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POAccessing the member of a class that is part of a WiFi listener callback member function
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  1. POAccessing the member of a class that is part of a WiFi listener callback member function
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    copied!<p>I have a WiFi Listener registered as a callback (pointer function) with a fixed 3rd party interface. I used a static member of my function to register the callback function and then that static function calls a nonstatic member through a static cast. The main problem is that I cannot touch the resulting char * buff with any members of my class nor can I even change an int flag that is also a member of my class. All result in runtime access violations. What can I do? Please see some of my code below. Other problems are described after the code.</p> <pre><code>void *pt2Object; TextWiFiCommunication::TextWiFiCommunication() { networkDeviceListen.rawCallback = ReceiveMessage_thunkB; /* some other initializing */ } int TextWiFiCommunication::ReceiveMessage_thunkB(int eventType, NETWORK_DEVICE *networkDevice) { if (eventType == TCP_CLIENT_DATA_READY) static_cast&lt;TextWiFiCommunication *&gt;(pt2Object)-&gt;ReceiveMessageB(eventType,networkDevice); return 1; } int TextWiFiCommunication::ReceiveMessageB(int eventType, NETWORK_DEVICE *networkDevice) { unsigned char outputBuffer[8]; // function from an API that reads the WiFi socket for incoming data TCP_readData(networkDevice, (char *)outputBuffer, 0, 8); std::string tempString((char *)outputBuffer); tempString.erase(tempString.size()-8,8); //funny thing happens the outputBuffer is double in size and have no idea why if (tempString.compare("facereco") == 0) cmdflag = 1; return 1; } </code></pre> <p>So I can't change the variable cmdflag without an access violation during runtime. I can't declare outputBuffer as a class member because nothing gets written to it so I have to do it within the function. I can't copy the outputBuffer to a string type member of my class. The debugger shows me strlen.asm code. No idea why. How can I get around this? I seem to be imprisoned in this function ReceiveMessageB. </p> <p>Thanks in advance!</p> <p>Some other bizzare issues include: Even though I call a buffer size of 8. When I take outputBuffer and initialize a string with it, the string has a size of 16.</p>
 

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