关于获得qt tableview行数等信息

//mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QModelIndex>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

public slots:
void get_data(QModelIndex data);

private:
Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QStandardItemModel>

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);

QStandardItemModel *model =new QStandardItemModel();

ui->tableView->setColumnWidth(0,145);
ui->tableView->setColumnWidth(1,130);
//ui->tableView->setColumnWidth(2,70);

model->setColumnCount(2);
model->setHeaderData(0,Qt::Horizontal,tr("日期"));
model->setHeaderData(1,Qt::Horizontal,tr("温度记录"));

model->setItem(0,0,new QStandardItem("2015-07-30"));
model->setItem(0,1,new QStandardItem(tr("31℃")));

model->setItem(1,0,new QStandardItem("2015-07-31"));
model->setItem(1,1,new QStandardItem(tr("32℃")));

ui->tableView->setModel(model);

connect(ui->tableView,SIGNAL(clicked(QModelIndex)),this,SLOT(get_data(QModelIndex)));
}

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

void MainWindow::get_data(QModelIndex data)
{
ui->lineEdit->setText(QString::number(data.row()));
}