如何在flutter/dart中对POST请求进行urlencode？

import 'package:http/http.dart' as http;

void main() async {
  // 构建请求参数
  Map<String, String> params = {
    'name': 'John Doe',
    'email': 'johndoe@example.com',
  };

  // 对请求参数进行urlencode
  String encodedParams = Uri(queryParameters: params).buildQueryParameters();

  // 构建请求URL
  String url = 'https://example.com/api';

  // 发起POST请求
  http.Response response = await http.post(
    Uri.parse(url),
    body: encodedParams,
    headers: {'Content-Type': 'application/x-www-form-urlencoded'},
  );

  // 处理响应
  if (response.statusCode == 200) {
    print('请求成功');
    print(response.body);
  } else {
    print('请求失败');
  }
}