Tstringstream求助

[zjxsw]

s.Tstringstream.creat();
IdHTTP1.Get( 'http://xxx/xxx.* ',s);

每做一次get，s.DataString内容就会增加。
有没有方法，比如clear，清空Tstringstream？

[zjxsw]

[Quote=引用 5 楼 kye_jufei 的回复:]
嗯，這樣也可：（使用TIdhttp.get方法+Thread更好）...

[/Quote]

哈，谢了。我不是要保存到文件。我只是取得字符串，进行比较。

get好像不能直接放到字符串变量吧？

[老之]

重新创建TStringStream对象就可以清空了

[kye_jufei]

可使用try ...finally...end + Free就可以了...（舉例如下）：
1.

procedure TForm1.Button3Click(Sender: TObject);
var
  StringStream: TStringStream;
  str,strHex: string;
begin
  if Length(BytesGB18030) < 1 then Exit;

  {直接根据字节数组建立 TStringStream}
  StringStream := TStringStream.Create(BytesGB18030);
  {TStringStream.DataString 就已经是标准的 string}
  str := StringStream.DataString;

  Memo1.Lines.Add(StringStream.DataString);
  Memo1.Lines.Add(ToHex(@StringStream.Bytes[0], Length(StringStream.Bytes)));
  Memo1.Lines.Add('');
  Memo1.Lines.Add(str);
  Memo1.Lines.Add(ToHex(@str[1], ByteLength(str)));
  StringStream.Free;
end;

2.

function ComponentToStr(AComponent: TComponent): string;
var
  BinStream: TMemoryStream;
  StrStream: TStringStream;
  s: string;
begin
  BinStream := TMemoryStream.Create;
  try
    StrStream := TStringStream.Create(s);
    try
      BinStream.WriteComponent(AComponent);
      BinStream.Seek(0, soFromBeginning);
      ObjectBinaryToText(BinStream, StrStream);
      StrStream.Seek(0, soFromBeginning);
      Result := StrStream.DataString;
    finally
      StrStream.Free;
    end;
  finally
    BinStream.Free
  end;
end;

3.

function StrToComponent(const Value: string;
  Instance: TComponent): TComponent;
var
  StrStream: TStringStream;
  BinStream: TMemoryStream;
begin
  StrStream := TStringStream.Create(Value);
  try
    BinStream := TMemoryStream.Create;
    try
      ObjectTextToBinary(StrStream, BinStream);
      BinStream.Seek(0, soFromBeginning);
      Result := BinStream.ReadComponent(Instance);
    finally
      BinStream.Free;
    end;
  finally
    StrStream.Free;
  end;
end; 

[zjxsw]

只能用creat了！

在一个大循环里，用creat和free不是很费时间吗？有没有更好的思路？

[老之]

TIdHTTP.Get方法，是可以把收到的内容放到字符串或者TStringList对象里面，不一定是TStream。就算要用TStream，用TMemoryStream也比TStringStream好用

[kye_jufei]

嗯，這樣也可：（使用TIdhttp.get方法+Thread更好）...

procedure ThreadDown.Execute;
var
  str:TMemoryStream;
begin
  str:=TMemoryStream.Create;
  try TIdhttp.Get(TUrl,str);
    str.SaveToFile(TName);
    if TAuto='True' then
    ShellExecute(0,'Open',PChar(TName),nil,nil,SW_SHOW);
    str.Free;
    TIdhttp.Free;
  finally
  end;
end;