现在做的项目要兼容win10平板，加载网页的控件qwebview不响应触屏,在下拉控件qcombobox下拉时qwebview能响应一次,是什么原因呢

#ifndef WEBVIEWTEST001_H
#define WEBVIEWTEST001_H

#include <QtWebKitWidgets/QWebView>
#include <QtWebKitWidgets/QWebFrame>

class WebViewTest001 : public QWebView
{
    Q_OBJECT

public:
    WebViewTest001(QWidget *parent = 0);
    ~WebViewTest001();

 
protected:  
    bool eventFilter(QObject *obj, QEvent *ev);
};

#endif // WEBVIEWTEST001_H
#include "webviewtest001.h"
#include "qcoreevent.h"
#include "qevent.h"
#include "QtWebKitWidgets\QWebFrame"
#include <QMessageBox>
#ifdef _DEBUG
#pragma comment(lib,"Qt5Widgetsd.lib")
#pragma comment(lib,"Qt5WebKitWidgetsd.lib")
#pragma comment(lib, "Qt5WebKitd.lib")
#else
#pragma comment(lib,"Qt5Widgets.lib")
#pragma comment(lib,"Qt5WebKitWidgets.lib")
#pragma comment(lib, "Qt5WebKit.lib")
#endif
WebViewTest001::WebViewTest001(QWidget *parent)
    : QWebView(parent)
{

    installEventFilter(this);  

    // For WebPage  
    page()->installEventFilter(this);  

    // For WebFrame   
    page()->mainFrame()->installEventFilter(this);  
}

WebViewTest001::~WebViewTest001()
{

}
bool WebViewTest001::eventFilter(QObject *obj, QEvent *ev)  
{  


   

    if (ev->type() == QEvent::TouchBegin)
    {
        //QMessageBox::information(this, QStringLiteral("TouchBegin"), QStringLiteral("TouchBegin"));
    }
    if (ev->type() == QEvent::TouchUpdate)
    {
        //QMessageBox::information(this, QStringLiteral("TouchUpdate"), QStringLiteral("TouchUpdate"));
    }
    if (ev->type() == QEvent::TouchEnd)
    {
        //QMessageBox::information(this, QStringLiteral("TouchEnd"), QStringLiteral("TouchEnd"));
        //QDesktopServices::openUrl(url);
    }
   
    QWebView::eventFilter(obj,ev);
    return false;  
}  
#include "webviewtest001.h"
#include <QtWidgets/QApplication>
#include <QComboBox>
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    WebViewTest001 w;
    w.setWindowFlags(Qt::FramelessWindowHint);  

    w.setGeometry(0,0,1280,720);  
   
    w.load(QUrl("http://202.108.22.5:80/"));//百度
    QComboBox cb(&w);
    cb.addItem(QString::fromLocal8Bit("111"));
    cb.addItem(QString::fromLocal8Bit("222"));
    cb.addItem(QString::fromLocal8Bit("333"));
    cb.show();
    //cb.showPopup();
    w.show();
    return a.exec();
}
现在做的项目要兼容win10平板，加载网页的控件qwebview不响应触屏,在下拉控件qcombobox下拉时qwebview能响应一次,是什么原因呢