convert string to widestring in Delphi

[Sean]

I just wasted 4 hours so maybe I can save some of your time.
Assigning a string to a widestring such as in:

var
wString: wideString;
nString: string;
begin
nString := 'hello';
wString := nString;
end;

works fine UNLESS the nString is greater than 4096 characters, in
which case the assignment to wString results in a empty string.

Sean

[Mikael Mann]

delphicon...@yahoo.com (Sean) wrote in <c9b4f122.0302051151.7e92c8e7
@posting.google.com>:

What version of Delphi?

I have seen other problems with explicit conversion from WideString to
string, such as in: DoSomething([string(OneHelluvaWideString))]).

When the called function uses "array of const", and you include an
explicitly converted WideString as part of the array, all kinds of trouble
may occur - memory corruption, invalid string ref-counts etc. I've only
seen this happen in Delphi 5.0 though.

- M.m.

[Sean]

> What version of Delphi?
>
> I have seen other problems with explicit conversion from WideString to
> string, such as in: DoSomething([string(OneHelluvaWideString))]).
>
> When the called function uses "array of const", and you include an
> explicitly converted WideString as part of the array, all kinds of trouble
> may occur - memory corruption, invalid string ref-counts etc. I've only
> seen this happen in Delphi 5.0 though.

I'm using Delphi 5. I'm thinking it has more to do with a COM
limitation than a Delphi limitation because the WideString I was
assigning to was a parameter in a COM call.

Sean

[Mikael Mann]

delphicon...@yahoo.com (Sean) wrote in
<c9b4f122.03020...@posting.google.com>:

Funny you say that, because the WideString in my case was also coming from
a COM call (this was in a server-app).

My solution, anyways, was simply to drop the explicit conversion, and let
Delphi do the conversion automagically.

- M.m.