QT对话框 获取文件名和后缀

文件得主要目录如下图：

再mainwindow.ui中只加了一个pushbutton

dialog.cpp中没有任何操作 

最后付下主要代码：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "ui_dialog.h"
#include <QFile>
#include <QFileDialog>
#include <QMessageBox>
#include <QDebug>
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_pushButton_clicked()
{
    QString fileFull, fileName, filePath,fileSuffix;
    QFileInfo fileinfo;
    fileFull =QFileDialog::getOpenFileName(this,tr("file"),"/",tr("text(*.txt)"));

    //fileFull = E:\QtCode\newExample\myTry\新建文本文档.txt
    //获取文件信息
    fileinfo = QFileInfo(fileFull);
    //fileinfo = E:\QtCode\newExample\myTry\新建文本文档.txt
    //获取文件名字
    fileName = fileinfo.fileName();
    //fileName = 新建文本文档.txt
    //获取文件后缀
    fileSuffix = fileinfo.suffix();
    //fileSuffix = txt
    //获取文件绝对路径
    filePath = fileinfo.absolutePath();
    if(!fileFull.isNull())
    {
       QFile file(fileFull);
       if(!file.open(QFile::ReadOnly | QFile::Text))
        {
            QMessageBox::warning(this,tr("Error"),tr("read file 
error:&1").arg(file.errorString()));
            return;
        }
            QTextStream in(&file);
            QApplication::setOverrideCursor(Qt::WaitCursor);
            dialog = new Dialog(this);
            dialog->ui->lineEdit->setText(fileFull);
            dialog->ui->lineEdit_2->setText(fileName);
            dialog->ui->textEdit->setPlainText(in.readAll());
            QApplication::restoreOverrideCursor();

            dialog->show();

    }
    else
    {
       qDebug()<<"cancel";
    }

//  FileDialog::getOpenFileName(this,
//  tr("Open File"),
//  "/",

//  tr("All Files (*.*)"));

// QDesktopServices::openUrl(QUrl::fromLocalFile(QFileInfo(fileName).
}