C＃强制要触发SerialPort.DataReceived事件

Question

Like many people, I'm having issues with the DataReceived event not firing.

After working with it, I wrapped my handling processes under the the BytesToRead count, so if I miss a fire, I can pick up where I left off. Seemed like it would fix all my issues.

The problem is, sometimes it doesn't trigger even once. Depending on the packet being sent back, this could be absolutely critical, forcing me to restart the application and the setup process because it relies on being able to process a response.

Reading through some of the responses to similar questions hasn't gotten me any closer to guaranteeing that the event will fire at minimum requirements. Microsoft mentions the issue with DataReceived not being guaranteed to fire for every byte, but I noticed this above:

The DataReceived event is also raised if an Eof character is received, regardless of the number of bytes in the internal input buffer and the value of the ReceivedBytesThreshold property.

So my question is, can I force an EOF character through my serial connection to force the event to fire? What would this character be, 0x1A?

If I can't force an EOF character through serial, what would my options be? My first thought was maybe create a Task to keep a watch for the event triggering, and if it doesn't trigger, to trigger the actions through the Task.

Answer 1

So I was able to fix my issues, coming out a little wiser.

From my observations, the ReadBytesThreshold plays a critical part in how effective the event actually is. When the threshold is set too low, the serial port has a tendency to get itself confused, and will eventually throw up its hands and give up.

Setting this closer to the size of my expected data coming in appeared to help ease the burden enough to make the reading fairly consistent.

I didn't test my idea of using a Task, but reading further online appeared to answer my question about using 0x1A : from what I noticed, it will trigger if it receives this character (at least on a Windows machine).