c++ - 将无符号的 short/int 转换为 char *

Question

我有这样的功能

void UnitTestWorker::constructTestPayload(QByteArray &payload)
{
    QString List = "127.0.0.1";
    unsigned short Port = 12344;
    unsigned int RequestId = 1;
    memcpy(payload.data(),reinterpret_cast<char*>Port,sizeof(Port));
    memcpy(payload.data()+sizeof(Port),reinterpret_cast<char*>RequestId ,sizeof(RequestId ));
}

但是我收到访问冲突错误，似乎我不能做类似reinterpret_cast<char*>Portor的事情reinterpret_cast<char*>RequestId。

Answer 1

你必须确保它QByteArray &payload有足够的大小来接收你字节复制到它的数据：

if (payload.size()<sizeof(Port)+sizeof(RequestId)) 
    throw exception ("Ouch !! payload too small"); 
memcpy(payload.data(),reinterpret_cast<char*>(&Port),sizeof(Port));
memcpy(payload.data()+sizeof(Port),reinterpret_cast<char*>(&RequestId) ,sizeof(RequestId ));