formatNum static method
Implementation
static formatNum(double num, int postion) {
if ((num.toString().length - num.toString().lastIndexOf(".") - 1) <
postion) {
//小数点后有几位小数
print(num.toStringAsFixed(postion)
.substring(0, num.toString().lastIndexOf(".") + postion + 1)
.toString());
} else {
print(num.toString()
.substring(0, num.toString().lastIndexOf(".") + postion + 1)
.toString());
}
}