未处理的异常: FormatException:无效的基数-10数字(位于字符1)

Question

我正在跟随这个颤动初学者教程，从我在斯里兰卡的时区here .But 5:30开始，所以我试图添加半个小时，但它一直收到这个错误，我无法修复。如果可以，请帮帮我！！。

完全回溯错误：

Performing hot restart...
Syncing files to device AOSP on IA Emulator...
Restarted application in 797ms.
E/flutter (31824): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: FormatException: Invalid radix-10 number (at character 1)
E/flutter (31824): 5:3
E/flutter (31824): ^
E/flutter (31824): 
E/flutter (31824): #0      int._throwFormatException (dart:core-patch/integers_patch.dart:131:5)
E/flutter (31824): #1      int._parseRadix (dart:core-patch/integers_patch.dart:142:16)
E/flutter (31824): #2      int._parse (dart:core-patch/integers_patch.dart:100:12)
E/flutter (31824): #3      int.parse (dart:core-patch/integers_patch.dart:63:12)
E/flutter (31824): #4      WorldTime.getTime (package:world_time_app/services/world_time.dart:24:39)
E/flutter (31824): <asynchronous suspension>
E/flutter (31824): #5      _LoadingState.SetupWorldTime (package:world_time_app/pages/loading.dart:14:3)
E/flutter (31824): <asynchronous suspension>
E/flutter (31824): 

代码：

import 'package:flutter/material.dart';
import 'package:http/http.dart';
import 'dart:convert';

class WorldTime{

  String location;
  String time;
  String flag;
  String url;

  WorldTime({this.location, this.flag, this.url});

  Future<void> getTime() async{

    Response response = await get('https://www.worldtimeapi.org/api/timezone/$url');
    Map data = jsonDecode(response.body.toString());
    //print(data);
    String datetime = data['datetime'];
    String offset = data['utc_offset'].substring(2,5);
    //print(dataTime);
    //print(offset);
    DateTime now = DateTime.parse(datetime);
    now = now.add(Duration(hours: int.parse(offset)));

    time = now.toString();
    print(time);



  }

}

Answer 1

您试图将5:3解析为int，这会导致错误。

问题出在返回无效数字(5:3)的子字符串中。

首先，您应该执行data['utc_offset'].substring(1,3)以仅获取小时数，执行data['utc_offset'].substring(4,6)以仅获取分钟数。

之后，您可以随心所欲地进行操作，例如：

String offsetHours = data['utc_offset'].substring(1, 3);
String offsetMinutes = data['utc_offset'].substring(4, 6);

DateTime now = DateTime.parse(datetime);
now = now.add(Duration(
  hours: int.parse(offsetHours), 
  minutes: int.parse(offsetMinutes)),
);

Answer 2

在我的例子中，我在authority参数中传递了子路由，如下所示：

var response =
          await http.get(Uri.https('https://favqs.com/api/quotes/', '4'), headers: {
        'Content-Type': 'application/json',
        'Authorization': "Token token='xxxxxxxxxxxxxxxx'",
      });

但是在删除第二个参数中的https并移动/api/quotes/之后，这个问题就解决了。

var response =
          await http.get(Uri.https('favqs.com', '/api/quotes/4'), headers: {
        'Content-Type': 'application/json',
        'Authorization': "Token token='xxxxxxxxxxxxxxxx'",
      });