diff --git a/src/event.c b/src/event.c
index ce165bb..20488fd 100644
--- a/src/event.c
+++ b/src/event.c
@@ -185,6 +185,25 @@ static void unmap_notify(xcb_unmap_notify_event_t *ev) {
   if (client) client_unmanage(client);
 }
 
+static void map_notify(xcb_map_notify_event_t *ev) {
+  /* 锁屏重新进入桌面后绘制 bar 内容以免 bar 不显示内容 */
+  for (monitor_t *m = wm.monitor_list; m; m = m->next) {
+    if (ev->window == m->bar_window) {
+      monitor_draw_bar(m);
+      xcb_flush(wm.xcb_conn);
+      return;
+    }
+  }
+}
+
+static void expose(xcb_expose_event_t *ev) {
+  if (ev->count > 0) return;
+
+  monitor_t *monitor = wm_get_monitor_by_window(ev->window);
+  monitor_draw_bar(monitor);
+  xcb_flush(wm.xcb_conn);
+}
+
 static void handle_xcb_event(xcb_generic_event_t *event) {
   uint8_t event_type = XCB_EVENT_RESPONSE_TYPE(event);
   const char *label = xcb_event_get_label(event_type);
@@ -202,6 +221,8 @@ static void handle_xcb_event(xcb_generic_event_t *event) {
     EVENT(XCB_KEY_RELEASE, key_press);
     EVENT(XCB_CONFIGURE_REQUEST, configure_request);
     EVENT(XCB_MAP_REQUEST, map_request);
+    EVENT(XCB_MAP_NOTIFY, map_notify);
+    EVENT(XCB_EXPOSE, expose);
     EVENT(XCB_CLIENT_MESSAGE, client_message);
     EVENT(XCB_PROPERTY_NOTIFY, property_notify);
     EVENT(XCB_UNMAP_NOTIFY, unmap_notify);
diff --git a/src/wm.c b/src/wm.c
index d95915d..b326662 100644
--- a/src/wm.c
+++ b/src/wm.c
@@ -21,7 +21,9 @@
 #include "atoms-extern.h"
 #include "atoms.h"
 #include "backtrace.h"
+#include "base.h"
 #include "buffer.h"
+#include "client.h"
 #include "color.h"
 #include "default_config.h"
 #include "event.h"
@@ -395,6 +397,26 @@ void wm_restack_clients(void) {
   xcb_flush(wm.xcb_conn);
 }
 
+static inline int intersect(area_t area, monitor_t *m) {
+  return MAX(0, MIN(area.x + area.width, m->geometry.x + m->geometry.width) -
+                  MAX(area.x, m->geometry.x)) *
+         MAX(0, MIN(area.y + area.height, m->geometry.y + m->geometry.height) -
+                  MAX(area.y, m->geometry.y));
+}
+
+monitor_t *wm_get_monitor_by_area(area_t area) {
+  monitor_t *monitor = wm.current_monitor;
+  int temp_area, max_area = 0;
+  for (monitor_t *m = wm.monitor_list; m; m = m->next) {
+    if ((temp_area = intersect(area, m)) > max_area) {
+      max_area = temp_area;
+      monitor = m;
+    }
+  }
+
+  return monitor;
+}
+
 monitor_t *wm_get_monitor_by_point(point_t point) {
   for (monitor_t *m = wm.monitor_list; m; m = m->next) {
     if (m->geometry.x <= point.x &&
@@ -405,6 +427,28 @@ monitor_t *wm_get_monitor_by_point(point_t point) {
   return wm.monitor_list;
 }
 
+monitor_t *wm_get_monitor_by_window(xcb_window_t window) {
+  if (window == wm.screen->root) {
+    xcb_query_pointer_cookie_t cookie = xcb_query_pointer(wm.xcb_conn, window);
+    xcb_query_pointer_reply_t *reply =
+      xcb_query_pointer_reply(wm.xcb_conn, cookie, nullptr);
+    if (reply) {
+      area_t area = {reply->root_x, reply->root_y, 1, 1};
+      p_delete(&reply);
+      return wm_get_monitor_by_area(area);
+    }
+  }
+
+  for (monitor_t *m = wm.monitor_list; m; m = m->next) {
+    if (window == m->bar_window) return m;
+  }
+
+  client_t *c = client_get_by_window(window);
+  if (c) return c->monitor;
+
+  return wm.current_monitor;
+}
+
 monitor_t *wm_get_next_monitor(monitor_t *monitor) {
   monitor_t *next_monitor = monitor->next;
   if (next_monitor == nullptr) next_monitor = wm.monitor_list;
diff --git a/src/wm.h b/src/wm.h
index 24c3155..b3a34f4 100644
--- a/src/wm.h
+++ b/src/wm.h
@@ -53,5 +53,7 @@ extern wm_t wm;
 void wm_restart(void);
 void wm_quit(void);
 void wm_restack_clients(void);
+monitor_t *wm_get_monitor_by_area(area_t area);
 monitor_t *wm_get_monitor_by_point(point_t point);
+monitor_t *wm_get_monitor_by_window(xcb_window_t window);
 monitor_t *wm_get_next_monitor(monitor_t *monitor);