在android系统中，我正在尝试开发一个需要使用热敏打印机（NGX）打印QR码的应用程序。我认为，它无法正确解码，因此我无法解决此问题。
*** Details of Thermal printer
And i am getting output just like this.
QR打印方法
private void printQRCode() {
int QRCODE_IMAGE_HEIGHT = 255;
int QRCODE_IMAGE_WIDTH = 255;
String finalQR = "";
QRCodeWriter qrWriter = new QRCodeWriter();
try {
Hashtable<EncodeHintType, ErrorCorrectionLevel> hints = new Hashtable<EncodeHintType, ErrorCorrectionLevel>();
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
BitMatrix bitMatrix = qrWriter.encode(finalQR,
BarcodeFormat.QR_CODE,
QRCODE_IMAGE_WIDTH,
QRCODE_IMAGE_HEIGHT, hints);
int bitMatrixWidth = bitMatrix.getWidth();
int bitMatrixHeight = bitMatrix.getHeight();
int[] pixels = new int[bitMatrixWidth * bitMatrixHeight];
for (int y = 0; y < bitMatrixHeight; y++) {
int offset = y * bitMatrixWidth;
for (int x = 0; x < bitMatrixWidth; x++) {
pixels[offset + x] = bitMatrix.get(x, y) ?
getResources().getColor(R.color.colorPrimary) : getResources().getColor(R.color.colorPrimaryDark);
}
}
Bitmap bitmap = Bitmap.createBitmap(bitMatrixWidth, bitMatrixHeight, Bitmap.Config.ARGB_4444);
bitmap.setPixels(pixels, 0, 255, 0, 0, bitMatrixWidth, bitMatrixHeight);
Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.qr);
Bitmap bmOverlay = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), bitmap.getConfig());
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(bitmap, new Matrix(), null);
canvas.drawBitmap(bmp, 94, 94, null); //34x34
//canvas.drawBitmap(bmp, 86, 86, null); //42x42
if (bmOverlay != null) {
byte[] command = Utils.decodeBitmap(bmOverlay);
outputStream.write(ALLINEA_CT); //This command should center my QR, but it's not working
outputStream.write(command);
outputStream.write(FEED_LINE);
outputStream.write(FEED_LINE);
}
}catch (WriterException e){
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
位图解码：此方法有助于解码位图，
public static byte[] decodeBitmap(Bitmap bmp){
int bmpWidth = 255;
int bmpHeight = 255;
List<String> list = new ArrayList<>(); //binaryString list
StringBuffer sb;
int bitLen = bmpWidth / 8;
int zeroCount = bmpWidth % 8;
String zeroStr = "";
if (zeroCount > 0) {
bitLen = bmpWidth / 8 + 1;
for (int i = 0; i < (8 - zeroCount); i++) {
zeroStr = zeroStr + "0";
}
}
for (int i = 0; i < bmpHeight; i++) {
sb = new StringBuffer();
for (int j = 0; j < bmpWidth; j++) {
int color = bmp.getPixel(j, i);
int r = (color >> 16) & 0xff;
int g = (color >> 8) & 0xff;
int b = color & 0xff;
// if color close to white，bit='0', else bit='1'
if (r > 160 && g > 160 && b > 160)
sb.append("0");
else
sb.append("1");
}
if (zeroCount > 0) {
sb.append(zeroStr);
}
list.add(sb.toString());
}
List<String> bmpHexList = binaryListToHexStringList(list);
String commandHexString = "1D763000";
String widthHexString = Integer
.toHexString(bmpWidth % 8 == 0 ? bmpWidth / 8
: (bmpWidth / 8 + 1));
if (widthHexString.length() > 2) {
Log.e("decodeBitmap error", " width is too large");
return null;
} else if (widthHexString.length() == 1) {
widthHexString = "0" + widthHexString;
}
widthHexString = widthHexString + "00";
String heightHexString = Integer.toHexString(bmpHeight);
if (heightHexString.length() > 2) {
Log.e("decodeBitmap error", " height is too large");
return null;
} else if (heightHexString.length() == 1) {
heightHexString = "0" + heightHexString;
}
heightHexString = heightHexString + "00";
List<String> commandList = new ArrayList<String>();
commandList.add(commandHexString+widthHexString+heightHexString);
commandList.addAll(bmpHexList);
return hexList2Byte(commandList);
}
打印机命令
public class PrinterCommands {
public static final byte HT = 0x9;
public static final byte LF = 0x0A;
public static final byte CR = 0x0D;
public static final byte ESC = 0x1B;
public static final byte DLE = 0x10;
public static final byte GS = 0x1D;
public static final byte FS = 0x1C;
public static final byte STX = 0x02;
public static final byte US = 0x1F;
public static final byte CAN = 0x18;
public static final byte CLR = 0x0C;
public static final byte EOT = 0x04;
public static final byte[] INIT = {27, 64};
public static byte[] FEED_LINE = {10};
public static byte[] SELECT_FONT_A = {27, 33, 0};
public static byte[] FONT_B = {0x1B, 0x4D, 0x01};
public static byte[] ALLINEA_SX = {0x1B, 0x61, 0x00};
public static byte[] ALLINEA_CT = {0x1B, 0x61, 0x01};
public static byte[] ALLINEA_DX = {0x1B, 0x61, 0x02};
public static byte[] GRASSETTO_ON = {0x1B, 0x47, 0x11};
public static byte[] GRASSETTO_OFF = {0x1B, 0x47, 0x00};
public static byte[] SET_6 = {0x1B, 0x52, 0x06};
public static byte[] CODICI = {0x1B, 0x74, 0x13};
public static byte[] EURO = {(byte) 0xD5};
public static byte[] PALLINO = {(byte) 0x5B};
public static byte[] FONT_3X = {0x1D, 0x21, 0x21};
public static byte[] FONT_2X = {0x1D, 0x21, 0x11};
public static byte[] FONT_1X = {0x1D, 0x21, 0x00};
public static byte[] SET_BAR_CODE_HEIGHT = {29, 104, 100};
public static byte[] PRINT_BAR_CODE_1 = {29, 107, 2};
public static byte[] SEND_NULL_BYTE = {0x00};
public static byte[] SELECT_PRINT_SHEET = {0x1B, 0x63, 0x30, 0x02};
public static byte[] FEED_PAPER_AND_CUT = {0x1D, 0x56, 66, 0x00};
public static byte[] SELECT_CYRILLIC_CHARACTER_CODE_TABLE = {0x1B, 0x74, 0x11};
public static byte[] SELECT_BIT_IMAGE_MODE = {0x1B, 0x2F, 33, (byte) 255, 3};
public static byte[] SET_LINE_SPACING_24 = {0x1B, 0x33, 24};
public static byte[] SET_LINE_SPACING_30 = {0x1B, 0x33, 30};
public static byte[] TRANSMIT_DLE_PRINTER_STATUS = {0x10, 0x04, 0x01};
public static byte[] TRANSMIT_DLE_OFFLINE_PRINTER_STATUS = {0x10, 0x04, 0x02};
public static byte[] TRANSMIT_DLE_ERROR_STATUS = {0x10, 0x04, 0x03};
public static byte[] TRANSMIT_DLE_ROLL_PAPER_SENSOR_STATUS = {0x10, 0x04, 0x04};
public static final byte[] ESC_FONT_COLOR_DEFAULT = new byte[] { 0x1B, 'r',0x00 };
public static final byte[] FS_FONT_ALIGN = new byte[] { 0x1C, 0x21, 1, 0x1B, 0x21, 1 };
public static final byte[] ESC_ALIGN_LEFT = new byte[] { 0x1b, 'a', 0x00 };
public static final byte[] ESC_ALIGN_RIGHT = new byte[] { 0x1b, 'a', 0x02 };
public static final byte[] ESC_ALIGN_CENTER = new byte[] { 0x1b, 'a', 0x01 };
public static final byte[] ESC_CANCEL_BOLD = new byte[] { 0x1B, 0x45, 0 };
/*********************************************/
public static final byte[] ESC_HORIZONTAL_CENTERS = new byte[] { 0x1B, 0x44, 20, 28, 00};
public static final byte[] ESC_CANCLE_HORIZONTAL_CENTERS = new byte[] { 0x1B, 0x44, 00 };
/*********************************************/
public static final byte[] ESC_ENTER = new byte[] { 0x1B, 0x4A, 0x40 };
public static final byte[] PRINTE_TEST = new byte[] { 0x1D, 0x28, 0x41 };
}