2.QT字符串及一些基本操作

• mainwindow.h

  #ifndef MAINWINDOW_H
  #define MAINWINDOW_H
  
  #include <QMainWindow>
  
  namespace Ui {
  class MainWindow;
  }
  
  class MainWindow : public QMainWindow
  {
      Q_OBJECT
  
  public:
      explicit MainWindow(QWidget *parent = 0);
      ~MainWindow();
  
  private slots:
  19     void on_pushButton_clicked();
  20 
  21     void on_pushButton_2_clicked();
  
  private:
      Ui::MainWindow *ui;
  };
  
  #endif // MAINWINDOW_H

• mainwindow.cpp

  #include "mainwindow.h"
  #include "ui_mainwindow.h"
  #include <QDebug>
  
  MainWindow::MainWindow(QWidget *parent) :
      QMainWindow(parent),
      ui(new Ui::MainWindow)
  {
      ui->setupUi(this);
  }
  
  MainWindow::~MainWindow()
  {
      delete ui;
  }
  
  void MainWindow::on_pushButton_clicked()
  {
  19     QString qstr1;
  20     QString qstr2;
  21     qstr1 = ui->lineEdit->text();
  22     qstr2 = ui->lineEdit_2->text();
  23     QString qstr3 ;
  24    // qstr3 = qstr1 + qstr2
  25     qstr3.sprintf("%s%d%s","123",45,"abc");
  26     qDebug() << qstr3 << endl;
  27     ui->textEdit->setText(qstr3);
  }
  
  30 void MainWindow::on_pushButton_2_clicked()
  31 {
  32     QString qstr3=QString("%1 is %2").arg("hello").arg(123);
  33     ui->textEdit->setText(qstr3);
  34 }