Added the FEATURE-998 also to the open last file context menu.

GreenshotPlugin/Core/ExplorerHelper.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+
+namespace GreenshotPlugin.Core
+{
+	/// <summary>
+	/// Simple utility for the explorer
+	/// </summary>
+	public static class ExplorerHelper
+	{
+		/// <summary>
+		/// Open the path in the windows explorer.
+		/// If the path is a directory, it will just open the explorer with that directory.
+		/// If the path is a file, the explorer is opened with the directory and the file is selected.
+		/// </summary>
+		/// <param name="path">Path to file or directory</param>
+		public static void OpenInExplorer(string path)
+		{
+			if (path == null)
+			{
+				return;
+			}
+			try
+			{
+				// Check if path is a directory
+				if (Directory.Exists(path))
+				{
+					using (Process.Start(path))
+					{
+					}
+				}
+				// Check if path is a file
+				else if (File.Exists(path))
+				{
+					// Start the explorer process and select the file
+					using (var explorer = Process.Start("explorer.exe", $"/select,\"{path}\""))
+					{
+						explorer?.WaitForInputIdle(500);
+					}
+				}
+			}
+			catch (Exception ex)
+			{
+				// Make sure we show what we tried to open in the exception
+				ex.Data.Add("path", path);
+				throw;
+			}
+		}
+	}
+}