How to Trim japanese character space(double byte character)?

Is it Unicode or not? If this is Unicode, there are no double-byte or single-byte characters. The size if a character is defined by a particular UTF. The notion of "character" in Unicode is purely cultural (abstracted from a particular glyph, style, etc.); so Unicode defines a one-to-one correspondence between such characters and "code points", which are integer numbers understood in its purely abstract mathematical sense, abstracted from any computer representation, size, etc. Computer representation is defined by one or another UTF.

So, if this is Unicode, please 1) tell us the exact integer value of the code point, 2) explain what is the problem if trimming? Why MFC? Does it mean that you are not using std::string?

—SA

"Not working" is not informative. After all, you only need to make a string less by one character and move data...
—SA