File.Copy(String, String, Boolean) Method in C# with Examples

File.Copy(String, String, Boolean) is an inbuilt File class method that is used to copy the content of the existing source file content to another destination file if exist, else create a new destination file then copying process is done.
Syntax:

public static void Copy (string sourceFileName, string destFileName, bool overwrite);

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

• sourceFileName: This is the file from where data is copied.
• destFileName: This is the file where data is pasted.
• overwrite: This is the boolean value. It uses true if the destination file can be overwritten otherwise it uses false.

Exceptions:

• UnauthorizedAccessException: The destFileName is read-only OR Here overwrite is true if the destFileName exists and is hidden, but source filename is not hidden.
• ArgumentException: The source filename or destFileName is a zero-length string, contains only white space, or contains one or more invalid characters as defined by InvalidPathChars. OR the sourceFileName or destFileName specifies a directory.
• ArgumentNullException: The sourceFileName or destFileName is null.
• PathTooLongException: The specified path, file name, or both exceed the system-defined maximum length.
• DirectoryNotFoundException: The path specified in source filename or destFileName is invalid (for example, it is on an unmapped drive).
• FileNotFoundException: The source filename was not found.
• IOException: The destFileName exists and overwrite is false OR An I/O error has occurred.
• NotSupportedException: The sourceFileName or destFileName is in an invalid format.

Below are the programs to illustrate the File.Copy(String, String, Boolean) method.
Program 1: Before running the below code, two files i.e, source file file.txt and destination file gfg.txt are created with some contents shown below:

C#

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

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

class GFG {
    // Main() method
    public static void Main()
    {
        // Specifying two files
        string sourceFile = @"file.txt";
        string destinationFile = @"gfg.txt";
        try {
            // Copying source file's contents to
            // destination file
            File.Copy(sourceFile, destinationFile, true);
        }
        catch (IOException iox) {
            Console.WriteLine(iox.Message);
        }
        Console.WriteLine("Copying process has been done.");
    }
}

Executing:

mcs -out:main.exe main.cs
mono main.exe
Copying process has been done.

After running the above code, above output is shown and the destination file contents become like shown below:

Program 2: Before running the below code, two files i.e, source file file.txt and destination file gfg.txt is created with some contents shown below:

C#

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

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

class GFG {
    // Main() method
    public static void Main()
    {
        // Specifying two files
        string sourceFile = @"file.txt";
        string destinationFile = @"gfg.txt";
        try {
            // Copying source file's contents to
            // destination file
            File.Copy(sourceFile, destinationFile, true);
        }
        catch (IOException iox) {
            Console.WriteLine(iox.Message);
        }
        Console.WriteLine("Copying process has been done.");
    }
}

Executing:

mcs -out:main.exe main.cs
mono main.exe
Copying process has been done.

After running the above code, above output is shown and the destination file contents get overwritten with the content of source file file.txt like shown below:

Program 3: Before running the below code, two files i.e, source file file.txt and destination file gfg.txt is created with some contents shown below:

C#

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

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

class GFG {
    // Main() method
    public static void Main()
    {
        // Specifying two files
        string sourceFile = @"file.txt";
        string destinationFile = @"gfg.txt";
        try {
            // Copying source file's contents to
            // destination file
            File.Copy(sourceFile, destinationFile, false);
        }
        catch (IOException iox) {
            Console.WriteLine(iox.Message);
        }
    }
}

Executing:

mcs -out:main.exe main.cs
mono main.exe
Could not create file "/home/runner/NutritiousHeavyRegression/gfg.txt". File already exists.

After running the above code, above error is thrown this is because the bool overwrite values used in the above code is false.