Stream. Read Byte 方法
从流中读取一个字节，并将流内的位置向前提升一个字节，或者如果已到达流结尾，则返回 -1。Reads a byte from the stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream.
public: override int ReadByte();
public override int ReadByte ();
override this.ReadByte : unit -> int
Public Overrides Function ReadByte () As Integer
Int32 的无符号字节，如果到达流的末尾，则为 -1。The unsigned byte cast to an
Int32, or -1 if at the end of the stream.
流不支持读取。The stream does not support reading.
在流关闭后调用方法。Methods were called after the stream was closed.