sr:string;
//把你的流转字符串
stringstream:=TStringStream.Create(sr);
self.IdscrreenHTTP.Post('http://127.0.0.1:5555',stringstream);

服务器端接收的值在这里
ARequestInfo.FormParams

//流到字符串
function StreamToString(AStream: TStream): string;
begin
if AStream.Size = 0 then
Result := ''
else
begin
setlength(Result, AStream.Size);
AStream.Position := 0;
AStream.Read(Result[1], AStream.Size);
end;
end;

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