最近在使用qt coding一个项目时，使用到了qtcpsocket模块来编写客户端与服务器。在windows平台下还能正常工作，但是在ubuntu平台下，客户端提示已连接时，服务器却没有响应。经过排查，发现是在重写qtcpsocket的incomingConnection函数时出现问题，incomingConnection(int handle)，应改为incomingConnection(qintptr handle)。以下是qintptr的官方解释：

Integral type for representing pointers in a signed integer (useful for hashing, etc.).
Typedef for either qint32 or qint64. This type is guaranteed to be the same size as a pointer on all platforms supported by Qt. On a system with 32-bit pointers, qintptr is a typedef for qint32; on a system with 64-bit pointers, qintptr is a typedef for qint64.
Note that qintptr is signed. Use quintptr for unsigned values.