1、官方解释文档：

 

　　Blocking Master shows how to create an application for a serial interface using the synchronous API of  in a worker thread.

　　阻塞主程序显示了如何使用QSerialPort的同步API在同个工作线程中为串行接口创建应用程序。

　　

 supports two programming alternatives:

QSerialPort支持两种编程方法：

　　

• The asynchronous (non-blocking) alternative. Operations are scheduled and performed when the control returns to the Qt event loop. The class emits a signal when the operation is finished. For example, the  method returns immediately. When the data is sent to the serial port, the  class emits the  signal.
• The synchronous (blocking) alternative. In headless and multithreaded applications, the wait method can be called (in this case,) to suspend the calling thread until the operation has completed.
• 　　异步(不阻塞)二者选择一种。当控制返回到Qt事件循环时，调度并执行操作。QSerialPort类在操作完成时发出一个信号。例如，write（）方法立即返回。当数据被发送到串行端口时，QSerialPort类会发出bytes笔试（）信号。
• 　　同步(阻塞)的选择。在无头的和多线程的应用程序中，可以调用wait方法（在本例中，waitForReadyRead（））暂停呼叫线程，直到操作完成。