I have string
w0 = "2B7E1516"
I want to convert it to a binary string in order to be
"00101011011111100001010100010110"
However i keep getting only "101011011111100001010100010110":
w0 = "2B7E1516";
char paddingChar = '0';
w0 = Convert.ToString(Convert.ToInt32(w0, 16), 2).PadLeft(8, paddingChar);
The problem is in 2 it converts it to only "10" not to "0010", how can i fix that?
Your output string is a 32 bit number, so the last line should be:
wo = Convert.ToString(Convert.ToInt32(w0, 16), 2).PadLeft(32, '0');
You only made it pad left 8 characters. If the resulting strings is more than 9 characters, it won't add more 0s to the left.
You should instead pad left by a multiple of 4. Which multiple of 4? That depends on the length of the hex string. Specifically, you should pad left by w0.Length * 4:
w0 = Convert.ToString(Convert.ToInt32(w0, 16), 2).PadLeft(w0.Length * 4, paddingChar);
Let's convert each char within the string with padding to 4 digits:
'0' -> "0" -> "0000"
'1' -> "1" -> "0001"
'2' -> "10" -> "0010"
...
'F' -> "1111" -> "FFFF"
Code:
string w0 = "2B7E1516";
// Since we convert string char by char the initial string can be arbitrary long
string result = string.Concat(w0.Select(c =>
('0' <= c && c <= '9' ? Convert.ToString(c - '0', 2) :
'a' <= c && c <= 'f' ? Convert.ToString(c - 'a' + 10, 2) :
Convert.ToString(c - 'A' + 10, 2)).PadLeft(4, '0')));