Long string to PChar conversions are not automatic. Some of the differences between
strings and PChars can make conversions problematic:
Long strings are reference-counted, while PChars are not.
Assigning to a string copies the data, while a PChar is a pointer to memory.
Long strings are null-terminated and also contain the length of the string,
while PChars are simply null-terminated.
Situations in which these differences can cause subtle errors are discussed
in this section.
以上是Borland的官方解答。
