diff --git a/example/qml/page/T_OpenGL.qml b/example/qml/page/T_OpenGL.qml
index 8582fb3e..c39b4869 100644
--- a/example/qml/page/T_OpenGL.qml
+++ b/example/qml/page/T_OpenGL.qml
@@ -10,13 +10,10 @@ FluContentPage{
 
     title: qsTr("OpenGL")
 
-
     FluFrame{
         anchors.fill: parent
-
         OpenGLItem{
-            width: 320
-            height: 480
+            anchors.fill: parent
             SequentialAnimation on t {
                 NumberAnimation { to: 1; duration: 2500; easing.type: Easing.InQuad }
                 NumberAnimation { to: 0; duration: 2500; easing.type: Easing.OutQuad }
@@ -24,9 +21,6 @@ FluContentPage{
                 running: true
             }
         }
-
     }
 
-
-
 }
diff --git a/example/src/component/OpenGLItem.cpp b/example/src/component/OpenGLItem.cpp
index 60c6bdee..58e86d78 100644
--- a/example/src/component/OpenGLItem.cpp
+++ b/example/src/component/OpenGLItem.cpp
@@ -47,7 +47,7 @@ QOpenGLFramebufferObject *FBORenderer::createFramebufferObject(const QSize &size
 }
 
 void FBORenderer::render() {
-    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
     glEnable(GL_DEPTH_TEST);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
     program.bind();
diff --git a/example/src/component/OpenGLItem.h b/example/src/component/OpenGLItem.h
index 4b9da909..d1570c7f 100644
--- a/example/src/component/OpenGLItem.h
+++ b/example/src/component/OpenGLItem.h
@@ -12,11 +12,11 @@ Q_OBJECT
 public:
     explicit OpenGLItem(QQuickItem *parent = nullptr);
 
-    QQuickFramebufferObject::Renderer *createRenderer() const override;
+    [[nodiscard]] QQuickFramebufferObject::Renderer *createRenderer() const override;
 
     void timerEvent(QTimerEvent *) override;
 
-    qreal t() const { return m_t; }
+    [[nodiscard]] qreal t() const { return m_t; }
 
     void setT(qreal t);
 
diff --git a/src/FluTreeModel.h b/src/FluTreeModel.h
index 7765a66f..07eb6ed6 100644
--- a/src/FluTreeModel.h
+++ b/src/FluTreeModel.h
@@ -19,10 +19,14 @@ Q_OBJECT
 public:
     explicit FluTreeNode(QObject *parent = nullptr);
 
-    Q_INVOKABLE int depth() const { return _depth; };
-    Q_INVOKABLE bool isExpanded() const { return _isExpanded; };
-    Q_INVOKABLE QVariantMap data() const { return _data; };
-    Q_INVOKABLE bool hasChildren() const { return !_children.isEmpty(); };
+    [[nodiscard]] Q_INVOKABLE int depth() const { return _depth; };
+
+    [[nodiscard]] Q_INVOKABLE bool isExpanded() const { return _isExpanded; };
+
+    [[nodiscard]] Q_INVOKABLE QVariantMap data() const { return _data; };
+
+    [[nodiscard]] Q_INVOKABLE bool hasChildren() const { return !_children.isEmpty(); };
+
     Q_INVOKABLE bool hasNextNodeByIndex(int index) {
         FluTreeNode *p = this;
         for (int i = 0; i <= _depth - index - 1; i++) {
@@ -34,7 +38,7 @@ public:
         return true;
     }
 
-    Q_INVOKABLE bool checked() const {
+    [[nodiscard]] Q_INVOKABLE bool checked() const {
         if (!hasChildren()) {
             return _checked;
         }
@@ -46,6 +50,7 @@ public:
         }
         return true;
     };
+    
     Q_INVOKABLE bool hideLineFooter() {
         if (_parent) {
             auto childIndex = _parent->_children.indexOf(this);
@@ -60,7 +65,7 @@ public:
         return false;
     };
 
-    bool isShown() const {
+    [[nodiscard]] bool isShown() const {
         auto p = _parent;
         while (p) {
             if (!p->_isExpanded) {
@@ -96,17 +101,17 @@ public:
 
     explicit FluTreeModel(QObject *parent = nullptr);
 
-    int rowCount(const QModelIndex &parent = {}) const override;
+    [[nodiscard]] int rowCount(const QModelIndex &parent = {}) const override;
 
-    int columnCount(const QModelIndex &parent = {}) const override;
+    [[nodiscard]] int columnCount(const QModelIndex &parent = {}) const override;
 
-    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    [[nodiscard]] QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
 
-    QHash<int, QByteArray> roleNames() const override;
+    [[nodiscard]] QHash<int, QByteArray> roleNames() const override;
 
-    QModelIndex parent(const QModelIndex &child) const override;
+    [[nodiscard]] QModelIndex parent(const QModelIndex &child) const override;
 
-    QModelIndex index(int row, int column, const QModelIndex &parent = {}) const override;
+    [[nodiscard]] QModelIndex index(int row, int column, const QModelIndex &parent = {}) const override;
 
     Q_INVOKABLE void removeRows(int row, int count);