Question

我目前正在使用MVC搜索并返回3个不同数据库的结果。每个数据库的结果放在一组SoftwareLight个对象中，这些对象包含来自所有数据库的公共字段，以及一个Context属性，用于指示结果来自哪个数据库。那部分到目前为止效果很好。

现在我要做的是将具有相同名称但来自不同上下文的每个SoftwareLight对象组合到一个条目中。理想情况下，这个＆＃34;的Context属性合并了＃34;条目也将保留所有发现的背景......

为了举例说明这些结果集的外观，以及我最终要达到的目标，请参阅下文。但主要是，我的问题如下：

如何让Context属性一次接受多个枚举条目？（我已经看到使用单个&或单个|完成此操作，之后使用Enum.HasFlag();方法进行了检查？）
如何有效地将具有相同名称的结果合并/合并到一个条目中？

[编辑]根据要求，我添加了SoftwareLight类和Context枚举声明。

 public class SoftwareLight : IEquatable<SoftwareLight>
 {
    public string Name { get; set; }
    public string Version { get; set; }
    public int? Installs { get; set; }
    public AppContext Context { get; set; }
    public bool External { get; set; }
 }

[Flags]
public enum AppContext
{
    NET,
    LOCAL,
    LICENSES
}

当前搜索代码的示例：

        //Current searching method...
        NET_DATA db1 = new Model.NET_DATA();
        LOCAL_DATA db2 = new Model.LOCAL_DATA();
        LICENSING_DATA db3 = new Model.LICENSING_DATA();

        List<SoftwareLight> finds = new List<SoftwareLight>();

        //SoftwareLight items returned have their Context Property set to 'NET'
        finds.AddRange(db1.Find(searchterms));
        //SoftwareLight items returned have their Context Property set to 'LOCAL'
        finds.AddRange(db2.Find(searchterms));
        //SoftwareLight items returned have their Context Property set to 'LICENSES'
        finds.AddRange(db3.Find(searchterms));

        finds = finds.OrderBy(a => a.Name).ToList();

        //HOW DO I COMBINE THEM HERE?

当前结果的示例，搜索术语＆＃34; Dreamweaver＆＃34;：

    |---------------------------------------------------------|
    | Product Name      | Context  | Public Facing | Installs |
    |---------------------------------------------------------|
    | Adobe Dreamweaver | NET      | No            | 23       |
    |---------------------------------------------------------|
    | Adobe Dreamweaver | LOCAL    | No            | 7        |
    |---------------------------------------------------------|
    | Adobe Dreamweaver | LICENSES | No            | 9        |
    |---------------------------------------------------------|

想要结果的示例，搜索术语Dreamweaver：

    |---------------------------------------------------------------------|
    | Product Name      | Context              | Public Facing | Installs |
    |---------------------------------------------------------------------|
    | Adobe Dreamweaver | NET, LOCAL, LICENSES | No            | 39       |
    |---------------------------------------------------------------------|

Answer 1

您似乎需要GroupBy而不是OrderBy。

所以不要做

finds = finds.OrderBy(a => a.Name).ToList();

你应该这样做：

var myGroups = finds
   .GroupBy(a => a.Name)
   .Select(g => new SoftwareLight() {
        Name = g.Key,
        // What should be done with the version field?
        // Right now, I am concatenating distinct versions.
        Version = string.Join(", ", g.Select(v => v.Version).Distinct()),
        // "OR" through aggregation.
        Context = g.Aggregate((AppContext)0, (c, v) => (AppContext)(c | v.Context)),
        // True if any is public facing
        External = g.Any(v => v.External),
        Installs = g.Sum(v => v.Installs))
    });

Answer 2

由于标志只是整数，因此您可以在组子句中轻松总结它们。

假设您的上下文如下所示：

[Flags]
public enum Context
{
    NET = 1,
    LOCAL = 2,
    LICENSES = 4
}

public class Product
{
    public Context Context;
    public string Name;
}

Product[] items = new[]
{
    new Product { Name = "Adobe", Context = Context.NET },
    new Product { Name = "Adobe", Context = Context.LICENSES },
    new Product { Name = "Adobe", Context = Context.LOCAL },
    new Product { Name = "Adobe2", Context = Context.LOCAL },
    new Product { Name = "Adobe2", Context = Context.NET }
};

您可以使用此语句实际获取组合枚举：

var result = from item in items
    group item by item.Name
    into itemGroup
    select new
    {
        itemGroup.Key,
        Context = (Context)itemGroup.Sum(x => (int)x.Context)
    };

使用枚举连接列表中的对象

2 个答案: