配置
1、打开项目中 pubspec.yaml 文件
-
2、找到 dependencies (第三方框架管理)
在 dependencies 下面添加
dio: ^1.0.0或dio: 1.0.0（具体格式：name：^+version），如下图所示
pubspec dependencies
封装
- http_utils - A HTTP tool to receive data, download and upload files, etc.
Next, the source code is shown as follows:
//
// Created by dyf on 2018/9/3.
// Copyright (c) 2018 dyf.
//
import 'dart:io';
import 'package:cookie_jar/cookie_jar.dart';
import 'package:dio/dio.dart';
export 'package:dio/dio.dart';
export 'dart:io';
// ===============================================
// Response callbacks the http info.
// ===============================================
/// When data is received, it is called.
typedef void OnResponseSuccess(Response response);
/// When the request fails, it is called.
typedef void OnResponseError(DioError error);
/// Defines a HTTP tool to receive data, download and upload files, etc.
class HttpUtils {
/// Request base url, it can contain sub path, like: "https://www.google.com/api/".
String baseUrl;
/// Timeout in seconds for opening url.
int connectTimeout;
/// This is not the receiving time limitation, in seconds.
int receiveTimeout;
/// Http request headers.
Map<String, dynamic> headers;
/// The request Content-Type. The default value is [ContentType.json].
/// If you want to encode request body with "application/x-www-form-urlencoded",
/// you can set `ContentType.parse("application/x-www-form-urlencoded")`, and [Dio]
/// will automatically encode the request body.
ContentType contentType;
/// Cookie manager for http requests。Learn more details about
/// CookieJar please refer to [cookie_jar](https://github.com/flutterchina/cookie_jar)
CookieJar cookieJar;
/// A powerful Http client.
Dio _dio;
/// You can cancel a request by using a cancel token.
CancelToken _cancelToken;
/// Each Dio instance has a interceptor by which you can intercept requests or responses before they are
/// handled by `then` or `catchError`. the [interceptor] field
/// contains a [RequestInterceptor] and a [ResponseInterceptor] instance.
Interceptor get interceptor => _dio.interceptor;
/// If the `url` starts with "http(s)", the `baseURL` will be ignored, otherwise,
/// it will be combined and then resolved with the baseUrl.
String url = "";
/// Success response callback.
OnResponseSuccess _onSuccess;
/// Failure response callback.
OnResponseError _onError;
/// Constructor
HttpUtils({
this.baseUrl,
this.connectTimeout: 0,
this.receiveTimeout: 0,
this.headers,
this.contentType,
this.cookieJar
});
/// Named constructor
HttpUtils.config({
String baseUrl,
int connectTimeout: 0,
int receiveTimeout: 0,
Map<String, dynamic> headers,
ContentType contentType,
CookieJar cookieJar
}) : connectTimeout = 0,
receiveTimeout = 0 {
if (baseUrl != null) {
this.baseUrl = baseUrl;
}
if (connectTimeout > 0) {
this.connectTimeout = connectTimeout;
}
if (receiveTimeout > 0) {
this.receiveTimeout = receiveTimeout;
}
if (headers != null) {
this.headers = headers;
}
if (contentType != null) {
this.contentType = contentType;
}
if (cookieJar != null) {
this.cookieJar = cookieJar;
}
}
void _init() {
_cancelToken = new CancelToken();
// Create Dio instance with default [Options].
_dio = new Dio();
}
void _mergeOptions() {
if (baseUrl != null) {
_dio.options.baseUrl = baseUrl;
}
if (connectTimeout > 0) {
_dio.options.connectTimeout = 1000 * connectTimeout;
}
if (receiveTimeout > 0) {
_dio.options.receiveTimeout = 1000 * receiveTimeout;
}
if (headers != null) {
_dio.options.headers = headers;
}
if (contentType != null) {
_dio.options.contentType = contentType;
}
}
String _checkPath(String path) {
if (baseUrl != null && baseUrl.isNotEmpty && path.contains(baseUrl)) {
url = path;
} else {
url = (baseUrl ?? "") + path;
}
return url;
}
void _checkCookie() {
if (cookieJar != null) {
_dio.cookieJar = cookieJar;
}
}
/// Callback to listen the http info.
void listen(OnResponseSuccess onSuccess, OnResponseError onError) {
_onSuccess = onSuccess;
_onError = onError;
}
/// Handy method to make http GET request.
void get(String path, {data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.get(url, data: data, cancelToken: _cancelToken);
} else {
response = await _dio.get(url, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Handy method to make http POST request.
void post(String path, {data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.post(url, data: data, cancelToken: _cancelToken);
} else {
response = await _dio.post(url, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Handy method to make http PUT request.
void put(String path, {data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.put(url, data: data, cancelToken: _cancelToken);
} else {
response = await _dio.put(url, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Handy method to make http HEAD request.
void head(String path, {data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.head(url, data: data, cancelToken: _cancelToken);
} else {
response = await _dio.head(url, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Handy method to make http DELETE request.
void delete(String path, {data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.delete(url, data: data, cancelToken: _cancelToken);
} else {
response = await _dio.delete(url, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Handy method to make http PATCH request.
void patch(String path, {data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.patch(url, data: data, cancelToken: _cancelToken);
} else {
response = await _dio.patch(url, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Download the file and save it in local. The default http method is "GET".
void download(String path, String savePath, {OnDownloadProgress onProgress, data}) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
var response;
if (data != null) {
response = await _dio.download(url, savePath,
onProgress: onProgress, cancelToken: _cancelToken, data: data);
} else {
response = await _dio.download(url, savePath,
onProgress: onProgress, cancelToken: _cancelToken);
}
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Handy method to make http POST request.
/// [UploadFileInfo] Describes the info of file to upload,
/// e.g.: UploadFileInfo(new File("./example/upload.txt"), "upload.txt").
void upload(String path, Map<String, dynamic> data) async {
try {
_init();
_mergeOptions();
_checkCookie();
var url = _checkPath(path);
FormData formData = new FormData.from(data);
var response =
await _dio.post(url, data: formData, cancelToken: _cancelToken);
if (_onSuccess != null) _onSuccess(response);
} on DioError catch (e) {
if (_onError != null) _onError(e);
}
}
/// Cancel the request.
void cancel() {
_cancelToken.cancel();
}
}
使用示例
- HttpUtils 示例
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
String _data = "";
void _getTokenData() {
var baseUrl = "https://etherscan.io";
var httpUtils = new HttpUtils.config(baseUrl: baseUrl);
httpUtils.connectTimeout = 10;
// httpUtils.contentType = ContentType.html;
// 0x71c7656ec7ab88b098defb751b7401b5f6d8976f
httpUtils.get("/address/0x71c7656ec7ab88b098defb751b7401b5f6d8976f");
print("url: ${httpUtils.url}");
httpUtils.listen((Response response) {
String data = response.data;
//print("data: $data");
setState(() {
_data = data;
});
}, (DioError error) {
print("e: ${error.message}");
});
}
void _getTokenholdingsData() async {
String a = "0x71c7656ec7ab88b098defb751b7401b5f6d8976f";
String data = await EthTokenholdingsDataRequest.init(a).getData();
if (data != null && data.isNotEmpty) {
EthTokenholdingsParser.parse(data, a);
}
}
@override
void initState() {
super.initState();
_getTokenData();
_getTokenholdingsData();
}
void _incrementCounter() {
if (_data.isNotEmpty) {
EthTokenParser.parse(_data).then<bool>((finished){
if (finished) {
Navigator.push(context, _createPushRoute());
}
});
} else {
print("data is empty.");
}
}
MaterialPageRoute _createPushRoute() {
return MaterialPageRoute(builder: (context) =>
new EthTokensDisplayView("0x71c7656ec7ab88b098defb751b7401b5f6d8976f")
);
}
@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppConfigurator('UI').createAppBar(
title: new Text(widget.title, style: new TextStyle(fontSize: 18.0),)
),
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Text(
'You have pushed the button this many times:',
),
new Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: new FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: new Icon(Icons.add),
),
);
}
}
- dio 示例
//
// Created by dyf on 2018/9/7.
// Copyright (c) 2018 dyf.
//
import 'dart:async';
import 'package:dio/dio.dart';
import 'package:html/parser.dart' as html;
import './HtmlConverter.dart';
import './ExtendedUtility.dart';
class EthTokenholdingsDataRequest {
String _address;
EthTokenholdingsDataRequest(String address) {
_address = address;
}
EthTokenholdingsDataRequest.init(String address)
: this(address);
int _getCount(String input) {
return ExtendedString(input).toInt();
}
int _getRow(String input) {
var dom = html.parse(input);
List tbodyList = dom.getElementsByTagName("tr");
return tbodyList.length;
}
int _getTotalPage(int count, int row) {
double doub = count / row;
int page = count ~/ row;
if (doub > page) {
page += 1;
}
return page;
}
String _getUrl(int page) {
String baseUrl = "https://etherscan.io";
var a = "&a=" + _address;
var q = "&q=";
var p = "&p=$page";
var f = "&f=";
var h = "&h=";
var fav = "&fav=";
var s = "&sort=total_price_usd";
var o = "&order=desc";
var url = baseUrl + "/tokenholdingsHandler.ashx?" + a + q + p + f + h + fav + s + o;
return url;
}
String _convertToHtml(String input) {
return new HtmlConverter.init(input).convert(isTable: true);
}
Future<dynamic> _doDataRequest(int p) async {
try {
var dio = new Dio();
dio.options.connectTimeout = 5*1000;
var url = _getUrl(p);
print("url: $url");
Response response = await dio.get(url);
return response;
} on DioError catch(e) {
return e;
}
}
Future<String> getData() async {
var ret = await _doDataRequest(1);
if (ret is Response) {
var data = ret.data;
if (data != null && data is Map && data.isNotEmpty) {
var records = data["recordsfound"];
int count = _getCount(records);
if (count > 0) {
var tbody = data["layout"];
int row = _getRow(_convertToHtml(tbody));
int page = _getTotalPage(count, row);
String allData = await _getOtherData(tbody, page);
return _convertToHtml(allData);
}
}
} else {
print("e: ${ret.toString()}");
}
return null;
}
Future<String> _getOtherData(String baseData, int p) async {
String retData = baseData;
for (int i = 2; i < p + 1; i++) {
var ret = await _doDataRequest(i);
if (ret is Response) {
var data = ret.data;
if (data is Map) {
var tbody = data["layout"];
retData += tbody;
}
} else {
print("e: ${ret.toString()}");
}
}
return retData;
}
}
写的有不好的地方希望大家指出，我会更正，大家有什么看不明白的，也可以在评论里面提问，我会尽力解答。
点赞+关注，第一时间获取技术干货和最新知识点，谢谢你的支持！
最后祝大家生活愉快~
