Azure C++；图书馆：；无效的streambuf对象“； 我试图用C++ Azure客户端库下载一个潜在的巨大Azure块BLB。它不起作用，因为我不知道如何用缓冲区大小初始化concurrency:：streams:：streambuf对象。我的代码如下所示： // Assume blockBlob has been created correctly. concurrency::streams::istream blobStream = blockBlob.open_read(); // I don't know how to initialize this streambuf: concurrency::streams::streambuf<uint8_t> dlStreamBuf; size_t nBytesReturned = 0, nBytesToRead = 65536; do { // This gets the exception "Invalid streambuf object": concurrency::task<size_t> returnedTask = blobStream.read(dlStreamBuf, nBytesToRead); nBytesReturned = returnedTask.get(); bytesSoFar += nBytesReturned; // Process the data in dlStreamBuf here... } while(nBytesReturned > 0); blobStream.close(); //假设blockBlob已正确创建。 并发：：流：：istream blobStream=blockBlob.open_read（）； //我不知道如何初始化此streambuf： 并发：：流：：streambuf dlStreamBuf； 大小nbytesreturn=0，nBytesToRead=65536； 做{ //这将获取异常“无效的streambuf对象”： 并发：：任务返回任务=blobStream.read（dlStreamBuf，nBytesToRead）； nBytesReturned=returnedTask.get（）； bytesSoFar+=N字节返回； //在此处处理dlStreamBuf中的数据。。。 }而（nbytesreturn>0）； blobStream.close（）； 注意，上面的流不与标准的C++流式混淆。

有人能就如何正确构造和初始化concurrency:：streams:：streambuf向我提供建议吗

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谢谢。

< P>我没有使用C++的流方法，但是C++文件中提到了下载文件或蒸汽>强> >/St>

两种方式。 下载到\u流方法例如：

    // Retrieve storage account from connection string.
azure::storage::cloud_storage_account storage_account = azure::storage::cloud_storage_account::parse(storage_connection_string);

// Create the blob client.
azure::storage::cloud_blob_client blob_client = storage_account.create_cloud_blob_client();

// Retrieve a reference to a previously created container.
azure::storage::cloud_blob_container container = blob_client.get_container_reference(U("my-sample-container"));

// Retrieve reference to a blob named "my-blob-1".
azure::storage::cloud_block_blob blockBlob = container.get_block_blob_reference(U("my-blob-1"));

// Save blob contents to a file.
concurrency::streams::container_buffer<std::vector<uint8_t>> buffer;
concurrency::streams::ostream output_stream(buffer);
blockBlob.download_to_stream(output_stream);

std::ofstream outfile("DownloadBlobFile.txt", std::ofstream::binary);
std::vector<unsigned char>& data = buffer.collection();

outfile.write((char *)&data[0], buffer.size());
outfile.close();  

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streambuf似乎是一个模板类。请尝试以下方法：

    concurrency::streams::container_buffer<std::vector<uint8_t>> output_buffer;
    size_t nBytesReturned = 0, nBytesToRead = 65536;
    do {
        // This gets the exception "Invalid streambuf object": 
        concurrency::task<size_t> returnedTask = stream.read(output_buffer, nBytesToRead);
        nBytesReturned = returnedTask.get();
        bytesSoFar += nBytesReturned;
        // Process the data in dlStreamBuf here...
    } while (nBytesReturned > 0);
    stream.close();

concurrency:：streams:：container\u buffer output\u buffer；
大小nbytesreturn=0，nBytesToRead=65536；
做{
//这将获取异常“无效的streambuf对象”：
并发：：task returnedTask=stream.read（输出缓冲区，nBytesToRead）；
nBytesReturned=returnedTask.get（）；
bytesSoFar+=N字节返回；
//在此处处理dlStreamBuf中的数据。。。
}而（nbytesreturn>0）；
stream.close（）；

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示例代码如下：

谢谢，但我希望有一个逐缓冲区的“读取”类型接口，以匹配当前应用程序的工作方式。还在研究……谢谢，@sguler！这确实可以编译。现在，我正试图找出如何将输出缓冲区中的数据放入实际缓冲区（无符号字符数组）。。。

    concurrency::streams::container_buffer<std::vector<uint8_t>> output_buffer;
    size_t nBytesReturned = 0, nBytesToRead = 65536;
    do {
        // This gets the exception "Invalid streambuf object": 
        concurrency::task<size_t> returnedTask = stream.read(output_buffer, nBytesToRead);
        nBytesReturned = returnedTask.get();
        bytesSoFar += nBytesReturned;
        // Process the data in dlStreamBuf here...
    } while (nBytesReturned > 0);
    stream.close();