File.Create(String, Int32) Method in C# with Examples

File.Create(String, Int32) is an inbuilt File class method which is used to overwrite an existing file, specifying a buffer size else create a new file if the specified file is not existing.
Syntax:

public static System.IO.FileStream Create (string path, int bufferSize);

Parameter: This function accepts two parameters which are illustrated below: 

• path: This is the specified file path.
• bufferSize: This is the specified buffer size.

Exceptions:

• UnauthorizedAccessException: The caller does not have the required permission. OR the path specified a file that is read-only. OR the path specified a file that is hidden.
• ArgumentException: The path is a zero-length string, contains only white space, or one or more invalid characters as defined by InvalidPathChars.
• ArgumentNullException: The path is null.
• PathTooLongException: The given path, file name, or both exceed the system-defined maximum length.
• DirectoryNotFoundException: The specified path is invalid (for example, it is on an unmapped drive).
• IOException: An I/O error occurred while creating the file.
• NotSupportedException: The path is in an invalid format.

Below are the programs to illustrate the File.Create(String, Int32) method.
Program 1: Initially, no file is created. Below code itself create a new file file.txt with the specified contents.

CSharp

// C# program to illustrate the usage
// of File.Create(String, Int32) method

// Using System, System.IO and
// System.Text namespaces
using System;
using System.IO;
using System.Text;

class GFG {
    public static void Main()
    {
        // Specifying a file path
        string file_path = @"file.txt";

        try {
            // Creating a new file with below
            // specified contents
            using(FileStream fs = File.Create(file_path, 1024))
            {
                // Adding some info into the file
                byte[] info = new UTF8Encoding(true).GetBytes("GeeksforGeeks");
                fs.Write(info, 0, info.Length);
            }

            // Reading the file contents
            using(StreamReader sr = File.OpenText(file_path))
            {
                string s = "";
                while ((s = sr.ReadLine()) != null) {
                    Console.WriteLine(s);
                }
            }
        }
        catch (Exception ex) {
            Console.WriteLine(ex.ToString());
        }
    }
}

Executing:

mcs -out:main.exe main.cs
mono main.exe
GeeksforGeeks

After running the above code, above output is shown and a new file file.txt is created with some specified contents shown below:

Program 2: The below shown file file.txt is created before running the below code. 

CSharp

// C# program to illustrate the usage
// of File.Create(String) method

// Using System, System.IO and
// System.Text namespaces
using System;
using System.IO;
using System.Text;

class GFG {
    public static void Main()
    {
        // Specifying a file path
        string file_path = @"file.txt";

        try {
            // Overwriting the above file contents
            using(FileStream fs = File.Create(file_path, 1024))
            {
                // Adding some info into the file
                byte[] info = new UTF8Encoding(true).GetBytes("GFG is a CS Portal");
                fs.Write(info, 0, info.Length);
            }

            // Reading the file contents
            using(StreamReader sr = File.OpenText(file_path))
            {
                string s = "";
                while ((s = sr.ReadLine()) != null) {
                    Console.WriteLine(s);
                }
            }
        }

        catch (Exception ex) {
            Console.WriteLine(ex.ToString());
        }
    }
}

Executing:

mcs -out:main.exe main.cs
mono main.exe
GFG is a CS Portal

After running the above code, the above output is shown, and existing file contents get overwritten.