function TIdSocketHandle.CheckIsReadable(AMSec: Integer): Boolean;
var
ReadList: TList;
begin
if not FHandleAllocated then begin
raise EIdConnClosedGracefully.Create(RSConnectionClosedGracefully);
end;
try
ReadList := TList.Create;
{ReadList := TList.Create这句会报错}
ReadList.Add(Pointer(Handle));
Result := GStack.WSSelect(ReadList, nil, nil, AMSec) = 1;
TIdAntiFreezeBase.DoProcess(Result = False);
finally
ReadList.Free;
end;
end;
请大家帮忙看看是什么原因

应该写：
abc := TABC.Create;
try
do something...
finally
abc.Free;
end;

不应该写成：

try
abc := TABC.Create;
finally
abc.Free;
end;