tryParseDouble static method
解析double,失败返回null
Implementation
static double? tryParseDouble(dynamic v) {
if (v is IntX) {
return v.toDouble();
} else if (v is int) {
return v.toDouble();
} else if (v is double) {
return v;
} else if (v is num) {
return v.toDouble();
} else if (v is String) {
return double.tryParse(v);
}
return null;
}