Question

我正在做一些代码，我将输出重定向到文件，但是我使用fstream，ostream，streambuf（）得到错误。它说

- ＆＃34; fstream的＆＃34;含糊不清

- ＆＃34; ostream的＆＃34;含糊不清

-class＆＃34; std :: basic_ostream＆gt;＆＃34;没有会员＆＃34; streambuf＆＃34;

-class＆＃34; std :: shared_ptr＆＃34;没有会员＆＃34;关闭＆＃34;

我已经搜索了包含，安装了最新版本的卡萨布兰卡的休息api，...我仍然得到那些错误...它缺少一些包括？

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

- ＆＃34; fstream的＆＃34;含糊不清

- ＆＃34; ostream的＆＃34;含糊不清

-class＆＃34; std :: basic_ostream＆gt;＆＃34;没有会员＆＃34; streambuf＆＃34;

您正在与std::和卡萨布兰卡的concurrency::streams命名空间发生冲突，要么确保它们永远不会被using放入一个文件中，也不会明确地使用concurrency::streams < / p>

-class＆＃34; std :: shared_ptr＆＃34;没有会员＆＃34;关闭＆＃34;

但它没有！在->

上使用fileStream

编辑：我认为你的代码只是官方sample的略微修改版本，你可以仔细检查你是否正确

Answer 2

我有一个类似的问题，实际上，这全都与名称空间的声明和用法有关。

上面的评论只说明了一半。

这是我最终为该应用程序创建的内容，并且可以正常工作：- （使用VS2019）

//使用命名空间标准；

使用名称空间并发::流;

stringstreambuf缓冲区；

auto fileStream = std :: make_shared（）;

pplx :: task requestTask = fstream :: open_ostream（U（“ results.html”））。then（[=]（ostream outFile）

{ * fileStream = outFile; 等。。。

使用流保存到文件的c ++错误

2 个答案: