Method GetPinnableReference
GetPinnableReference()
Returns a reference to the 0th element of the span. If the span is empty, returns null reference. It can be used for pinning and is required to support the use of span within a fixed statement (返回对跨度的第0个元素的引用。如果跨度为空，则返回null引用. 它可用于固定，并且需要支持在 fixed 语句中使用跨度).
public ref byte GetPinnableReference()