delphi 字符串string转流TStream

function StringToFile(mString : string; mFileName : TFileName) : Boolean;
var
vFileChar : file of Char;
I : Integer;
begin
{$I-}
AssignFile(vFileChar , mFileName);
Rewrite(vFileChar);
for I := 1 to Length(mString) do
Write(vFileChar , mString[I]);
CloseFile(vFileChar);
{$I+}
Result := (IOResult = 0) and (mFileName <> '');
end;

function FileToString(mFileName : TFileName) : string;
var
vFileChar : file of Char;
vChar : Char;
begin
Result := '';
{$I-}
AssignFile(vFileChar , mFileName);
Reset(vFileChar);
while not Eof(vFileChar) do
begin
Read(vFileChar , vChar);
Result := Result + vChar;
end;
CloseFile(vFileChar);
{$I+}
end;

function StreamToString(mStream : TStream) : string;
var
I : Integer;
begin
Result := '';
if not Assigned(mStream) then Exit;
SetLength(Result , mStream.Size);
for I := 0 to Pred(mStream.Size) do
try
mStream.Position := I;
mStream.Read(Result[Succ(I)] , 1);
except
Result := '';
end;
end;

function StringToStream(mString : string; mStream : TStream) : Boolean;
var
I : Integer;
begin
Result := True;
try
mStream.Size := 0;
mStream.Position := 0;
for I := 1 to Length(mString) do
mStream.Write(mString[I] , 1);
except
Result := False;
end;
end;