How can know length of readstring in Idtcpserver

[Zsanvs]

Hello，

We have 4G IOT adapter which can send json package to my delphi idtcpserver ， i use
Memo1.Lines.Add('receiveString-> ：' + AContext.Connection.IOHandler.Readstring(160));
but length of string is not fixed, like following 4 json packages,  length of third one is different with others, so i can't fix in IOHandler.Readstring(???)).

{"devId":"492C201010012591","msgType":"aiValueRpt","data":{"AI1":"0","AI2":"0","AI3":"0","AI4":"0"},"timestamp":"1630043052"}
{"devId":"492C201010012591","msgType":"aiValueRpt","data":{"AI1":"0","AI2":"0","AI3":"0","AI4":"0"},"timestamp":"1630043053"}
{"devId":"492C201010012591","msgType":"rs485ValueRpt","data":"0103040ADC1786B643","timestamp":"1630043053"}
{"devId":"492C201010012591","msgType":"aiValueRpt","data":{"AI1":"0","AI2":"0","AI3":"0","AI4":"0"},"timestamp":"1630043054"}


How can read these strings by idtcpserver?

Thank you!
Ike