diff --git a/example/applet-example-data/exampleapplet.cpp b/example/applet-example-data/exampleapplet.cpp
index 41aed9198..7421f128a 100644
--- a/example/applet-example-data/exampleapplet.cpp
+++ b/example/applet-example-data/exampleapplet.cpp
@@ -5,6 +5,7 @@
 #include "exampleapplet.h"
 
 #include "pluginfactory.h"
+#include "appletitem.h"
 
 ExampleApplet::ExampleApplet(QObject *parent)
     : DApplet(parent)
@@ -18,6 +19,17 @@ QString ExampleApplet::mainText() const
     return m_mainText;
 }
 
+void ExampleApplet::init()
+{
+    DApplet::init();
+
+    DAppletItem *root = qobject_cast<DAppletItem *>(rootObject());
+    Q_ASSERT(root);
+
+    m_mainText = QString("%1 - w:%2;h:%3").arg(m_mainText).arg(root->width()).arg(root->height());
+    Q_EMIT mainTextChanged();
+}
+
 D_APPLET_CLASS(ExampleApplet)
 
 #include "exampleapplet.moc"
diff --git a/example/applet-example-data/exampleapplet.h b/example/applet-example-data/exampleapplet.h
index 50179f9a9..9e67829c8 100644
--- a/example/applet-example-data/exampleapplet.h
+++ b/example/applet-example-data/exampleapplet.h
@@ -11,11 +11,16 @@ DS_USE_NAMESPACE
 class ExampleApplet : public DApplet
 {
     Q_OBJECT
-    Q_PROPERTY(QString mainText READ mainText CONSTANT)
+    Q_PROPERTY(QString mainText READ mainText NOTIFY mainTextChanged CONSTANT)
 public:
     explicit ExampleApplet(QObject *parent = nullptr);
 
     QString mainText() const;
+
+    virtual void init() override;
+
+Q_SIGNALS:
+    void mainTextChanged();
 private:
     QString m_mainText;
 };
diff --git a/example/panel-example/examplepanel.cpp b/example/panel-example/examplepanel.cpp
index 38c423c32..cc918d142 100644
--- a/example/panel-example/examplepanel.cpp
+++ b/example/panel-example/examplepanel.cpp
@@ -6,7 +6,6 @@
 
 #include "pluginfactory.h"
 
-
 ExamplePanel::ExamplePanel(QObject *parent)
     : DPanel(parent)
 {
@@ -20,6 +19,8 @@ void ExamplePanel::load()
 void ExamplePanel::init()
 {
     DPanel::init();
+    Q_ASSERT(rootObject());
+    Q_ASSERT(window());
 }
 
 D_APPLET_CLASS(ExamplePanel)
diff --git a/frame/applet.cpp b/frame/applet.cpp
index e67052707..419cb9b5a 100644
--- a/frame/applet.cpp
+++ b/frame/applet.cpp
@@ -48,6 +48,12 @@ DPluginMetaData DApplet::pluginMetaData() const
     return d->m_metaData;
 }
 
+QObject *DApplet::rootObject() const
+{
+    D_DC(DApplet);
+    return d->m_rootObject;
+}
+
 void DApplet::init()
 {
 }
diff --git a/frame/applet.h b/frame/applet.h
index 149f1c693..f3926e2cc 100644
--- a/frame/applet.h
+++ b/frame/applet.h
@@ -14,18 +14,22 @@ DS_BEGIN_NAMESPACE
 /**
  * @brief 插件项，单个插件实例
  */
+class DAppletItem;
 class DAppletPrivate;
 class DS_SHARE DApplet : public QObject, public DTK_CORE_NAMESPACE::DObject
 {
     Q_OBJECT
     Q_PROPERTY(QString pluginId READ pluginId CONSTANT FINAL)
+    Q_PROPERTY(QObject *rootObject READ rootObject NOTIFY rootObjectChanged)
     D_DECLARE_PRIVATE(DApplet)
+    friend class DAppletItem;
 public:
     explicit DApplet(QObject *parent = nullptr);
     virtual ~DApplet() override;
 
     void setMetaData(const DPluginMetaData &metaData);
     QString pluginId() const;
+    QObject *rootObject() const;
 
     DPluginMetaData pluginMetaData() const;
 
@@ -33,6 +37,9 @@ class DS_SHARE DApplet : public QObject, public DTK_CORE_NAMESPACE::DObject
 
     virtual void load();
 
+Q_SIGNALS:
+    void rootObjectChanged();
+
 protected:
     explicit DApplet(DAppletPrivate &dd, QObject *parent = nullptr);
 };
diff --git a/frame/appletitem.cpp b/frame/appletitem.cpp
index baa98cc36..7c658ad78 100644
--- a/frame/appletitem.cpp
+++ b/frame/appletitem.cpp
@@ -4,6 +4,7 @@
 
 #include "appletitem.h"
 #include "private/appletitem_p.h"
+#include "private/applet_p.h"
 #include "applet.h"
 #include "qmlengine.h"
 
@@ -41,7 +42,7 @@ DAppletItem *DAppletItem::itemForApplet(DApplet *applet)
     if (it != g_appletItems.constEnd())
         return it.value();
 
-    QScopedPointer<DQmlEngine> engine(new DQmlEngine(applet, applet));
+    std::unique_ptr<DQmlEngine> engine(new DQmlEngine(applet, applet));
 
     auto rootObject = engine->beginCreate();
     if (!rootObject) {
@@ -55,10 +56,11 @@ DAppletItem *DAppletItem::itemForApplet(DApplet *applet)
     }
 
     item->d_func()->m_applet = applet;
-    item->d_func()->m_engine = engine.take();
+    item->d_func()->m_engine = engine.release();
     g_appletItems[applet] = item;
 
     item->d_func()->m_engine->completeCreate();
+    applet->d_func()->setRootObject(item);
 
     return item;
 }
diff --git a/frame/panel.cpp b/frame/panel.cpp
index ce8727e49..14b0fc90a 100644
--- a/frame/panel.cpp
+++ b/frame/panel.cpp
@@ -29,7 +29,7 @@ DPanel::~DPanel()
 QQuickWindow *DPanel::window() const
 {
     D_DC(DPanel);
-    return d->m_window;
+    return qobject_cast<QQuickWindow *>(d->m_rootObject);
 }
 
 void DPanel::load()
@@ -51,8 +51,8 @@ void DPanel::init()
 
     auto window = qobject_cast<QQuickWindow *>(rootObject);
     if (window) {
-        d->m_window = window;
-        d->m_window->setProperty("_ds_window_applet", QVariant::fromValue(applet));
+        applet->d_func()->setRootObject(window);
+        d->m_rootObject->setProperty("_ds_window_applet", QVariant::fromValue(applet));
     }
 
     DContainment::init();
diff --git a/frame/private/applet_p.h b/frame/private/applet_p.h
index dfdccb24a..95f5b39ad 100644
--- a/frame/private/applet_p.h
+++ b/frame/private/applet_p.h
@@ -22,6 +22,15 @@ class DAppletPrivate : public DTK_CORE_NAMESPACE::DObjectPrivate
     }
 
     DPluginMetaData m_metaData;
+    QObject *m_rootObject{nullptr};
+    void setRootObject(QObject *root)
+    {
+        if (m_rootObject == root)
+            return;
+        m_rootObject = root;
+        D_Q(DApplet);
+        Q_EMIT q->rootObjectChanged();
+    }
 
     D_DECLARE_PUBLIC(DApplet);
 };
diff --git a/frame/private/panel_p.h b/frame/private/panel_p.h
index bfbbde690..018e2c015 100644
--- a/frame/private/panel_p.h
+++ b/frame/private/panel_p.h
@@ -25,8 +25,6 @@ class DPanelPrivate : public DContainmentPrivate
 
     void initDciSearchPaths();
 
-    QQuickWindow *m_window = nullptr;
-
     D_DECLARE_PUBLIC(DPanel)
 };
 
diff --git a/frame/qmlengine.cpp b/frame/qmlengine.cpp
index 988679d3b..9b346e5db 100644
--- a/frame/qmlengine.cpp
+++ b/frame/qmlengine.cpp
@@ -77,7 +77,7 @@ DQmlEngine::~DQmlEngine()
 QObject *DQmlEngine::beginCreate()
 {
     D_D(DQmlEngine);
-    QScopedPointer<QQmlComponent> component(new QQmlComponent(engine(), this));
+    std::unique_ptr<QQmlComponent> component(new QQmlComponent(engine(), this));
     const QString url = d->appletUrl();
     if (url.isEmpty())
         return nullptr;
@@ -91,7 +91,7 @@ QObject *DQmlEngine::beginCreate()
     auto object = component->beginCreate(context);
     d->m_context = context;
     d->m_rootObject = object;
-    d->m_component = component.take();
+    d->m_component = component.release();
     return object;
 }