异步函数
- JavaScript中，异步调用通过Promise来实现
- async函数返回一个Promise。await用于等待Promise
- Dart中，异步调用通过Future 来实现
- async函数返回一个Future，await用于等待Future
- Future详情
then
import 'package:http/http.dart' as http;
import 'dart:convert';
Future getIPAddress() {
final urls = 'https://httpbin.org/ip';
return http.get(urls).then((response) {
// print(response.body);
String ip=jsonDecode(response.body)['origin'];
return ip;
});
}
void main(){
getIPAddress()
.then((ip) => print('$ip'))
.catchError((error)=>print(error));
}
async
import 'package:http/http.dart' as http;
import 'dart:convert';
Future getIPAddress() async {
final urls = 'https://httpbin.org/ip';
final response = await http.get(urls);
String ip = jsonDecode(response.body)['origin'];
return ip;
}
void main() async {
try {
final ip = await getIPAddress();
print(ip);
} catch (error) {
print(error);
}
}
