System.IO.StreamWriter Class

Provides a convenient way to write text to a Stream in a particular encoding. The StreamWriter class implements TextWriter and adds methods for writing strings and characters to a stream.

When to use

Writing text files with specific encodings.
Appending to existing files.
Logging data to streams (e.g., network, memory).

Syntax

public sealed class StreamWriter : TextWriter
{
    // Constructors
    public StreamWriter(Stream stream);
    public StreamWriter(string path);
    public StreamWriter(string path, bool append);
    public StreamWriter(string path, bool append, Encoding encoding);
    public StreamWriter(string path, bool append, Encoding encoding, int bufferSize);

    // Properties
    public Encoding Encoding { get; }
    public bool AutoFlush { get; set; }
    public Stream BaseStream { get; }

    // Methods
    public override void Write(string value);
    public override void WriteLine(string value);
    public void Flush();
    public void Close();
}

Constructors

Signature	Description
`StreamWriter(Stream stream)`	Initializes a new instance for the specified stream using UTF-8 encoding.
`StreamWriter(string path)`	Creates a new file at the specified path.
`StreamWriter(string path, bool append)`	Creates a new file or appends to an existing file.
`StreamWriter(string path, bool append, Encoding encoding)`	Specifies encoding and append mode.
`StreamWriter(string path, bool append, Encoding encoding, int bufferSize)`	Specifies encoding, append mode, and buffer size.

Properties

Name	Type	Description
`Encoding`	`Encoding`	Gets the encoding used by the current writer.
`AutoFlush`	`bool`	Indicates whether the writer flushes its buffer after each write operation.
`BaseStream`	`Stream`	Gets the underlying stream.

Methods

Name	Signature	Description
`Write`	`void Write(string value)`	Writes a string to the stream.
`WriteLine`	`void WriteLine(string value)`	Writes a string followed by a line terminator.
`Flush`	`void Flush()`	Clears buffers and writes any buffered data to the underlying device.
`Close`	`void Close()`	Closes the current writer and the underlying stream.

Example

using System;
using System.IO;
using System.Text;

class Program
{
    static void Main()
    {
        string path = "sample.txt";

        // Write text to a file using UTF-8 encoding
        using (var writer = new StreamWriter(path, false, Encoding.UTF8))
        {
            writer.AutoFlush = true;
            writer.WriteLine("Hello, World!");
            writer.WriteLine($"Current Time: {DateTime.Now}");
        }

        // Read and display the file contents
        Console.WriteLine("File Contents:");
        using (var reader = new StreamReader(path, Encoding.UTF8))
        {
            Console.WriteLine(reader.ReadToEnd());
        }
    }
}