從對象集合列表中獲取屬性值

Question

我想使用對象集合的屬性之一從對象集合中獲取值屬性。

使用Linq什么是SupplierSettingsList上的查詢

public class SupplierSettings
{
    private string Key;
    private SupplierSettingsPropertyEnum property;
    private string Value;
}

List<SupplierSettings> SupplierSettingsList =new List<SupplierSettingsDto>();

SupplierSettingsList .Add
(new SupplierSettings{Key="1",property=SupplierSettingsPropertyEnum.Name,Value="Name"});

SupplierSettingsList .Add
(new SupplierSettings{Key="2",property=SupplierSettingsPropertyEnum.StartTime,Value="7PM"});

SupplierSettingsList .Add
(new SupplierSettings{Key="3",property=SupplierSettingsPropertyEnum.EndTime,Value="10PM"});

SupplierSettingsList .Add
(new SupplierSettings{Key="4",property=SupplierSettingsPropertyEnum.Interval,Value="45"});

Answer 1

您在尋找以下東西嗎

var SupplierSettingsVales = SupplierSettings.
Where(x=>x.property==SupplierSettingsPropertyEnum.Interval)
    .Select(x=>x.Value);

Answer 2

它可以寫成

var results = from o in SupplierSettingsList
              where o.property == SupplierSettingsPropertyEnum.Interval
              select o.Value;

您還可以在C: drive C:\\Program Files\\Microsoft Visual Studio 9.0\\Samples\\1033中找到該LINQ Query samples ，該CSharpSamples.zip解壓縮並生成位於LinqSamples文件夾中的項目。

Answer 3

var value = SupplierSettings
  .Where(x=>x.property==SupplierSettingsPropertyEnum.Interval)
  .Select(x=>x.Value);
  .FirstOrDefault();

Answer 4

這是您要執行的操作：

var query =
    from ss in SupplierSettingsList
    where ss.property == SupplierSettingsPropertyEnum.Interval
    select ss.Value;

我對您的SupplierSettings有點懷疑，因為這似乎不是OOP的很好例子。 最好考慮一下對象設計，而不是解決此查詢。 只是一個建議。