print string to a byte pointer in c#

Question

I'm tring to translate C code to C# and I stumbled upon a line of code which I'm having problems translating.

sprintf((char*)&u8FirmareBuffer[0x1C0] + strlen((char*)&u8FirmareBuffer[0x1C0]), ".B%s", argv[3]);

specifically this line. u8FirmwareBuffer is a unsigned char array in C, a byte array in C# I would guess. argv[3] is a string. How can I translate this line to C#.

Thank you for your help.

Edit: This has been marked as a duplicate, but I think they differenciate because I am using pointers which don't work with the solutions presented on the marked post.

Answer 1

You could do something like:

string myString = "This is my string";
byte[] buffer = new byte[1024];
int offset = 0;

    // if you pass a byte buffer to the constructor of a memorystream, it will use that, don't forget that it cannot grow the buffer.
using (var memStream = new MemoryStream(buffer))
{
    // you can even seek to a specific position
    memStream.Seek(offset, SeekOrigin.Begin);

    // check your encoding..
    var data = Encoding.UTF8.GetBytes(myString);

    // write it on the current offset in the memory stream
    memStream.Write(data, 0, data.Length);
}

---

It's also possible with a StreamWriter

string myString = "This is my string";
byte[] buffer = new byte[1024];
int offset = 0;

// if you pass a byte buffer to the constructor.....(see above)
using (var memStream = new MemoryStream(buffer))
using (var streamWriter = new StreamWriter(memStream))
{
    // you can even seek to a specific position
    memStream.Seek(offset, SeekOrigin.Begin);

    streamWriter.Write(myString);
    streamWriter.Flush();

    // don't forget to flush before you seek again
}