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 对 SupplierSettingsList 进行查询

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

它可以写为“

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

您也可以在 C: 驱动器 中找到 LINQ 查询示例”
C:\Program Files\Microsoft Visual Studio 9.0\Samples\1033
在 CSharpSamples.zip 中解压缩并构建项目，位于文件夹 LinqSamples 中

Answer 2

您在寻找以下内容吗

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

Answer 3

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

Answer 4

这就是您想要做的吗：

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

我对您的 SupplierSettings 有点怀疑，因为它似乎不是一个很好的 OOP 示例。您最好考虑对象设计而不是计算此查询。只是一个建议。