如何使用蓝牙热敏打印机打印发票收据

Question

I have to print invoice receipt using thermal printer. I have used Zjiang Thermal printer to print receipt. They also provide there manual & demo project. In demo project they use a libray "btsdk.jar" to implement connection & print.

I have successfully establish connection between printer & android device. But there is no guideline for text alignment (center, left, right) & cell width, height.

I have try it . It only change text height by changing format 2 variable.

How I print invoice by bluetooth printer.

please also explain this section-

 byte[] cmd = new byte[3];
 cmd[0] = 0x1b;
 cmd[1] = 0x21;
 cmd[2] |= 0x10;

cmd 2 - used for change font height what is use of cmd[0] & cmd 1

code to send Printing message to bluetooth Printer In Demo Project

 String msg = "";
 byte[] cmd = new byte[3];
 cmd[0] = 0x1b;
 cmd[1] = 0x21;
 cmd[2] |= 0x10;
 mService.write(cmd);           
 mService.sendMessage("Congratulations!\n", "GBK"); 
 cmd[2] &= 0xEF;
 mService.write(cmd);          
 msg = "  You have sucessfully created communications between your device and our bluetooth printer.\n\n"
      +"  the company is a high-tech enterprise which specializes" +
        " in R&D,manufacturing,marketing of thermal printers and barcode scanners.\n\n";
 mService.sendMessage(msg,"GBK");

Print Info-

       parameters:support to download the Logo trademark
       FontA:12*24 dots,1.5(W)*3.0(H) mm
       FontB:9*17 dots, 1.1(W)*2.1(H) mm
       Simplified/Traditional: 24*24 dots, 3.0(W)*3.0(H)
       Line spacing: 3.75mm (Default)
       Barcode Types:-
       1D Barcode- UPC-A/UPC-E, JAN13(EAN13), JAN8(EAN8), CODE39/ITF, CODABAR,CODE93
       2d Barcode- QR CODE

Invoice Receipt

Answer 1

I have found the following image over the internet for Text Alignment. Hope it helps

Answer 2

you can use this

void printLine(String txt, char type){
    byte[] format = { 27, 33, 0 };
    byte[] arrayOfByte1 = { 27, 33, 0 };

    if (type == 'b') {
        format[2] = ((byte) (0x8 | arrayOfByte1[2])); //BOLD
    }
    if (type == 'h') {
        format[2] = ((byte) (0x10 | arrayOfByte1[2])); //HEIGHT
    }
    if (type == 'w') {
        format[2] = ((byte) (0x20 | arrayOfByte1[2])); //WIDTH
    }
    if (type == 'u') {
        format[2] = ((byte) (0x80 | arrayOfByte1[2])); //UNDERLINE
    }
    if (type == 's') {
        format[2] = ((byte) (0x1 | arrayOfByte1[2])); //SMALL
    }
    mService.write(format);
    mService.sendMessage(txt,"GBK");
}

credit goes to Leonardo Sapuy and his original q/a Format text in bluetooth printer and thanks to Murtaza Khursheed Hussain for sending me to it