diff --git a/src/UserInterface/Button/letter_classify_button.cpp b/src/UserInterface/Button/letter_classify_button.cpp
index 6577384..47cd21f 100755
--- a/src/UserInterface/Button/letter_classify_button.cpp
+++ b/src/UserInterface/Button/letter_classify_button.cpp
@@ -28,16 +28,7 @@ LetterClassifyButton::LetterClassifyButton(QWidget *parent,
 {
     this->setFlat(true);
     m_letter = letter;
-//    if (m_fullscreen) {
-//        QFont font;
-//        font.setPixelSize(Style::LeftLetterFontSize);
-//        this->setFont(font);
-//        QPalette pe = this->palette();
-//        pe.setColor(QPalette::ButtonText, Qt::white);
-//        this->setPalette(pe);
-//    }
-
-//    this->setText(letter);
+    m_tooltip  = new LetterToolTip(this);
     this->setFocusPolicy(Qt::NoFocus);
     this->setCheckable(true);
     this->setStyleSheet("padding: 0px;");
@@ -147,16 +138,10 @@ void LetterClassifyButton::enterEvent(QEvent *e)
     Q_UNUSED(e);
 
     if (m_fullscreen) {
-        //        QFont font;
-        //        font.setPixelSize(Style::LeftLetterFontSize*3);
-        //        this->setFont(font);
-        //        this->setFixedSize(Style::LeftLetterBtnHeight*2,Style::LeftLetterBtnHeight*2);
-        tooltip  = new LetterToolTip();
         QPoint oPoint = this->mapToGlobal(QPoint(this->rect().x() + 35, this->rect().y() - 10));
-        tooltip->setText(m_letter);
-        tooltip->raise();
-        tooltip->move(oPoint);
-        tooltip->show();
+        m_tooltip->setText(m_letter);
+        m_tooltip->move(oPoint);
+        m_tooltip->show();
     }
 }
 
@@ -169,9 +154,7 @@ void LetterClassifyButton::leaveEvent(QEvent *e)
         font.setPixelSize(Style::m_leftLetterFontSize);
         this->setFont(font);
         this->setFixedSize(Style::m_leftLetterBtnHeight, Style::m_leftLetterBtnHeight);
-        tooltip->close();
-        delete tooltip;
-        tooltip = nullptr;
+        m_tooltip->hide();
     }
 }
 
diff --git a/src/UserInterface/Button/letter_classify_button.h b/src/UserInterface/Button/letter_classify_button.h
index fded3eb..277fab8 100755
--- a/src/UserInterface/Button/letter_classify_button.h
+++ b/src/UserInterface/Button/letter_classify_button.h
@@ -37,7 +37,7 @@ public:
     QString m_letter = QString();
 private:
     bool m_fullscreen = false;
-    LetterToolTip *tooltip = nullptr;
+    LetterToolTip *m_tooltip = nullptr;
 
 protected:
     void enterEvent(QEvent *e);
diff --git a/src/UserInterface/Other/lettertooltip.cpp b/src/UserInterface/Other/lettertooltip.cpp
index 030e544..00a28db 100755
--- a/src/UserInterface/Other/lettertooltip.cpp
+++ b/src/UserInterface/Other/lettertooltip.cpp
@@ -21,9 +21,9 @@
 #include <QHBoxLayout>
 
 LetterToolTip::LetterToolTip(QWidget *parent):
-    QDialog(parent)
+    QWidget(parent)
 {
-    this->setWindowFlags(/*Qt::FramelessWindowHint *//*| */Qt::X11BypassWindowManagerHint);
+    this->setWindowFlag(Qt::ToolTip);
     this->setAttribute(Qt::WA_TranslucentBackground, true);
     this->setContentsMargins(0, 0, 0, 0);
     this->setAutoFillBackground(false);
diff --git a/src/UserInterface/Other/lettertooltip.h b/src/UserInterface/Other/lettertooltip.h
index 81c0411..854e69f 100755
--- a/src/UserInterface/Other/lettertooltip.h
+++ b/src/UserInterface/Other/lettertooltip.h
@@ -17,10 +17,10 @@
 
 #ifndef LETTERTOOLTIP_H
 #define LETTERTOOLTIP_H
-#include <QDialog>
 #include <QLabel>
+#include <QWidget>
 
-class LetterToolTip : public QDialog
+class LetterToolTip : public QWidget
 {
     Q_OBJECT
 public: