Question

我有一个看起来像分组的对象

Dictionary<(ushort id, ushort sc), Timepoint[]> timepoints

它看起来像（1，2）=> [一些字符串时间点]

但是我想将其转换为

Dictionary<ushort id, Timepoint[]>

，我想聚合该sc并仅包含ID。我尝试过：

test = timepoints.GroupBy(group => group.Key.id).ToDictionary(key => key.Key, value => value);

但是我没有所有的运气。

Dictionary<ushort, IGrouping<ushort, KeyValuePair<(ushort id, ushort sc), Timepoint[]>>>

我想我缺少什么。

Answer 1

您需要使用SelectMany来整理要分组在一起的阵列，然后将它们首先转换为一个阵列。

var test = timepoints
    .GroupBy(kvp => kvp.Key.id)
    .Select(grp => new { grp.Key, Values = grp.SelectMany(x => x.Value).ToArray() })
    .ToDictionary(x => x.Key, x => x.Values);

Answer 2

@juharr答案的扩展和测试版本；

timepoints
    .GroupBy(kvp => kvp.Key.id)
    .Select(grp => new { grp.Key, Values = grp.SelectMany(x => x.Value).ToArray() })
    .ToDictionary(x => x.Key, x => x.Values);

这是您可以试用的整个测试控制台应用程序：

static void Main(string[] args)
{
    Dictionary<(ushort id, ushort sc), Timepoint[]> timepoints = new Dictionary<(ushort id, ushort sc), Timepoint[]>();
    timepoints.Add((1, 1), new Timepoint[] { new Timepoint(1, "1,1,1"), new Timepoint(1, "1,1,2"), new Timepoint(1, "1,1,3") });
    timepoints.Add((1, 2), new Timepoint[] { new Timepoint(1, "1,2,1"), new Timepoint(1, "1,2,2"), new Timepoint(1, "1,2,3") });
    timepoints.Add((2, 1), new Timepoint[] { new Timepoint(1, "2,1,1"), new Timepoint(1, "2,1,2"), new Timepoint(1, "2,1,3") });
    timepoints.Add((2, 2), new Timepoint[] { new Timepoint(1, "2,2,1"), new Timepoint(1, "2,2,2"), new Timepoint(1, "2,2,3") });
    var test = timepoints
                .GroupBy(kvp => kvp.Key.id)
                .Select(grp => new { grp.Key, Values = grp.SelectMany(x => x.Value).ToArray() })
                .ToDictionary(x => x.Key, x => x.Values);
}

class Timepoint
{
    public Timepoint(int id, string name)
    {
        this.Id = id;
        this.Name = name;
    }
    public int Id { get; set; }
    public string Name { get; set; }
}

使用C＃汇总分组

2 个答案: