Post 数据到 json api 使用 flutter

Question

我正在开发一个 flutter 项目，我想使用以下代码向 json api 添加数据：

save() async {
    try{
    var sendString =
        {
        'userId': userId,
        'userEmail': userEmail,
      };
    final response = await http.post(
      Uri.parse('http://localhost:5000/createapp'),
      headers: <String, String>{
        "ContentType": 'application/json; charset=UTF-8',
        "Access-Control-Allow-Origin": "*",
        "Access-Control-Allow-Credentials": "true",
        "Access-Control-Allow-Headers": "Origin,Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token,locale",
        "Access-Control-Allow-Methods": "POST, OPTIONS",
      },
      body: sendString,
    );
    print(response.body);
      }catch(e){
      print(e);
    }
  }

但是它在我的 flutter 控制台中给了我这个错误我不知道是什么问题，非常感谢任何帮助：

Posting data...
<!doctype html>
<html lang=en>
<title>400 Bad Request</title>
<h1>Bad Request</h1>
<p>The browser (or proxy) sent a request that this server could not understand.</p>

Answer 1

将正文编码为 JSON。

body: jsonEncode(sendString),

详情见Sending data to server。

Post 数据到 json api 使用 flutter

Post data to json api using flutter

json

dart

flutter