Flutter篇 Dart常见类型转换

int -> string

int age = 5;
String ageString = age.toString();//'5'

string -> int 

String  str = '100';
int strInt = int.parse(str); //100

String -> double

String str = '3.14';
double strDouble = double.parse(str);//3.14

double->String

double  pi =3.1415926;
String piStr = pi.toStringAsFixed(3); //保留小数点后3位，结果为3.141

int -> double

int age = 3;
double ageDouble = age.toDouble();//3.0

double -> int

double _dou = 20.34;
int i = _dou.round();

String -> Map

String str = '{"left":259.32,"top":196.92,"width":290,"height":263}';
Map<String,dynamic> strMap = jsonDecode(str);
print(strMap["left"]);//259.32

String -> List

String str = '[20,30,40,50]';
List<int> strList = <int>[];
for (var data in JsonDecoder().convert(str)) {
     strList.add(data);
};
strList.forEach((element) {
    print(element);
});
//20
//30
//40
//50