Converting String to Byte array won't work - installation

Question

I want to convert a String to a byte array, the code looks like the following:
procedure StringToByteArray(const s : String; var tmp: array of Byte);
var
i : integer;
begin
For i:=1 to Length(s) do
begin
tmp[i-1] := Ord(s[i]);
end;
end;
s[i] here is the i'th String element (= char at pos i) and I'm saving its numerical value to tmp.
This works for some characters, but not for all, for example:
Ord('•') returns Dec(149), which is what I expect.
But in my procedure Ord(s[i]) returns Dec(8226) for the same character!
Edit1: I think the defect lies in my other function "ByteArrayToStr"
When converting ...
tmp:= 149 // tmp is of type byte
Log('experiment: ' + Chr(tmp)); // prints "•"
Log('experiment2 ' + IntToStr(Ord(Chr(tmp)))); // prints 149
... back and forth, this seems to work.
But using the same conversion in the following function won't do it:
function ByteArrayToStr( a : array of Byte ) : String;
var
S:String;
I:integer;
begin
S:='';
For I:=0 to Length(a) -1 do
begin
tmp := Chr(a[I]) ; // for a[I] equals 149 this will get me "?" instead of "•"
S:=S+tmp;
end;
Result:=S;
end;
To make it clear: ByteArrayToStr does not convert Ord(149) to "•" as expected, and therefore StringToByteArray won't work later on

Answer 1

You need to turn your parameters into AnsiString type. By doing so, you can write functions like this:
[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program
OutputDir=userdocs:Inno Setup Examples Output
[Code]
procedure StringToByteArray(const S: AnsiString; out ByteArray: array of Byte);
var
I: Integer;
begin
SetArrayLength(ByteArray, Length(S));
for I := 1 to Length(S) do
ByteArray[I - 1] := Ord(S[I]);
end;
function ByteArrayToString(const ByteArray: array of Byte): AnsiString;
var
I: Integer;
begin
SetLength(Result, GetArrayLength(ByteArray));
for I := 1 to GetArrayLength(ByteArray) do
Result[I] := Chr(ByteArray[I - 1]);
end;
procedure InitializeWizard;
var
S: AnsiString;
ByteArray: array of Byte;
begin
S := '•';
StringToByteArray(S, ByteArray);
MsgBox(IntToStr(ByteArray[0]), mbInformation, MB_OK);
S := '';
S := ByteArrayToString(ByteArray);
MsgBox(S, mbInformation, MB_OK);
end;