-

mpv.net/Misc/Command.cs

@@ -226,6 +226,16 @@ namespace mpvnet
             }));
         }
 
+        public static void add_files_to_playlist(string[] args)
+        {
+            MainForm.Instance.Invoke(new Action(() => {
+                using (var d = new OpenFileDialog() { Multiselect = true })
+                    if (d.ShowDialog() == DialogResult.OK)
+                        foreach(string file in d.FileNames)
+                            mp.commandv("loadfile", file, "append");
+            }));
+        }
+
         public static void cycle_audio(string[] args)
         {
             string filePath = mp.get_property_string("path", false);

mpv.net/Resources/inputConf.txt

@@ -31,6 +31,7 @@
  Alt+a       script-message mpv.net load-audio #menu: Open > Load external audio files...
  Alt+s       script-message mpv.net load-sub   #menu: Open > Load external subtitle files...
  _           ignore                            #menu: Open > -
+ _           script-message mpv.net add-files-to-playlist #menu: Open > Add files to playlist...
  _           ignore                            #menu: Open > Recent
 
  _           ignore                 #menu: -