public static string Bcd2Ascii(byte[] packedBytes, ref int index, ISOFieldPadding padding, int valueLength)
{
var value = valueLength <= MaxStackAllocationSize
? stackalloc char[valueLength]
: new char[valueLength];
if (valueLength % 2 == 0)
{
// no padding needed just convert to bcd
for (int i = 0; i < valueLength; i += 2)
{
value[i] = (char)((packedBytes[index] >> 4) + 0x30);
value[i + 1] = (char)((packedBytes[index] & 0x0F) + 0x30);
index++;
}
}
else
{
if (padding == ISOFieldPadding.LEFT)
{
// LEFT padding so ignore the first half byte/ just read the second half byte
value[0] = (char)((packedBytes[index] & 0x0F) + 0x30);
index++;
for (int i = 1; i < valueLength; i += 2)
{
value[i] = (char)((packedBytes[index] >> 4) + 0x30);
value[i + 1] = (char)((packedBytes[index] & 0x0F) + 0x30);
index++;
}
}
if (padding == ISOFieldPadding.RIGHT)
{
// RIGHT padding so ignore the last half byte/ just read the first half of last byte
int i;
for (i = 0; i < valueLength - 1; i += 2)
{
value[i] = (char)((packedBytes[index] >> 4) + 0x30);
value[i + 1] = (char)((packedBytes[index] & 0x0F) + 0x30);
index++;
}
value[i] = (char)((packedBytes[index] >> 4) + 0x30);
}
}
return(value.ToString());
}
public static void Ascii2Bcd(string value, byte[] packedBytes, ref int index, ISOFieldPadding padding, byte paddingCharacter)
{
int valueLength = value.Length;
int startIndex = 0;
bool needPadding = valueLength % 2 != 0;
if (needPadding && padding == ISOFieldPadding.LEFT)
{
//Read data and take first nibble
if (paddingCharacter != 0)
{
//left nibble padding set to padding character and add the single nibble at the end
packedBytes[index] = (byte)((paddingCharacter << 4) + (value[0] - 0x30));
}
else
{
//left nibble padding leave empty and make a byte from the first nibble of the data
packedBytes[index] = (byte)(value[0] - 0x30);
}
index++;
//ignore the first char of the value, since we have already read it.
startIndex++;
}
else if (needPadding && padding == ISOFieldPadding.RIGHT)
{
//Stop before the last half nibble, in the loop
valueLength--;
}
// no padding needed just convert to bcd
for (int i = startIndex; i < valueLength; i += 2)
{
packedBytes[index] = (byte)(((value[i] - 0x30) << 4) + value[i + 1] - 0x30);
index++;
}
if (needPadding && padding == ISOFieldPadding.RIGHT)
{
//read the last remaining nibble in the value and pad the last byte
if (paddingCharacter != 0)
{
//right nibble padding, take the last nibble and set it as the high part of the byte, leave the low/right side as the padding character
packedBytes[index] = (byte)(((value[valueLength] - 0x30) << 4) + paddingCharacter);
}
else
{
//right nibble padding, take the last nibble and set it as the high part of the byte, leave the low/right side as 0
packedBytes[index] = (byte)((value[valueLength] - 0x30) << 4);
}
index++;
}
}
/// <summary>
/// Do not use
/// </summary>
/// <param name="value"></param>
/// <param name="packedBytes"></param>
/// <param name="index"></param>
/// <param name="padding"></param>
public static void Ascii2BcdOld(string value, byte[] packedBytes, ref int index, ISOFieldPadding padding)
{
int valueLength = value.Length;
if (valueLength % 2 == 0)
{
// no padding needed just convert to bcd
for (int i = 0; i < valueLength; i += 2)
{
packedBytes[index] = (byte)((value[i] - 0x30) * 0x10 + value[i + 1] - 0x30);
index++;
}
}
else
{
// one for end of string and one for padding char
string bcdString = string.Empty;
if (padding == ISOFieldPadding.LEFT)
{
bcdString = "0" + value;
}
else if (padding == ISOFieldPadding.RIGHT)
{
bcdString = value + "0";
}
valueLength = bcdString.Length;
for (int i = 0; i < valueLength; i += 2)
{
packedBytes[index] = (byte)((bcdString[i] - 0x30) * 0x10 + bcdString[i + 1] - 0x30);
index++;
}
}
}
public static void Ascii2Bcd(string value, byte[] packedBytes, ref int index, ISOFieldPadding padding)
{
int valueLength = value.Length;
int startIndex = 0;
bool needPadding = valueLength % 2 != 0;
if (needPadding && padding == ISOFieldPadding.LEFT)
{
//left nibble padding leave empty and make a byte from the first nibble of the data
packedBytes[index] = (byte)(value[0] - 0x30);
index++;
//ignore the first char of the value
startIndex++;
}
else if (needPadding && padding == ISOFieldPadding.RIGHT)
{
//Stop before the last half nibble
valueLength--;
}
// no padding needed just convert to bcd
for (int i = startIndex; i < valueLength; i += 2)
{
packedBytes[index] = (byte)((value[i] - 0x30) * 0x10 + value[i + 1] - 0x30);
index++;
}
if (needPadding && padding == ISOFieldPadding.RIGHT)
{
//right nibble padding, take the last nibble and set it as the high part of the byte, leave the low/right side as 0
packedBytes[index] = (byte)((value[valueLength] - 0x30) * 0x10);
index++;
}
}
