说明：  此类用于控制串行端口文件资源。 此类提供同步和事件驱动 I/O、 对插针和中断状态的访问和对串行驱动程序属性的访问。 此外，此类功能可以包装在一个内部 Stream 对象，可通过访问 BaseStream 属性，并传递到包装或使用流的类。 SerialPort 类支持以下编码︰ ASCIIEncoding, ，UTF8Encoding, ，UnicodeEncoding, ，UTF32Encoding, ，并在其中的代码页是小于 50000 或代码页是 54936 mscorlib.dll 中定义任何编码。 可以使用备用编码，但必须使用 ReadByte 或 Write 方法并执行自己的编码。 您使用 GetPortNames 方法来检索当前计算机的有效端口。 如果 SerialPort 对象被阻塞，在读取操作期间，不终止线程。 相反，请关闭基础流或释放 SerialPort 对象。
(This class is used to control the serial port file resources. This class provides synchronous and event driven I/O, access to pins and interrupt States, and access to serial driver properties. In addition, such functions can be wrapped in an internal Stream object, which can be accessed by accessing the BaseStream attribute and passing to the class that wrapper or use the stream. The SerialPort class supports the following code: ASCIIEncoding, UTF8Encoding, UnicodeEncoding, UTF32Encoding, and in which the code page is less than 50000 or the code page is 54936 mscorlib.dll to define any encoding. You can use alternate encoding, but you must use the ReadByte or Write method and execute your own encoding. You use the GetPortNames method to retrieve the valid port of the current computer. If the SerialPort object is blocked, the thread is not terminated during the read operation. Instead, close the underlying stream or release the SerialPort object.)