我正在尝试从AMQP-CPP自述文件AMQP-CPP中编译一些示例代码。但是由于某种原因，我无法编译为TcpConnection给出的示例。一切看起来都很好，但我不断得到：
g++ --std=c++11 -Wall -lamqpcpp -lpthread -ldl -c main.cpp -o main.o
main.cpp:20:1: error: 'channel' does not name a type
channel.declareExchange("my-exchange", AMQP::fanout);
^~~~~~~
main.cpp:21:1: error: 'channel' does not name a type
channel.declareQueue("my-queue");
^~~~~~~
main.cpp:22:1: error: 'channel' does not name a type
channel.bindQueue("my-exchange", "my-queue", "my-routing-key");
相关代码：
//Main.cpp
#include "MyTcpHandler.h"
#include <amqpcpp.h>
#include <amqpcpp/linux_tcp.h>
#include <amqpcpp/linux_tcp/tcpchannel.h>
// create an instance of your own tcp handler
MyTcpHandler myHandler;
// address of the server
AMQP::Address address("amqp://guest:guest@localhost/vhost");
// create a AMQP connection object
AMQP::TcpConnection connection(&myHandler, address);
// and create a channel
AMQP::TcpChannel channel(&connection);
// use the channel object to call the AMQP method you like
channel.declareExchange("my-exchange", AMQP::fanout);
channel.declareQueue("my-queue");
channel.bindQueue("my-exchange", "my-queue", "my-routing-key");
~
// MyTcpHandler.h
#include <amqpcpp.h>
#include <amqpcpp/linux_tcp.h>
class MyTcpHandler : public AMQP::TcpHandler
{
/**
* Method that is called by the AMQP library when a new connection
* is associated with the handler. This is the first call to your handler
* @param connection The connection that is attached to the handler
*/
virtual void onAttached(AMQP::TcpConnection *connection) override
{
// @todo
// add your own implementation, for example initialize things
// to handle the connection.
}
/**
* Method that is called by the AMQP library when the TCP connection
* has been established. After this method has been called, the library
* still has take care of setting up the optional TLS layer and of
* setting up the AMQP connection on top of the TCP layer., This method
* is always paired with a later call to onLost().
* @param connection The connection that can now be used
*/
virtual void onConnected(AMQP::TcpConnection *connection) override
{
// @todo
// add your own implementation (probably not needed)
}
/**
* Method that is called when the secure TLS connection has been established.
* This is only called for amqps:// connections. It allows you to inspect
* whether the connection is secure enough for your liking (you can
* for example check the server certicate). The AMQP protocol still has
* to be started.
* @param connection The connection that has been secured
* @param ssl SSL structure from openssl library
* @return bool True if connection can be used
*/
virtual bool onSecured(AMQP::TcpConnection *connection, const SSL *ssl) override
{
// @todo
// add your own implementation, for example by reading out the
// certificate and check if it is indeed yours
return true;
}
/**
* Method that is called by the AMQP library when the login attempt
* succeeded. After this the connection is ready to use.
* @param connection The connection that can now be used
*/
virtual void onReady(AMQP::TcpConnection *connection) override
{
// @todo
// add your own implementation, for example by creating a channel
// instance, and start publishing or consuming
}
/**
* Method that is called by the AMQP library when a fatal error occurs
* on the connection, for example because data received from RabbitMQ
* could not be recognized, or the underlying connection is lost. This
* call is normally followed by a call to onLost() (if the error occured
* after the TCP connection was established) and onDetached().
* @param connection The connection on which the error occured
* @param message A human readable error message
*/
virtual void onError(AMQP::TcpConnection *connection, const char *message) override
{
// @todo
// add your own implementation, for example by reporting the error
// to the user of your program and logging the error
}
/**
* Method that is called when the AMQP protocol is ended. This is the
* counter-part of a call to connection.close() to graceful shutdown
* the connection. Note that the TCP connection is at this time still
* active, and you will also receive calls to onLost() and onDetached()
* @param connection The connection over which the AMQP protocol ended
*/
virtual void onClosed(AMQP::TcpConnection *connection) override
{
// @todo
// add your own implementation (probably not necessary, but it could
// be useful if you want to do some something immediately after the
// amqp connection is over, but do not want to wait for the tcp
// connection to shut down
}
/**
* Method that is called when the TCP connection was closed or lost.
* This method is always called if there was also a call to onConnected()
* @param connection The connection that was closed and that is now unusable
*/
virtual void onLost(AMQP::TcpConnection *connection) override
{
// @todo
// add your own implementation (probably not necessary)
}
/**
* Final method that is called. This signals that no further calls to your
* handler will be made about the connection.
* @param connection The connection that can be destructed
*/
virtual void onDetached(AMQP::TcpConnection *connection) override
{
// @todo
// add your own implementation, like cleanup resources or exit the application
}
/**
* Method that is called by the AMQP-CPP library when it wants to interact
* with the main event loop. The AMQP-CPP library is completely non-blocking,
* and only make "write()" or "read()" system calls when it knows in advance
* that these calls will not block. To register a filedescriptor in the
* event loop, it calls this "monitor()" method with a filedescriptor and
* flags telling whether the filedescriptor should be checked for readability
* or writability.
*
* @param connection The connection that wants to interact with the event loop
* @param fd The filedescriptor that should be checked
* @param flags Bitwise or of AMQP::readable and/or AMQP::writable
*/
virtual void monitor(AMQP::TcpConnection *connection, int fd, int flags) override
{
// @todo
// add your own implementation, for example by adding the file
// descriptor to the main application event loop (like the select() or
// poll() loop). When the event loop reports that the descriptor becomes
// readable and/or writable, it is up to you to inform the AMQP-CPP
// library that the filedescriptor is active by calling the
// connection->process(fd, flags) method.
}
};
我确定这是一些基本的c ++东西的基本误会，但我完全不知所措
您正在尝试在全局对象上调用成员函数：
channel.declareExchange("my-exchange", AMQP::fanout);
channel.declareQueue("my-queue");
channel.bindQueue("my-exchange", "my-queue", "my-routing-key");
将这些呼叫放入main()内部>
让我们看一下错误消息，“通道”的类型是什么？