diff --git a/include/nana/gui/programming_interface.hpp b/include/nana/gui/programming_interface.hpp
index 0a1d55d8..4d1931dc 100644
--- a/include/nana/gui/programming_interface.hpp
+++ b/include/nana/gui/programming_interface.hpp
@@ -106,6 +106,8 @@ namespace API
 		 * This function will copy the drawer surface into system window after the event process finished.
 		 */
 		void lazy_refresh();
+
+		void draw_shortkey_underline(paint::graphics&, const std::string& text, wchar_t shortkey, std::size_t shortkey_position, const point& text_pos, const color&);
 	}//end namespace dev
 
 	/// Returns the widget pointer of the specified window.
diff --git a/source/gui/programming_interface.cpp b/source/gui/programming_interface.cpp
index 6f91756e..6121d95d 100644
--- a/source/gui/programming_interface.cpp
+++ b/source/gui/programming_interface.cpp
@@ -365,6 +365,24 @@ namespace API
 		{
 			restrict::bedrock.thread_context_lazy_refresh();
 		}
+
+		void draw_shortkey_underline(paint::graphics& graph, const std::string& text, wchar_t shortkey, std::size_t shortkey_position, const point& text_pos, const color& line_color)
+		{
+			if (shortkey)
+			{
+				auto off_x = (shortkey_position ? graph.text_extent_size(text.c_str(), shortkey_position).width : 0);
+				auto key_px = static_cast<int>(graph.text_extent_size(&shortkey, 1).width);
+
+				unsigned ascent, descent, inleading;
+				graph.text_metrics(ascent, descent, inleading);
+
+				int x = text_pos.x + static_cast<int>(off_x);
+				int y = text_pos.y + static_cast<int>(ascent + 2);
+
+				graph.line({ x, y }, {x + key_px - 1, y}, line_color);
+
+			}
+		}
 	}//end namespace dev
 
 
diff --git a/source/gui/widgets/button.cpp b/source/gui/widgets/button.cpp
index 01de4f7c..a01d001b 100644
--- a/source/gui/widgets/button.cpp
+++ b/source/gui/widgets/button.cpp
@@ -34,12 +34,7 @@ namespace nana{	namespace drawerbase
 					return{};
 
 				wchar_t shortkey;
-				std::string::size_type shortkey_pos;
-				
-				auto str = to_wstring(API::transform_shortkey_text(trigger_->wdg_->caption(), shortkey, &shortkey_pos));
-				auto text_sz = graph.text_extent_size(str);
-
-				return size{ text_sz.width, text_sz.height };
+				return graph.text_extent_size(API::transform_shortkey_text(trigger_->wdg_->caption(), shortkey, nullptr));
 			}
 
 			size extension() const override
@@ -261,28 +256,15 @@ namespace nana{	namespace drawerbase
 						++pos.y;
 					}
 
-					graph.palette(true, attr_.focus_color && attr_.focused ? ::nana::color(colors::blue) : attr_.fgcolor);
+					auto text_color = (attr_.focus_color && attr_.focused ? ::nana::color(colors::blue) : attr_.fgcolor);
+					graph.palette(true, text_color);
 
 					if (attr_.omitted)
 						tr.render(pos, txtptr, txtlen, omitted_pixels, true);
 					else
 						graph.bidi_string(pos, txtptr, txtlen);
 
-					if(shortkey)
-					{
-						unsigned off_w = (shortkey_pos ? graph.text_extent_size(mbstr.c_str(), shortkey_pos).width : 0);
-
-						wchar_t keystr[2] = {nana::utf::char_at(mbstr.c_str() + shortkey_pos, 0, 0), 0};
-						auto shortkey_size = graph.text_extent_size(keystr, 1);
-
-						unsigned ascent, descent, inleading;
-						graph.text_metrics(ascent, descent, inleading);
-
-						pos.x += off_w;
-						pos.y += static_cast<int>(ascent + 2);
-
-						graph.line(pos, point{ pos.x + static_cast<int>(shortkey_size.width) - 1, pos.y }, colors::black);
-					}
+					API::dev::draw_shortkey_underline(graph, mbstr, shortkey, shortkey_pos, pos, text_color);
 				}
 				else
 				{
diff --git a/source/gui/widgets/menu.cpp b/source/gui/widgets/menu.cpp
index bdf2cba1..36dbb7de 100644
--- a/source/gui/widgets/menu.cpp
+++ b/source/gui/widgets/menu.cpp
@@ -441,23 +441,9 @@ namespace nana
 
 						renderer->item_text(graph, nana::point(item_r.x + 40, item_r.y + text_top_off), text, strpixels, attr);
 
-						if (hotkey)
-						{
-							item_ptr->hotkey = hotkey;
-							if (item_ptr->flags.enabled)
-							{
-								auto off_px = (hotkey_pos ? graph.text_extent_size(text.c_str(), hotkey_pos).width : 0);
-								auto hotkey_px = graph.text_extent_size(text.c_str() + hotkey_pos, 1).width;
-
-								unsigned ascent, descent, inleading;
-								graph.text_metrics(ascent, descent, inleading);
-
-								int x = item_r.x + 40 + off_px;
-								int y = item_r.y + text_top_off + ascent + 1;
-
-								graph_->line({ x, y }, { x + static_cast<int>(hotkey_px)-1, y }, colors::black);
-							}
-						}
+						item_ptr->hotkey = hotkey;
+						if (hotkey && item_ptr->flags.enabled)
+								API::dev::draw_shortkey_underline(*graph_, text, hotkey, hotkey_pos, {item_r.x + 40, item_r.y + text_top_off}, colors::black);
 
 						if (item_ptr->linked.menu_ptr)
 							renderer->sub_arrow(graph, nana::point(graph_->width() - 20, item_r.y), item_h_px, attr);
diff --git a/source/gui/widgets/menubar.cpp b/source/gui/widgets/menubar.cpp
index 0fc114b9..4ed24c67 100644
--- a/source/gui/widgets/menubar.cpp
+++ b/source/gui/widgets/menubar.cpp
@@ -212,17 +212,7 @@ namespace nana
 						int text_top_off = (item_s.height - text_s.height) / 2;
 						ird.caption({ item_pos.x + 8, item_pos.y + text_top_off }, to_nstring(text));
 
-						if (hotkey)
-						{
-							unsigned off_w = (hotkey_pos ? graph.text_extent_size(text.c_str(), hotkey_pos).width : 0);
-							auto hotkey_size = graph.text_extent_size(nana::to_wstring(text.c_str() + hotkey_pos), 1);
-
-							unsigned ascent, descent, inleading;
-							graph.text_metrics(ascent, descent, inleading);
-							int x = item_pos.x + 8 + off_w;
-							int y = item_pos.y + text_top_off + ascent + 1;
-							graph.line({ x, y }, { x + static_cast<int>(hotkey_size.width) - 1, y }, ird.scheme_ptr()->text_fgcolor);
-						}
+						API::dev::draw_shortkey_underline(graph, text, hotkey, hotkey_pos, { item_pos.x + 8, item_pos.y + text_top_off }, ird.scheme_ptr()->text_fgcolor);
 
 						item_pos.x += i->size.width;
 						++index;