发送http请求时如何实现try语句?

Question

我想创建一个登录方法来发布http request。我使用以下代码将用户数据发布到服务器并获得响应:

import 'dart:convert';
import 'dart:html';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import '../Services/baseHttp.dart' as base;
class Services {
late var token = '';
Future<http.Response> login(String username, String password) async {
var url = base.BaseURL.loginUrl;
Map data = {"username": username, "password": password};
var body = json.encode(data);
var response = await http.post(Uri.parse(url),
headers: {
"Content-Type": "application/json",
"Accept": "application/json"
},
body: body);
print(response.statusCode);
token = response.body;
print(token);
return response;
}
}

我尝试在方法中使用try catch:

Future<http.Response> login(String username, String password) async {
try {
var url = base.BaseURL.loginUrl;
Map data = {"username": username, "password": password};
var body = json.encode(data);
var response = await http.post(Uri.parse(url),
headers: {
"Content-Type": "application/json",
"Accept": "application/json"
},
body: body);
print(response.statusCode);
token = response.body;
print(token);
return response;
} catch (e) {
print(e);
}
}

当抛出任何异常时，我想发送statusCode而不是print(e)。我该怎么做呢?

Answer 1

要检查响应是否有效，可以像这样检查状态码是否等于200:

if (response.statusCode == 200){
// Do something
} else {
// Throw exception
}

看一下官方文件。您将看到以下内容:

Future<Album> fetchAlbum() async {
final response = await http
.get(Uri.parse('https://jsonplaceholder.typicode.com/albums/1'));
if (response.statusCode == 200) {
// If the server did return a 200 OK response,
// then parse the JSON.
return Album.fromJson(jsonDecode(response.body));
} else {
// If the server did not return a 200 OK response,
// then throw an exception.
throw Exception('Failed to load album');
}
}