How can string be transferred to the List?

[rosemadder]

Like such a line:

"[ [ [1],[2],[3] ], [ [4],[5],[6]] ]"

Put the same kind on the list?

[magpie]

If the line is always in such a format, regular expression can be used. For example:

using System.Text.RegularExpressions;
// ...
var s = "[ [ [1],[2],[3] ], [ [4],[5],[6]] ]";
var lst = Regex.Matches(s, "\\d+").Cast<Match>().Select(m => m.Value).ToList();
Console.WriteLine(String.Join(";", lst));   // 1,2,3,4,5,6 

And if the line is different (and it appears to be JSON), then you should use JSON-Parser, for example. http://www.newtonsoft.com/json - is located in Microsoft Azure SDK (in the collection of Newtonsoft.Json.dll), it can also be downloaded as a separate package with https://www.nuget.org/packages/newtonsoft.json/ ♪