From 582412f4dc0e2e455473ade96570f521b9999194 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Benjamin=20H=C3=B6glinger-Stelzer?= <nefarius@dhmx.at>
Date: Sat, 13 Jul 2024 17:20:18 +0200
Subject: [PATCH] Refined error handling

---
 Nefarius.Peripherals.SerialPort/CommPortException.cs | 11 +++++++++++
 Nefarius.Peripherals.SerialPort/SerialPort.cs        | 10 +++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/Nefarius.Peripherals.SerialPort/CommPortException.cs b/Nefarius.Peripherals.SerialPort/CommPortException.cs
index bb4c8e7..7be3875 100644
--- a/Nefarius.Peripherals.SerialPort/CommPortException.cs
+++ b/Nefarius.Peripherals.SerialPort/CommPortException.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.InteropServices;
 
 namespace Nefarius.Peripherals.SerialPort;
 
@@ -22,4 +23,14 @@ public class CommPortException : ApplicationException
     public CommPortException(Exception e) : base("Receive Thread Exception", e)
     {
     }
+
+    public CommPortException(string message, int error) : base(message)
+    {
+        Win32Error = error;
+    }
+
+    /// <summary>
+    ///     The Win32 error that caused the exception.
+    /// </summary>
+    public int Win32Error { get; } = Marshal.GetLastWin32Error();
 }
\ No newline at end of file
diff --git a/Nefarius.Peripherals.SerialPort/SerialPort.cs b/Nefarius.Peripherals.SerialPort/SerialPort.cs
index c51177f..3293f2e 100644
--- a/Nefarius.Peripherals.SerialPort/SerialPort.cs
+++ b/Nefarius.Peripherals.SerialPort/SerialPort.cs
@@ -70,8 +70,12 @@ public partial class SerialPort : IDisposable
         }
 
         _hPort = PInvoke.CreateFile(PortName,
-            (uint)(FILE_ACCESS_RIGHTS.FILE_GENERIC_READ | FILE_ACCESS_RIGHTS.FILE_GENERIC_WRITE), 0,
-            null, FILE_CREATION_DISPOSITION.OPEN_EXISTING, FILE_FLAGS_AND_ATTRIBUTES.FILE_FLAG_OVERLAPPED, null);
+            (uint)(FILE_ACCESS_RIGHTS.FILE_GENERIC_READ | FILE_ACCESS_RIGHTS.FILE_GENERIC_WRITE),
+            0,
+            null,
+            FILE_CREATION_DISPOSITION.OPEN_EXISTING, FILE_FLAGS_AND_ATTRIBUTES.FILE_FLAG_OVERLAPPED,
+            null
+        );
 
         if (_hPort.IsInvalid)
         {
@@ -80,7 +84,7 @@ public partial class SerialPort : IDisposable
                 return false;
             }
 
-            throw new CommPortException("Port Open Failure");
+            throw new CommPortException("Port Open Failure", Marshal.GetLastWin32Error());
         }
 
         _online = true;