在开始在C＃中循环之前将项目添加到集合中

Question

How do I dynamically add another path before looping to Directory.GetDirectories? :

foreach (string d in Directory.GetDirectories(dirpath))
{
    foreach (string f in Directory.GetFiles(d))
    {
        Console.WriteLine(f);
        File.Copy(f,"");
    }

}

For example I need it like

foreach (Directory dir in Directory.GetDirectories(dirpath).Add("another path"))
{ 
//My other code here.... 
}

How to do it?

Thanks

Answer 1

Maybe something like this:

Directory.GetDirectories(dirpath).Concat(new string[] { "another path"});

You need to add using System.Linq; at the top of your class.

Side Note on your expected result:

You can't foreach (Directory dir because Directory is a static class and you can't have an instance of it. But you can use DirectoryInfo :

var dirs = Directory.GetDirectories(dirpath)
                    .Concat(new string[] { "another path" })
                    .Select(path => new DirectoryInfo(path));

foreach (DirectoryInfo dir in dirs)
{

}

Answer 2

var dir = Directory.GetDirectories(dirpath);
dir.Add("another path");
foreach (string d in dir)
 {
     foreach (string f in Directory.GetFiles(d))
     {
        Console.WriteLine(f);
        File.Copy(f,"");
     }
 }

Answer 3

For achieving such a goal you may use a recursive approach like:

  public void Fileprocessing(directories){
             foreach (string d in directories)
                            {
                foreach (string f in Directory.GetFiles(d))
                                    {
                                    Console.WriteLine(f);
                                        File.Copy(f,"");
                                    }
            }
                if(conditionToAddPath){
                directories.Add("another path");
                Fileprocessing(directories);
                }
    }

and when you call the first time initialize your directories like:

...

string[] directories = Directory.GetDirectories(dirpath);
Fileprocessing(directories);

...

Note: this is a pseudo-coded answer!! please review before implementing or complete this answer by adding ready to use implementation code.

Answer 4

one way using SelectMany :

var paths = new List<string> { "path1", "path2", "path3" };
var files = paths.SelectMany(Directory.GetDirectories).SelectMany(Directory.GetFiles);
paths.Add("path4");

foreach (var file in files)
    Console.WriteLine(file);

another way using select :

var paths = new List<string> { "path1", "path2", "path3" };
var query = from path in paths
            from dir in Directory.GetDirectories(path)
            from file in Directory.GetFiles(dir)
            select file;
paths.Add("path4");

foreach (var file in query)
    Console.WriteLine(file);