有没有什么方法可以制作一个包含许多元素的C＃List？

Question

Any way to make a C# List with a given number of elements all at once? Not just add one by one, or copied from other IEnumerable. Then I can use indexers to assign values. I found a constructor List(int capacity) . Does it help?

Answer 1

Well, you can put it like this

 var List<MyType> result = Enumerable
   .Range(0, count)
   .Select(index => create your type instance here)
   .ToList();

and you may, probably, don't want additional steps (since you can fill the list via Select ). If you're looking for performance then

 // new List<MyType>(count) reserves memory for "count" items 
 // so "Add" will not reallocate the list
 var List<MyType> result = new List<MyType>(count);

 for (int i = 0; i < count; ++i) 
   result.Add(create your type instance here);