如何格式化蓝牙便携式打印机?

how to format the Bluetooth portable printer?

我正在使用便携式打印机打印收据。不是很懂。。。

这是格式。

如何将 'Header 1' 字体设置为比其他字体大并且将所有 headers 设置为中间?

这里是代码

SQLiteDatabase db = mSQLiteHelper.getReadableDatabase();
            Cursor cursor = db.rawQuery("select * from Information", null);
            while (cursor.moveToNext()) {
                txn = new SettingModel();
                String header1 = (cursor.getString(cursor.getColumnIndex("header1")));
                String header2 = (cursor.getString(cursor.getColumnIndex("header2")));
                String header3 = (cursor.getString(cursor.getColumnIndex("header3")));
                String header4 = (cursor.getString(cursor.getColumnIndex("header4")));
                String txnNo = "TxnNo: " + D_Txn.getText().toString();
                String name = "Name: " + D_Name.getText().toString();
                String amount = "Amount: " + D_Amount.getText().toString();
                String Date = "Date: " + Select_Date.getText().toString();
                String Users = (cursor.getString(cursor.getColumnIndex("personInCharge")));
                String space = "";

                header1 += "\n";
                header2 += "\n";
                header3 += "\n";
                header4 += "\n";
                txnNo += "\n";
                name += "\n";
                amount += "\n";
                Date += "\n";
                Users += "\n";
                space += "\n";

                outputStream.write(header1.getBytes());
                outputStream.write(header2.getBytes());
                outputStream.write(header3.getBytes());
                outputStream.write(header4.getBytes());
                outputStream.write(txnNo.getBytes());
                outputStream.write(name.getBytes());
                outputStream.write(amount.getBytes());
                outputStream.write(Date.getBytes());
                outputStream.write(Users.getBytes());
                outputStream.write(space.getBytes());
                outputStream.write(space.getBytes());

                Toast.makeText(this, "Printing Text...", Toast.LENGTH_SHORT).show();

有没有办法放一个space?我使用的是空字符串,是否正确?

....set all headers to the middle?

要将文本设置为居中,请使用此

  byte[] center = new byte[]{0x1B, 'a', 0x01};

然后使用outputStream

  outputStream.write(center);
  outputStream.write(header1.getBytes());
              ...