Question

给定Location的列表，我需要做两个订购步骤。

按LocationType升序排序。
对于每个位置类型值顺序，这些结果由Name升序。

示例数据：

Location Type | Name
            2 | Templestowe Lower
            2 | Templestowe
            1 | Melbourne

预期结果：

1. Melbourne
2. Templestowe
3. Templestowe Lower

Here is a (not working) .NET Fiddle ...

这里是主要代码（从那个小提琴复制而来）..

private class Location
{
    public Location (string name, int locationType)
    {
        Name = name;
        LocationType = locationType;
    }

    public string Name { get; private set; }
    public int LocationType { get; private set;}
}

public static void Main()
{

    var locations = new List<Location> 
    {
        new Location("Templestowe Lower", 2),
        new Location("Templestowe", 2),
        new Location("Melbourne", 1)
    };

    // TODO: return a list, sorted by LocationType and name.
    var results = XXXXX;

    foreach(var location in results)
    {
        Console.WriteLine(location.Name);
    }
}

Answer 1

locations.Sort((x,y) => {
   int delta = x.LocationType.CompareTo(y.LocationType);
   if(delta == 0) delta = string.Compare(x.Name, y.Name);
   return delta;
});

可替换地：

var results = locations.OrderBy(x => x.LocationType).ThenBy(x => x.Name);

或者在LINQ语法中（编译成同样的东西）：

var results = from loc in locations
              orderby loc.LocationType, loc.Name
              select loc;

Answer 2

使用分组

进行检查

var results = locations
            .GroupBy(x => x.LocationType)
            .OrderBy(x => x.Key)
            .SelectMany(g => g.OrderBy(x=>x.Name));

如何通过两个属性订购这个简单的.NET列表？

2 个答案: