从 ListBox 获取完整信息

Question

我的主数组如下所示：

String[] main = new String[products.Count];

for (int i = 0; i < main.Length; i++)
{
    main[i] = products[i].id + 
              products[i].productowner + 
              products[i].description + 
              products[i].countryofmanufacture;
}

还有一个只有少数 products[i].productowner 值的字符串列表：

List<string> specificproductowners  = new List<string>();

我想知道通过单击 John 是否可以从主数组中获取所有其他信息（id、描述、ountryofmanufacture）

         A Windows Form listBox (specificproductowners)
         -----------------------------
         |        John               |            
         |        Alex               |
         |        Tom                |
         |        Jan                |
         -----------------------------

Answer 1

当你想要查询 collection 时，试试 Linq，像这样：

List<string> specificproductowners = products
  .Select(product => product.productowner)
  .Distinct()
  // .OrderBy(owner => owner) // Uncomment, if you want to sort 
  .ToList();  

如果您想将所有者添加到 ListBox：

MyListBox.Items.AddRange(products
  .Select(product => product.productowner)
  .Distinct()
  // .OrderBy(owner => owner) // Uncomment, if you want to sort
  .ToArray());             // AddRange wants an array

编辑：如果你想获得products中被productowner过滤的所有项目，你可以使用另一个Linq：

string owner = "Alex";

List<string> filtered = products
  .Where(product => product.productowner == owner) // "Alex" only
  .Select(product => string.Join(", ",  // let's combine into "id, description, country"
     product.id, 
     product.description,
     product.countryofmanufacture))
  .ToList();

 ...
 MessageBox.Show(
     string.Join(Environment.NewLine, filtered), 
   $"Test filtered for product owner \"{owner}\"");