使用pivot填充嵌套对象的Linq

var data = new List<Person>
{
    new Person { Name = "Alice", Category = "A", Value = 10 },
    new Person { Name = "Bob", Category = "B", Value = 20 },
    new Person { Name = "Alice", Category = "B", Value = 30 },
    new Person { Name = "Bob", Category = "A", Value = 40 },
};

var pivotData = data
    .GroupBy(p => p.Name)
    .Select(g => new
    {
        Name = g.Key,
        CategoryA = g.FirstOrDefault(p => p.Category == "A")?.Value,
        CategoryB = g.FirstOrDefault(p => p.Category == "B")?.Value
    })
    .ToList();

foreach (var item in pivotData)
{
    Console.WriteLine($"Name: {item.Name}, CategoryA: {item.CategoryA}, CategoryB: {item.CategoryB}");
}