Windows Chrome扩展程序本机消息传递只能接收第一个响应

时间:2014-05-26 18:46:13

标签: windows google-chrome-extension chrome-native-messaging

我正在尝试使用本机消息传递将一些数据发送到我的本机Windows应用程序。它适用于runtime.sendNativeMessage()方法。当我尝试使用使用端口的长期连接时,它也可以将数据从chrome传递到我的应用程序。但是,Chrome扩展程序只能从我的应用程序收到第一个响应。我确信端口仍然处于打开状态,因为我的应用程序仍然可以从chrome接收数据。以下是我的代码:

Chrome扩展程序脚本:

var port = chrome.runtime.connectNative('com.mydomain.app1');

port.onMessage.addListener(function(msg) {
  console.log("Received from port:", msg);
});

port.onDisconnect.addListener(function() {
   console.log("Disconnected");
});

chrome.tabs.onUpdated.addListener(
   function(tabId, changeInfo, tab) {  
      var param = {};
      param['url'] = tab.url; 
      port.postMessage( param);   
   }
}

我在c ++中的Windows应用程序:

int _tmain(int argc, _TCHAR* argv[])
{
    while( true )
    {
         //read the first four bytes (=> Length)
         unsigned int length = 0;
         for (int i = 0; i < 4; i++)
         {
              char c;
              if( ( c=getchar()) != EOF) 
                  length += c<<i*8;
              else return 0;
          }

          //read the json-message
          std::string msg = "";
          for (int i = 0; i < length; i++)
          {
              msg += getchar();
          } 

          //.... do something

          //send a response message
          std::string message = "{\"text\": \"This is a response message\"}";
          unsigned int len = message.length();
          // We need to send the 4 bytes of length information
          std::cout << char(((len>>0) & 0xFF))
                    << char(((len>>8) & 0xFF))
                    << char(((len>>16) & 0xFF))
                    << char(((len>>24) & 0xFF));
           // Now we can output our message
           std::cout << message.c_str();
           std::cout.flush();

     }
}   

请注意最后一行&#34; std :: cout.flush(); &#34;,如果我将其评论出来,即使是第一个回复也不会被显示在铬。我只是无法弄清楚Chrome如何从应用程序的标准中读取。

1 个答案:

答案 0 :(得分:2)

尝试自动刷新 - std::cout.setf( std::ios_base::unitbuf )

此外,您读取/写入输入/输出消息长度的方式不正确,并且在长消息上将失败。

此代码适用于我:

int main(int argc, char* argv[])
{
    std::cout.setf( std::ios_base::unitbuf );

    while (true)
    {
        unsigned int ch, inMsgLen = 0, outMsgLen = 0;
        std::string input = "", response = "";

        // Read 4 bytes for data length
        std::cin.read((char*)&inMsgLen, 4);

        if (inMsgLen == 0)
        {
            break;
        }
        else
        {
            // Loop getchar to pull in the message until we reach the total length provided.
            for (int i=0; i < inMsgLen; i++)
            {
                ch = getchar();
                input += ch;
            }
        }

        response.append("{\"echo\":").append(input).append("}");

        outMsgLen = response.length();

        // Send 4 bytes of data length
        std::cout.write((char*)&outMsgLen, 4);

        // Send the data
        std::cout << response;
    }

    return 0;
}