboBoxCell(this DataGridViewCell sender)
            => sender.EditType != null && 
               sender.EditType == typeof(DataGridViewComboBoxEditingControl);
    }

    // represents a table in a database
    public class Item
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string ItemCode { get; set; }
        public string UOM { get; set; }
        public override string ToString() => ItemCode;
    }

    class Mocked
    {
        // simulate data from database
        public static List<Item> Items => new List<Item>()
        {
            new Item() {Id = 1,Name = "P1", ItemCode = "A100", UOM = "Q1"},
            new Item() {Id = 2,Name = "P2", ItemCode = "A200", UOM = "W1"},
            new Item() {Id = 3,Name = "P3", ItemCode = "A300", UOM = "B1"},
            new Item() {Id = 4,Name = "P4", ItemCode = "A400", UOM = "H1"}
        };
    }

    #endregion
}