How to create directories in C#

This method allows you to create directories at a specified path, whether it's an absolute or relative path.

1. Creating a Directory at a Specified Path

To begin, you can use Directory.CreateDirectory() to create a directory at a given path. This can be an absolute or relative path.

using System.IO;

Directory.CreateDirectory(@"C:\dell\dotnet\examples\");

In the above code, the directory examples will be created inside the C:\dell\dotnet\ folder. If any of the parent directories (such as dotnet or dell) do not exist, they will also be created automatically.

2. Directory.CreateDirectory() Handles Missing Directories in the Path

When you use Directory.CreateDirectory(), it does more than just create the specified directory. It also creates all the missing parent directories in the provided path.

For example, if you want to create the directory C:\test\data\, and neither the test nor the data directories exist, Directory.CreateDirectory() will create both the test and data directories automatically.

using System.IO;

Console.WriteLine("Before creating");
Console.WriteLine($@"C:\test\ exists? {Directory.Exists(@"C:\test\")}"); 
Console.WriteLine($@"C:\test\data\ exists? {Directory.Exists(@"C:\test\data\")}");

Directory.CreateDirectory(@"C:\test\data\");

Console.WriteLine("After creating");
Console.WriteLine($@"C:\test\ exists? {Directory.Exists(@"C:\test\")}"); 
Console.WriteLine($@"C:\test\data\ exists? {Directory.Exists(@"C:\test\data\")}"); 

3. Checking If a Directory Exists Before Creating It

Although Directory.CreateDirectory() will not throw an error if the directory already exists, you may sometimes want to check if a directory exists before creating it, especially if you want to log this action or perform additional tasks. To do this, you can use Directory.Exists() to check if the directory is already present before creating it.

using System.IO;

var dirPath = @"C:\data\";

if (!Directory.Exists(dirPath))
{
    Console.WriteLine("Directory doesn't exist. Will create it.");
    Directory.CreateDirectory(dirPath);
}

In this example, the code checks if the data directory exists, and if it doesn’t, it proceeds to create the directory.

4. Creating a Directory with a Relative Path

You don’t always need to use absolute paths when working with directories. Directory.CreateDirectory() can also accept relative paths. A relative path is based on the current working directory, which can be accessed using Environment.CurrentDirectory. This feature is helpful when you’re working within a project or a specific folder structure.

using System.IO;

var directoryInfo = Directory.CreateDirectory("data");
Console.WriteLine($"Created directory path: {directoryInfo.FullName}");
Console.WriteLine($"Current working directory: {Environment.CurrentDirectory}");

5. Using the DirectoryInfo Object Returned by CreateDirectory()

The Directory.CreateDirectory() method returns a DirectoryInfo object that provides additional information about the created directory. This DirectoryInfo object can be used to inspect properties of the directory and perform additional tasks, such as creating subdirectories.

using System.IO;

var dirInfo = Directory.CreateDirectory(@"C:\dell\projects\");

dirInfo.CreateSubdirectory("src");
dirInfo.CreateSubdirectory("tests");
dirInfo.CreateSubdirectory("data");

In this example, a projects directory is created at C:\dell\ along with three subdirectories: src, tests, and data. These subdirectories are created relative to the projects directory, and you can continue to organize your project in a clean directory structure.