somehow couldn't find this with a google search, but I feel like it has to be simple...I need to convert a string to a fixed-length byte array, e.g. write "asdf" to a byte[20] array. the data is being sent over the network to a c++ app that expects a fixed-length field, and it works fine if I use a BinaryWriter and write the characters one by one, and pad it by writing '\0' an appropriate number of times.
is there a more appropriate way to do this?
static byte[] StringToByteArray(string str, int length)
{
return Encoding.ASCII.GetBytes(str.PadRight(length, ' '));
}
length. If we have 50 bytes long string, and we use this method with length parameter 30, we got 50 bytes long byte array instead of 30.This is one way to do it:
string foo = "bar";
byte[] bytes = ASCIIEncoding.ASCII.GetBytes(foo);
Array.Resize(ref bytes, 20);
How about
String str = "hi";
Byte[] bytes = new Byte[20];
int len = str.Length > 20 ? 20 : str.Length;
Encoding.UTF8.GetBytes(str.Substring(0, len)).CopyTo(bytes, 0);
You can use Encoding.GetBytes.
byte[] byteArray = new byte[20];
Array.Copy(Encoding.ASCII.GetBytes(myString), byteArray, System.Math.Min(20, myString.Length);
With unsafe code perhaps?
unsafe static void Main() {
string s = "asdf";
byte[] buffer = new byte[20];
fixed(char* c = s)
fixed(byte* b = buffer) {
Encoding.Unicode.GetBytes(c, s.Length, b, buffer.Length);
}
}
(the bytes in the buffer will default to 0, but you can always zero them manually)
Byte[] bytes = new Byte[20];
String str = "blah";
System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
bytes = encoding.GetBytes(str);
bytes with a new array length of 4.And just for completeness, LINQ:
(str + new String(default(Char), 20)).Take(20).Select(ch => (byte)ch).ToArray();
For variation, this snippet also elects to cast the Unicode character directly to ASCII, since the first 127 Unicode characters are defined to match ASCII.
FieldOffset, maybe?
[StructLayout(LayoutKind.Explicit)]
public struct struct1
{
[FieldOffset(0)]
public byte a;
[FieldOffset(1)]
public int b;
[FieldOffset(5)]
public short c;
[FieldOffset(8)]
public byte[] buffer;
[FieldOffset(18)]
public byte d;
}
(c) http://www.developerfusion.com/article/84519/mastering-structs-in-c/
