返回对象数组的不同列表，其中数组项的数量是非特定的

有没有办法使用LINQ从对象数组列表中获取不同的项目列表，而不知道每个数组中有多少项？ 每个数组项中的项数在整个列表中都是相同的。

// Foo is a list of object arrays. The number of items // each array is non-specific. // (In this example there is only 3 items, but there could be 100) var foo = new List(); // I add some items to the list. foo.Add(new object[] { 1, "Something", true }); foo.Add(new object[] { 1, "Some Other", false }); foo.Add(new object[] { 2, "Something", false }); foo.Add(new object[] { 2, "Something", false }); // This will get me a distinct list from the array list... // but it requires I know how many items are in each array. List bar = foo.Select(x => new { X1 = x[0], X2 = x[1], X3 = x[2] }) .Distinct() .Select(x => new object[] { x.X1, x.X2, x.X3 }) .ToList(); List bar = ?? /// < -- How can I rewrite the // previous line so that // my code works with n array items? 

如果有帮助，我会知道运行时有多少项？

如果在LINQ中不可能，那么有人可以建议我可以用来实现预期结果的方法吗？

Answer 1

如果我理解你，你可以尝试这样的事情：

  class Comparer : IEqualityComparer { public bool Equals(object[] x, object[] y) { if (x.Length != y.Length) return false; for (int i = 0; i < x.Length; ++i) if (!x[i].Equals(y[i])) return false; return true; } public int GetHashCode(object[] obj) { return string.Join("", obj).GetHashCode(); } } static void Main(string[] args) { var foo = new List(); foo.Add(new object[] { 1, "Something", true }); foo.Add(new object[] { 1, "Some Other", false }); foo.Add(new object[] { 2, "Something", false }); foo.Add(new object[] { 2, "Something", false }); var distinctList = foo.Distinct(new Comparer()).ToList(); /* distinctList now contains 1, "Something", true 1, "Some Other", false 2, "Something", false */ } 

Answer 2

请尝试使用以下代码

 List bar = foo.GroupBy(x => new { X1 = x[0], X2 = x[1], X3 = x[2] }).Select(g => new object[] { g.Key.X1, g.Key.X2, g.Key.X3, g.Count() }).ToList(); 

每个对象有四个值，最后一个用于组计数