Cannot implicitly convert type 'System.Collect

问题:

I have the code below:

List<string> aa = (from char c in source
                   select new { Data = c.ToString() }).ToList();

But what about

List<string> aa = (from char c1 in source
                   from char c2 in source
                   select new { Data = string.Concat(c1, ".", c2)).ToList<string>();

While compile getting error

Cannot implicitly convert type 'System.Collections.Generic.List<AnonymousType#1>' to 'System.Collections.Generic.List<string>'

Need help.

回答1:

IEnumerable<string> e = (from char c in source
                        select new { Data = c.ToString() }).Select(t = > t.Data);
// or
IEnumerable<string> e = from char c in source
                        select c.ToString();
// or
IEnumerable<string> e = source.Select(c = > c.ToString());

---

Then you can call ToList():

List<string> l = (from char c in source
                  select new { Data = c.ToString() }).Select(t = > t.Data).ToList();
// or
List<string> l = (from char c in source
                  select c.ToString()).ToList();
// or
List<string> l = source.Select(c = > c.ToString()).ToList();

回答2:

If you want it to be List<string>, get rid of the anonymous type and add a .ToList() call:

List<string> list = (from char c in source
                     select c.ToString()).ToList();

回答3:

try

var lst= (from char c in source select c.ToString()).ToList();

回答4:

If you have source as a string like "abcd" and want to produce a list like this:

{ "a.a" },
{ "b.b" },
{ "c.c" },
{ "d.d" }

then call:

List<string> list = source.Select(c => String.Concat(c, ".", c)).ToList();

回答5:

I think the answers are below

List<string> aa = (from char c in source
                    select c.ToString() ).ToList();

List<string> aa2 = (from char c1 in source
                    from char c2 in source
                    select string.Concat(c1, ".", c2)).ToList();