I used to use Widestring in VCL.

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I used to use Widestring in VCL.
Now that I work more in Firemonkey I used String.
I understand that new String=UnicodeString and ld String=AnsiString but I have class interfaces and libraries that use WideString declarations.
Is it recomended to use Widestring in Firemonkey or leave declarations as String?

Comments

  1. Микола ПетрівськийMarch 21, 2018 at 10:23 AM

    UnicodeString is faster and consumes less memorry than WideString.

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  2. David HeffernanMarch 21, 2018 at 11:51 AM

    Use WideString with COM or if you have pre Unicode Delphi. And nowhere else.

    It was never appropriate to use it with VCL unless you used TnT Unicode controls.

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  3. Arthur HoornwegMarch 21, 2018 at 2:59 PM

    Widestrings are also appropriate in interfaces shared between executables and dll's (with or without com). For everything else, unicodestrings are better.

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  4. David HeffernanMarch 21, 2018 at 3:52 PM

    Arthur Hoornweg Unless you want to use them as return values ........ See my well known SO post.

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  5. Arthur HoornwegMarch 22, 2018 at 1:20 AM

    David Heffernan I assume you're referring to the fact that Delphi implements certain function result types as OUT parameters? If both the DLL and the executable were written in Delphi, one would probably never notice.... In all other cases, yes, GPF's would fly.

    BTW a co-worker of mine needed an implementation of Gnu Gettext a couple of years ago for his Visual Basic 6 executable. He had seen that I use dxGettext for localizing my software and he wanted to do the same.

    I developed that as a Delphi 2007 DLL. It turned out that the simplest way of handling the string stuff was by using pAnsiChar as input parameters and Olevariant as the result type. VB happily accepted the widestrings once they were wrapped in variants.

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  6. David HeffernanMarch 22, 2018 at 1:45 AM

    Arthur Hoornweg Certainly BSTR is very useful for interop, but there are some details you have to straighten out.

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  7. R GospMarch 22, 2018 at 10:34 AM

    I will prefer using Widestring in COM, Interfaces and as return variables.
    Thanks for comments.

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  8. David HeffernanMarch 22, 2018 at 10:36 AM

    R Gosp No. Not as function return values. Don't do that. Use Widestring for interop with other modules (e.g. DLLs) and for COM interfaces. That's it.

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  9. R GospMarch 22, 2018 at 10:44 AM

    David Heffernan I meant that

    ReplyDelete

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