检测文件是否是ASCII文件

check if a file has an ASCII format? function isAscii(NomeFile: string): Boolean;
const
SETT = 2048;
var
i: Integer;
F: file;
a: Boolean;
TotSize, IncSize, ReadSize: Integer;
c: array[0..Sett] of Byte;
begin
if FileExists(NomeFile) then
begin
{$I-}
AssignFile(F, NomeFile);
Reset(F, 1);
TotSize := FileSize(F);
IncSize := 0;
a := True;
while (IncSize < TotSize) and (a = True) do
begin
ReadSize := SETT;
if IncSize + ReadSize > TotSize then ReadSize := TotSize - IncSize;
IncSize := IncSize + ReadSize;
BlockRead(F, c, ReadSize);
// Iterate
for i := 0 to ReadSize - 1 do
if (c < 32) and (not (c in [9, 10, 13, 26])) then a := False;
end; { while }
CloseFile(F);
{$I+}
if IOResult <> 0 then Result := False
else
Result := a;
end;
end;