string property
String?
get
string
转换为一个可能为空的String类型
Implementation
String? get string {
if (rawValue is double) return '$rawValue';
if (rawValue is int) return '$rawValue';
if (rawValue is bool) return '$rawValue';
if (rawValue is num) return '$rawValue';
if (rawValue is String) return rawValue;
if (rawValue is List<dynamic>) return jsonEncode(rawValue);
if (rawValue is Map<dynamic, dynamic>) return jsonEncode(rawValue);
return null;
}