从对象集合列表中获取属性值

Question

我想使用对象集合的属性之一从对象集合中获取值属性。

使用Linq什么是SupplierSettingsList上的查询

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

您在寻找以下东西吗

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

Answer 2

它可以写成

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

您还可以在C: drive C:\\Program Files\\Microsoft Visual Studio 9.0\\Samples\\1033中找到该LINQ Query samples ，该CSharpSamples.zip解压缩并生成位于LinqSamples文件夹中的项目。

Answer 3

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

Answer 4

这是您要执行的操作：

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

我对您的SupplierSettings有点怀疑，因为这似乎不是OOP的很好例子。 最好考虑一下对象设计，而不是解决此查询。 只是一个建议。