我喜欢元组。它们允许您快速地将相关信息分组在一起，而不必为此编写结构或类。这在重构非常本地化的代码时非常有用。
然而，初始化它们的列表似乎有点多余。
var tupleList = new List<Tuple<int, string>>
{
Tuple.Create( 1, "cow" ),
Tuple.Create( 5, "chickens" ),
Tuple.Create( 1, "airplane" )
};
难道没有更好的办法吗?我希望有一个类似Dictionary初始化式的解决方案。
Dictionary<int, string> students = new Dictionary<int, string>()
{
{ 111, "bleh" },
{ 112, "bloeh" },
{ 113, "blah" }
};
我们不能使用类似的语法吗?
当前回答
老问题了，但这是我通常做的事情，让事情更具可读性:
Func<int, string, Tuple<int, string>> tc = Tuple.Create;
var tupleList = new List<Tuple<int, string>>
{
tc( 1, "cow" ),
tc( 5, "chickens" ),
tc( 1, "airplane" )
};
其他回答
超级老我知道，但我会在使用Linq和使用c# 7的方法上添加我的部分。在类中重用时，我尝试使用命名元组替换dto和匿名投影。是的，对于模拟和测试，你仍然需要类，但是内联做事情和在类中传递是很好的，有这个更新的选项。您可以实例化它们
直接实例化
var items = new List<(int Id, string Name)> { (1, "Me"), (2, "You")};
现在您可以返回类型良好的元组，类似于匿名投影的方式。
public class Hold
{
public int Id { get; set; }
public string Name { get; set; }
}
//In some method or main console app:
var holds = new List<Hold> { new Hold { Id = 1, Name = "Me" }, new Hold { Id = 2, Name = "You" } };
var anonymousProjections = holds.Select(x => new { SomeNewId = x.Id, SomeNewName = x.Name });
var namedTuples = holds.Select(x => (TupleId: x.Id, TupleName: x.Name));
稍后使用分组方法重用这些元组，或者使用其他逻辑中的方法内联构造它们:
//Assuming holder class above making 'holds' object
public (int Id, string Name) ReturnNamedTuple(int id, string name) => (id, name);
public static List<(int Id, string Name)> ReturnNamedTuplesFromHolder(List<Hold> holds) => holds.Select(x => (x.Id, x.Name)).ToList();
public static void DoSomethingWithNamedTuplesInput(List<(int id, string name)> inputs) => inputs.ForEach(x => Console.WriteLine($"Doing work with {x.id} for {x.name}"));
var namedTuples2 = holds.Select(x => ReturnNamedTuple(x.Id, x.Name));
var namedTuples3 = ReturnNamedTuplesFromHolder(holds);
DoSomethingWithNamedTuplesInput(namedTuples.ToList());
var colors = new[]
{
new { value = Color.White, name = "White" },
new { value = Color.Silver, name = "Silver" },
new { value = Color.Gray, name = "Gray" },
new { value = Color.Black, name = "Black" },
new { value = Color.Red, name = "Red" },
new { value = Color.Maroon, name = "Maroon" },
new { value = Color.Yellow, name = "Yellow" },
new { value = Color.Olive, name = "Olive" },
new { value = Color.Lime, name = "Lime" },
new { value = Color.Green, name = "Green" },
new { value = Color.Aqua, name = "Aqua" },
new { value = Color.Teal, name = "Teal" },
new { value = Color.Blue, name = "Blue" },
new { value = Color.Navy, name = "Navy" },
new { value = Color.Pink, name = "Pink" },
new { value = Color.Fuchsia, name = "Fuchsia" },
new { value = Color.Purple, name = "Purple" }
};
foreach (var color in colors)
{
stackLayout.Children.Add(
new Label
{
Text = color.name,
TextColor = color.value,
});
FontSize = Device.GetNamedSize(NamedSize.Large, typeof(Label))
}
this is a Tuple<Color, string>
是的!这是可能的。
集合初始化式的{}语法适用于任何IEnumerable 类型，它有一个添加方法，参数数量正确。 不用担心在被窝里是怎么工作的，这意味着你可以 简单地从List<T>扩展，添加一个自定义的add方法来初始化您的 T，你完成了!
public class TupleList<T1, T2> : List<Tuple<T1, T2>>
{
public void Add( T1 item, T2 item2 )
{
Add( new Tuple<T1, T2>( item, item2 ) );
}
}
这允许你做以下事情:
var groceryList = new TupleList<int, string>
{
{ 1, "kiwi" },
{ 5, "apples" },
{ 3, "potatoes" },
{ 1, "tomato" }
};
我认为有一个技巧比较简单，但之前没有提到过:
var asdf = new [] {
(Age: 1, Name: "cow"),
(Age: 2, Name: "bird")
}.ToList();
我认为这比:
var asdf = new List<Tuple<int, string>> {
(Age: 1, Name: "cow"),
(Age: 2, Name: "bird")
};
老问题了，但这是我通常做的事情，让事情更具可读性:
Func<int, string, Tuple<int, string>> tc = Tuple.Create;
var tupleList = new List<Tuple<int, string>>
{
tc( 1, "cow" ),
tc( 5, "chickens" ),
tc( 1, "airplane" )
};
