PostData := TIdMultiPartFormDataStream.Create;
替换成以下试试看：
var
postData: TStrings;
begin
...
postData := TStringList.Create;
postData.Add('tag=电影') ;
...
postData.Free;
end;
在和服务端servlet通讯时，我采用 THTTPReqResp 组件，url就是完整的URL地址，如果参数值有中文，需要用HttpEncode(AnsiToUtf8(paramValue))
var
FHttpReq: THTTPReqResp;
...
function TDataSync.GetResponseContent(url: string): string;
var
strStream: TStringStream;
begin
result := '';
strStream := TStringStream.Create('',TEncoding.UTF8);
try
FHttpReq.URL := url;
FHttpReq.Execute('',strStream);
result := strStream.DataString;
except
SetLastError('无效数据包，可能网络故障！');
end;
strStream.Free;
end;
如果是上传文件，我用 TIdHttp 控件。如下：
function TDataSync.UploadFile(fileName: string; var url: string): boolean;
var
sUrl: string;
idHttp: TIdHTTP;
strStream: TStringStream;
data: TIdMultiPartFormDataStream;
begin
result := false;
if not FileExists(fileName) then exit;
data := TIdMultiPartFormDataStream.Create();
data.AddFile('attachment',fileName,GetMIMETypeFromFile(fileName));
idHttp := TIdHTTP.Create(self);
strStream := TStringStream.Create('',TEncoding.UTF8);
try
sUrl := Format('%s%s',[FWebSite,URL_UPLOADFILE]);
idHttp.Post(sUrl,data,strStream);
result := GetResponseState(strStream.DataString);
url := AnalysisUploadFileUrl(strStream.DataString);
except
end;
idHttp.Free;
strStream.Free;
data.Free;
end;
