Structure with 0-ended string

[vitecd]

How can I create a structure with a String with an unknown length, please?

[vitecd]

not a 100 solution, but doing something with TerminatedCString

[dev747368]

you can do it that way, but if your struct (including string) is always the same fixed-length (your screenshot shows 32 bytes, so I'm guessing all instances might be this size), the plain "string" data type, with a field size of 22 might work better.