http post json dart 错误：XMLHttpRequest 错误

Posted 2023-02-23

【中文标题】http post json dart 错误：XMLHttpRequest 错误

【英文标题】：http post json dart Error: XMLHttpRequest error

【发布时间】：2021-06-03 00:29:00

【问题描述】：

我想向服务器发送一个 http post 请求（json 格式），并使用 Flutter 和 dart 以 json 格式返回响应。 我有一个关于 C# 的代码，这是可行的

        var httpWebRequest = (HttpWebRequest)WebRequest.Create("https://mysite");
        httpWebRequest.ContentType = "application/json";
        httpWebRequest.Method = "POST";

        using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
        
            string json = "\"email\":\"[e-mail]\"," +
                          "\"password\":\"mypass\"," +"\"remember\":\"false\"";

            streamWriter.Write(json);
        

        var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
        using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
        
            var result = streamReader.ReadToEnd();
            Console.ReadLine(result.ToString());
        

在 php 上

        $data = array(
          'email'      => '[e-mail]',
          'password'    => 'mypass',
          'remember'       => 'false'
        );
        $options = array(
          'http' => array(
            'method'  => 'POST',
            'content' => json_encode( $data ),
            'header'=>  "Content-Type: application/json\r\n" .
             "Accept: application/json\r\n"
            ),
            "ssl"=>array(
                "verify_peer"=>false,
                "verify_peer_name"=>false,
            )
        );
        $url='https://mysite';
        $context  = stream_context_create( $options );
        $result = file_get_contents( $url, false, $context );
        $response = json_decode($result);
        var_dump($response);

但在飞镖上它不起作用

        var body = "\"email\":\"[e-mail]\"," +        "\"password\":\"mypass\"," +"\"remember\":\"false\"";

var url =
Uri.https('mysite', '/mypath');
Map<String,String> headers = 
  'Content-type' : 'application/json',
  'Accept': 'application/json',

;

http.Response response = await http.post(
    url,body:body,headers: headers);
print(response.body);

pubpecs.yaml：

http: ^0.13.0

我认为以下错误是由cors引起的，但我无法在服务器端解决它，因为我写了here

Error: XMLHttpRequest error.
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/_internal/js_dev_runtime/patch/core_patch.dart 906:28                get current
packages/http/src/browser_client.dart 71:22                                                                                                    <fn>
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/zone.dart 1613:54                                              runUnary
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 155:18                                        handleValue
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 707:44                                        handleValueCallback
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 736:13                                        _propagateToListeners
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/future_impl.dart 533:7                                         [_complete]
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/stream_pipe.dart 61:11                                         _cancelAndValue
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/async/stream.dart 1219:7                                             <fn>
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 324:14  _checkAndCall
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 329:39  dcall
C:/b/s/w/ir/cache/builder/src/out/host_debug/dart-sdk/lib/html/dart2js/html_dart2js.dart 37307:58                              <fn>


at Object.createErrorWithStack (http://localhost:57471/dart_sdk.js:5356:12)
at Object._rethrow (http://localhost:57471/dart_sdk.js:39475:16)
at async._AsyncCallbackEntry.new.callback (http://localhost:57471/dart_sdk.js:39469:13)
at Object._microtaskLoop (http://localhost:57471/dart_sdk.js:39301:13)
at _startMicrotaskLoop (http://localhost:57471/dart_sdk.js:39307:13)
at http://localhost:57471/dart_sdk.js:34814:9

【参考方案1】：

您必须在 Json 正文中转义反斜杠，如果这正是您要发送的正文：

 var body = "\\"email\":\\"[e-mail]\\"," +        "\\"password\\":\\"mypass\\"," +"\\"remember\\":\\"false\\"";

【讨论】：

此代码不起作用。如果我 print(body) 我得到以下字符串： "email":"[e-mail]","password":"mypass","re​​member":"false"

一开始我没有看到它，但是您正在将它作为字符流写入您的 C# 类的请求中。这是一个 curl 请求吗？

在 C# 和 php 中一切都对我有用，dart 不起作用

你能回答我的问题吗？因为，我相信 Dart http 本身并不支持 curl 请求。

本机没有，但 dart 有一个 curl 库 pub.dev/packages/curl。这是示例，对我不起作用：***.com/questions/63011704/flutter-curl-post-request