python3.5 asyncio协议

Question

我想构建一个聊天演示，但我无法接收服务器端发送的东西，除了第一次启动，任何人都知道为什么？ 代码从https://docs.python.org/3.4/library/asyncio-protocol.html#tcp-echo-client-protocol

Server.py

import asyncio 

class EchoServerClientProtocol(asyncio.Protocol): 
    def connection_made(self, transport): 
     peername = transport.get_extra_info('peername') 
     print('Connection from {}'.format(peername)) 
     self.transport = transport 

    def data_received(self, data): 
     message = data.decode() 
     print('Data received: {!r}'.format(message)) 
     print('Send: {!r}'.format(message)) 
     self.transport.write(data) 


loop = asyncio.get_event_loop() 
# Each client connection will create a new protocol instance 
coro = loop.create_server(EchoServerClientProtocol, '127.0.0.1', 8888) 
server = loop.run_until_complete(coro) 

# Serve requests until Ctrl+C is pressed 
print('Serving on {}'.format(server.sockets[0].getsockname())) 
try: 
    loop.run_forever() 
except KeyboardInterrupt: 
    pass 

# Close the server 
server.close() 
loop.run_until_complete(server.wait_closed()) 
loop.close() 

Client.py

class EchoClientProtocol(asyncio.Protocol): 
    def __init__(self, message, loop): 
     self.message = message 
     self.loop = loop 
     self.transport = None 

    def connection_made(self, transport): 
     self.transport = transport 

     transport.write(self.message.encode()) 
     print('Data sent: {!r}'.format(self.message)) 

     # while 1: 
     #  message=input('please input the message:') 
     #  transport.write(message.encode()) 
     #  print('Data sent: {!r}'.format(message)) 

    def data_received(self, data): 
     # print('data_received') 
     print('Data received: {!r}'.format(data.decode())) 
     while 1: 
      message = input('please input the message:') 
      self.transport.write(message.encode()) 
      print('Data sent: {!r}'.format(message)) 

    def connection_lost(self, exc): 
     print('The server closed the connection') 
     print('Stop the event loop') 
     self.loop.stop() 

loop = asyncio.get_event_loop() 
message = 'Hello World!' 
coro = loop.create_connection(lambda: EchoClientProtocol(message, loop), 
           '127.0.0.1', 8888) 
loop.run_until_complete(coro) 
loop.run_forever() 
loop.close() 

结果显示： 斜面不显示 '收到的数据： '#####' 像' DEF data_received（self，data）'仅用于onece 任何人都有解决方案吗？ [结果] [1] [1]：https://i.stack.imgur.com/IoqA9.png

Answer 1

所创建所谓的从EchoClientProtocol.data_received()阻断功能。只有当事件循环可以处理它时，每个从服务器传递的消息都可以传递到EchoClientProtocol.data_received()，但阻止函数可以阻止它。

此代码从用户

while 1: # More Pythonic way is While True 
    message = input('please input the message:') 
    self.transport.write(message.encode()) 

获取消息，并将其发送到服务器，直到这一刻这一切都很好。在下一步中，它会启动另一个循环，但代码不会进入事件循环（所以传入的消息无法处理）。

您可以修改客户端的代码是这样的：当你从服务器接收Hello World!

def data_received(self, data): 
     print('Data received: {!r}'.format(data.decode())) 
     message = input('please input the message:') 
     self.transport.write(message.encode()) 

在客户端中的data_received首次调用（它的Hello World!从connection_made发送）。现在，处理以下内容：

1. 它打印接收到的信息（在第一次调用它的Hello World!）
2. 从用户那里得到新的消息
3. 它发送到服务器
4. 该函数返回和控制给予事件循环。
5. 服务器接收到新邮件并发送回客户端
6. 在客户端调用data_received
7. 转到步骤1