c++使用流保存到文件时出错

Question

我正在编写一些将输出重定向到文件的代码，但使用 fstream、ostream、streambuf() 时出现错误。上面写着

-“fstream”有歧义

-“ostream”含糊不清

-class "std::basic_ostream>"没有成员 "streambuf"

-类“std::shared_ptr”没有成员“close”

我已经在其中搜索了 include，安装了最新版本的 casablanca 的 rest api，......但我仍然遇到这些错误......它缺少一些 include？

这是代码

#include <sstream>
#include <iostream>
#include <fstream>
#include <cpprest/http_client.h>
#include <cpprest/filestream.h>
#include <cpprest/http_listener.h>              // HTTP server
#include <cpprest/json.h>                       // JSON library
#include <cpprest/uri.h>                        // URI library
#include <cpprest/ws_client.h>                  // WebSocket client
#include <cpprest/containerstream.h>            // Async streams backed by STL containers
#include <cpprest/interopstream.h>              // Bridges for integrating Async streams with STL and WinRT streams
#include <cpprest/rawptrstream.h>               // Async streams backed by raw pointer to memory
#include <cpprest/producerconsumerstream.h>     // Async streams for producer consumer scenarios


using namespace utility;                    // Common utilities like string conversions
using namespace web;                        // Common features like URIs.
using namespace web::http;                  // Common HTTP functionality
using namespace web::http::client;          // HTTP client features
using namespace concurrency::streams;       // Asynchronous streams

using namespace web::http::experimental::listener;          // HTTP server
using namespace web::experimental::web_sockets::client;     // WebSockets client
using namespace web::json;



//Method

    auto fileStream = std::make_shared<std::ostream>();

    // Open stream to output file.
    pplx::task<void> requestTask = fstream::open_ostream(U("results.html")).then([=](ostream outFile)  //Error here on the fstrea and ostream
    {
        *fileStream = outFile;

        // Create http_client to send the request.
        http_client client(U("http://localhost:53213"));

        // Build request URI and start the request.
        uri_builder builder(U("/search"));
        builder.append_query(U("q"), U("cpprestsdk github"));
        return client.request(methods::GET, builder.to_string());
    })

        // Handle response headers arriving.
        .then([=](http_response response)
    {
        printf("Received response status code:%u\n", response.status_code());

        // Write response body into the file.
        return response.body().read_to_end(fileStream->streambuf());  //Error here on streambuf
    })

        // Close the file stream.
        .then([=](size_t)
    {
        return fileStream.close();  //Error on close

    });

    // Wait for all the outstanding I/O to complete and handle any exceptions
    try
    {
        requestTask.wait();
    }
    catch (const std::exception &e)
    {
        printf("Error exception:%s\n", e.what());
    }

Answer 1

-"fstream" is ambiguous

-"ostream" is ambiguous

-class "std::basic_ostream>" has no member "streambuf"

你正在冲突 std:: 和 casablanca 的 concurrency::streams 命名空间，要么确保它们永远不会被拉入 using in one文件或显式使用 concurrency::streams

-class "std::shared_ptr" has no member "close"

但事实并非如此!在你的 fileStream

上使用 ->

---

编辑:我认为您的代码只不过是官方 sample 的略微修改版本, 你可以仔细检查你是否做对了