diff --git a/examples/dev.html b/examples/dev.html
index 7a11279b2..975879916 100644
--- a/examples/dev.html
+++ b/examples/dev.html
@@ -20,34 +20,53 @@
             }
         },
         setup: function () {
-            var layout;
+            var list, count = 0;
             return function () {
                 return {
-                    type: "bi.left",
+                    type: "bi.vertical",
                     items: [{
-                        type: "bi.button",
-                        text: "点击",
-                        handler: function () {
-                            layout.populate([{
-                                type: "bi.label",
-                                key: "1",
-                                text: 1
-                            }, {
+                        type: "bi.virtual_group",
+                        height: 100,
+                        ref: function (_ref) {
+                            list = _ref;
+                        },
+                        items: BI.range(10).map(function (item, i) {
+                            var r = {
                                 type: "bi.label",
-                                key: "123",
-                                text: "start"
-                            }])
-                        }
+                                text: item,
+                                // 指定key后，会根据key值进行前后两次数据对比，否则会根据数组索引进行数据对比
+                                key: item,
+                                cls: "bi-border"
+                            };
+                            if (i === 9) {
+                                r.width = "fill";
+                                r.key = "唯一的标识";
+                            }
+                            return r;
+                        }),
+                        layouts: [{
+                            type: "bi.inline",
+                            tgap: 10,
+                            lgap: 10
+                        }]
                     }, {
-                        type: "bi.left",
-                        lgap: 10,
-                        items: [{
-                            type: "bi.label",
-                            key: "123",
-                            text: "start"
-                        }],
-                        ref: function (_ref) {
-                            layout = _ref;
+                        type: "bi.button",
+                        text: "点击删除第一个元素",
+                        handler: function () {
+                            count++;
+                            list.populate(BI.range(10 - count).map(function (i) {
+                                var r = {
+                                    type: "bi.label",
+                                    text: i + count,
+                                    key: i + count,
+                                    cls: "bi-border"
+                                };
+                                if (i + count === 9) {
+                                    r.width = "fill";
+                                    r.key = "唯一的标识";
+                                }
+                                return r;
+                            }));
                         }
                     }]
                 };
diff --git a/src/core/wrapper/layout.js b/src/core/wrapper/layout.js
index d6634e328..0bde292a7 100644
--- a/src/core/wrapper/layout.js
+++ b/src/core/wrapper/layout.js
@@ -551,9 +551,11 @@ BI.Layout = BI.inherit(BI.Widget, {
                 c.destroy();
             });
             this._children = {};
+            this._isMounted = false;
         }
         this.options.items = opt.items;
         this.stroke(opt.items);
+        this._mount();
     },
 
     update: function (opt) {