System.ArgumentOutOfRangeException
StartIndex 不能小于 0。
参数名: startIndex
   在 System.String.Substring(Int32 startIndex, Int32 length)
   在 VerionChecker.OnDataReceived(Object sender, SerialDataReceivedEventArgs e) 位置 D:\BitBucket\rm_assistant_vs2017\RmAssistant\Tello\Scripts\VerionChecker.cs:行号 150
   在 RJCP.IO.Ports.SerialPortStream.OnDataReceived(Object sender, SerialDataReceivedEventArgs args) 位置 c:\Users\jcurl\Documents\Programming\HELIOS\serialportstream\code\SerialPortStream.cs:行号 1801
   在 RJCP.IO.Ports.SerialPortStream.HandleEvent(Object state) 位置 c:\Users\jcurl\Documents\Programming\HELIOS\serialportstream\code\SerialPortStream.cs:行号 1897
   在 System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   在 System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   在 System.Threading.ThreadPoolWorkQueue.Dispatch()
