convert list of hex string to hex list - dart

Question

I would need to convert this list of Strings:
[00, 02, F0, 12, 04, 00, 00, 05, 03, 01]
into
[0x00, 0x02, 0xF0, 0x12, 0x04, 0x00, 0x00, 0x05, 0x03, 0x01]
How can I achieve this?

Answer 1

This function may help you:
toHex() method can convert unit8stringlist to hex list
toUnitList() method can convert hex list to unit8stringlist
static toHex(Uint8List bArr) {
int length;
if (bArr == null || (length = bArr.length) <= 0) {
return "";
}
Uint8List cArr = new Uint8List(length << 1);
int i = 0;
for (int i2 = 0; i2 < length; i2++) {
int i3 = i + 1;
var cArr2 = [
'0',
'1',
'2',
'3',
'4',
'5',
'6',
'7',
'8',
'9',
'A',
'B',
'C',
'D',
'E',
'F'
];
var index = (bArr[i2] >> 4) & 15;
cArr[i] = cArr2[index].codeUnitAt(0);
i = i3 + 1;
cArr[i3] = cArr2[bArr[i2] & 15].codeUnitAt(0);
}
return new String.fromCharCodes(cArr);
}
static hex(int c) {
if (c >= '0'.codeUnitAt(0) && c <= '9'.codeUnitAt(0)) {
return c - '0'.codeUnitAt(0);
}
if (c >= 'A'.codeUnitAt(0) && c <= 'F'.codeUnitAt(0)) {
return (c - 'A'.codeUnitAt(0)) + 10;
}
}
static toUnitList(String str) {
int length = str.length;
if (length % 2 != 0) {
str = "0" + str;
length++;
}
List<int> s = str.toUpperCase().codeUnits;
Uint8List bArr = Uint8List(length >> 1);
for (int i = 0; i < length; i += 2) {
bArr[i >> 1] = ((hex(s[i]) << 4) | hex(s[i + 1]));
}
return bArr;
}

Answer 2

I am confused about what you really want but here is an example of some operations you can do:
void main() {
// List of strings
final input = ['00', '02', 'F0', '12', '04', '00', '00', '05', '03', '01'];
// List of ints
final output = input.map((e) => int.parse(e, radix: 16)).toList();
// Print list of ints in radix 10
print(output); // [0, 2, 240, 18, 4, 0, 0, 5, 3, 1]
// Print list of ints as hex strings
print(output.map(toHexString).toList());
// [0x00, 0x02, 0xf0, 0x12, 0x04, 0x00, 0x00, 0x05, 0x03, 0x01]
}
String toHexString(int number) =>
'0x${number.toRadixString(16).padLeft(2, '0')}';
And if your strings are actually beginning with "0x" you can do this:
void main() {
// List of strings
final input = ['0x00', '0x02', '0xF0', '0x12', '0x04', '0x00', '0x00', '0x05', '0x03', '0x01'];
// List of ints
final output = input.map((e) => int.parse(e.replaceFirst('0x', ''), radix: 16)).toList();
// Print list of ints in radix 10
print(output); // [0, 2, 240, 18, 4, 0, 0, 5, 3, 1]
// Print list of ints as hex strings
print(output.map(toHexString).toList());
// [0x00, 0x02, 0xf0, 0x12, 0x04, 0x00, 0x00, 0x05, 0x03, 0x01]
}
String toHexString(int number) =>
'0x${number.toRadixString(16).padLeft(2, '0')}';