C# BinaryWriter Class: Write Binary Data

In this tutorial, we'll demonstrate how to use the BinaryWriter class in C# to write binary data to a file. The BinaryWriter class is part of the System.IO namespace and provides methods for writing binary data to a stream.

Set up the environment

Create a new C# Console Application project in Visual Studio and add the following namespaces:

using System.IO;
using System.Text;

Write binary data to a file

To write binary data to a file, use the BinaryWriter class. The following code writes a string, an integer, a double, and a boolean to a binary file named data.bin:

using (FileStream fs = new FileStream("data.bin", FileMode.Create))
{
    using (BinaryWriter bw = new BinaryWriter(fs, Encoding.UTF8))
    {
        bw.Write("Hello, BinaryWriter!");
        bw.Write(42);
        bw.Write(3.14);
        bw.Write(true);
    }
}

In the example above, we first create a FileStream with the file mode set to Create, which creates a new file or overwrites an existing one. Then, we create a BinaryWriter instance, passing the file stream and encoding as parameters.

We use the Write method of the BinaryWriter class to write various data types to the binary file.

Read the binary data from the file

To verify that the binary data was written correctly, you can use the BinaryReader class to read the data from the data.bin file:

using (FileStream fs = new FileStream("data.bin", FileMode.Open))
{
    using (BinaryReader br = new BinaryReader(fs, Encoding.UTF8))
    {
        string text = br.ReadString();
        int number = br.ReadInt32();
        double value = br.ReadDouble();
        bool flag = br.ReadBoolean();

        Console.WriteLine($"Text: {text}");
        Console.WriteLine($"Number: {number}");
        Console.WriteLine($"Value: {value}");
        Console.WriteLine($"Flag: {flag}");
    }
}

When you run the Console Application, you should see the following output:

Text: Hello, BinaryWriter!
Number: 42
Value: 3.14
Flag: True

In this tutorial, we've shown you how to use the BinaryWriter class in C# to write binary data to a file. The BinaryWriter class provides methods for writing binary data to a stream, making it easy to write different data types to binary files.

C# BinaryWriter example:

Description: This example introduces the BinaryWriter class in C#, which provides methods for writing binary data to streams.

Code:

using (FileStream fileStream = new FileStream("binaryfile.bin", FileMode.Create))
using (BinaryWriter binaryWriter = new BinaryWriter(fileStream))
{
    // Write binary data using BinaryWriter methods
    binaryWriter.Write(42);
    binaryWriter.Write(3.14);
    // ... continue writing as needed
}

Seeking and navigating in binary files with BinaryWriter C#:

Description: Explaining how to use the Seek method of BinaryWriter to navigate to a specific position in a binary file.

Code:

using (FileStream fileStream = new FileStream("binaryfile.bin", FileMode.Create))
using (BinaryWriter binaryWriter = new BinaryWriter(fileStream))
{
    // Seek to a specific position in the file
    binaryWriter.Seek(8, SeekOrigin.Begin);

    // Write data to the new position
    binaryWriter.Write(42);
}