diff --git a/Bootstrap.Client/wwwroot/lib/longbow-select/longbow-select.js b/Bootstrap.Client/wwwroot/lib/longbow-select/longbow-select.js
index 3ca77918..6001c350 100644
--- a/Bootstrap.Client/wwwroot/lib/longbow-select/longbow-select.js
+++ b/Bootstrap.Client/wwwroot/lib/longbow-select/longbow-select.js
@@ -149,15 +149,17 @@
         // see https://gitee.com/LongbowEnterprise/longbow-select/issues/IZ3BR?from=project-issue
         this.$input.attr('value', '').removeClass('is-valid is-invalid');
         this.$menus.html('');
+        var $activeItem = null;
         $.each(value, function (index) {
             var $item = $('<a class="dropdown-item" href="#" data-val="' + this.value + '">' + this.text + '</a>');
             that.$menus.append($item);
             if (this.selected === true || this.value === oldValue || index === 0 || this.value === that.$element.attr('data-default-val')) {
                 that.$input.attr('value', this.text);
                 that.$element.val(this.value).attr('data-text', this.text);
-                $item.addClass('active');
+                $activeItem = $item;
             }
         });
+        if ($activeItem !== null) $activeItem.addClass('active');
 
         this.source = value;
     };
diff --git a/Bootstrap.Client/wwwroot/lib/longbow/longbow.common.js b/Bootstrap.Client/wwwroot/lib/longbow/longbow.common.js
index f200abe3..4a6a3632 100644
--- a/Bootstrap.Client/wwwroot/lib/longbow/longbow.common.js
+++ b/Bootstrap.Client/wwwroot/lib/longbow/longbow.common.js
@@ -238,7 +238,9 @@
         footer: function (options) {
             var op = $.extend({ header: "header", content: "body > section:first", ele: 'footer' }, options);
             var $ele = $(op.ele);
-            return $(op.header).outerHeight() + $(op.content).outerHeight() + $ele.outerHeight() > $(window).height() ? $ele.removeClass('position-fixed') : $ele.addClass('position-fixed');
+
+            // 增加 1px 修复 IE11 下由于小数点导致页脚消失bug
+            return $(op.header).outerHeight() + $(op.content).outerHeight() + $ele.outerHeight() > $(window).height() + 1 ? $ele.removeClass('position-fixed') : $ele.addClass('position-fixed');
         },
         formatUrl: function (url) {
             if (!url) return url;