setPrintDirection method Null safety
设置打印方向
horizontalMirror
水平镜像打印
verticalReverse
垂直反向打印
Implementation
void setPrintDirection(bool horizontalMirror, bool verticalReverse) {
addString(
"DIRECTION ${verticalReverse ? 1 : 0},${horizontalMirror ? 1 : 0}\r\n");
}