我正在尝试使用幻灯片放映创建图像查看器。当用户点击播放按钮时,观看者开始显示图像。当用户点击停止按钮时,查看器停止显示图像。停止后,当用户再次点击播放按钮时,观众将继续显示剩余的图像。我的问题是,当用户点击停止按钮并再次点击播放按钮时,我不知道如何重复使用在开头创建的同一窗口来显示剩余的图像。
Button3是播放按钮。
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QFileSystemModel>
#include "showpic.h"
#include <QBasicTimer>
#include <QTimer>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private slots:
void on_pushButton_3_clicked();
void tick();
void on_pushButton_4_clicked();
private:
Ui::MainWindow *ui;
QFileSystemModel *model;
QString filesPath;
ShowPic *showpic;
QStringList filenames;
QStringList::const_iterator m_imageIt;
QTimer m_timer;
};
#endif // MAINWINDOW_H
showpic.h
#ifndef SHOWPIC_H
#define SHOWPIC_H
#include <QWidget>
namespace Ui {
class ShowPic;
}
class ShowPic : public QWidget
{
Q_OBJECT
public:
explicit ShowPic(QWidget *parent = 0);
~ShowPic();
private:
Ui::ShowPic *ui;
public:
void addPixmap(const QPixmap &pixmap);
};
#endif // SHOWPIC_H
的main.cpp
#include "mainwindow.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QFileDialog>
#include<QFileSystemModel>
#include<QStringList>
#include <QTreeView>
#include <QGraphicsScene>
#include <QTime>
#include <QDebug>
#include <iostream>
#include <QTimer>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
filenames.append("C:\\test\\image.jpg");
filenames.append("C:\\test\\apple.jpg");
filenames.append("C:\\test\\orange.jpg");
filenames.append("C:\\test\\lemon.jpg");
filenames.append("C:\\test\\grape.jpg");
m_timer.setInterval(1000);
connect(&m_timer, SIGNAL(timeout()), this, SLOT(tick()));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::tick(){
showpic->addPixmap(*m_imageIt);
m_imageIt ++;
if(m_imageIt == filenames.end()){
m_timer.stop();
m_imageIt = filenames.begin();
}
}
void MainWindow::on_pushButton_3_clicked() //click on the play button
{
if(!filenames.isEmpty()){ // initial click
showpic = new ShowPic();
m_timer.start();
showpic->setWindowState(Qt::WindowMaximized);
showpic->show();
} else if( ) { // click on the play button again,
m_timer.start(); //???
showpic->setWindowState(Qt::WindowMaximized); //???
showpic->show(); //???
}
}
void MainWindow::on_pushButton_4_clicked() // click on the stop button
{
m_timer.stop();
}
showpic.cpp
#include "showpic.h"
#include "ui_showpic.h"
ShowPic::ShowPic(QWidget *parent) :
QWidget(parent),
ui(new Ui::ShowPic)
{
ui->setupUi(this);
ui->graphicsView->setScene(new QGraphicsScene);
ui->horizontalLayout->addWidget(ui->graphicsView);
this->setLayout(ui->horizontalLayout);
}
ShowPic::~ShowPic()
{
delete ui;
}
void ShowPic::addPixmap(const QPixmap &pixmap){
ui->horizontalLayout->addWidget(ui->graphicsView);
this->setLayout(ui->horizontalLayout);
ui->graphicsView->setScene(new QGraphicsScene);
ui->graphicsView->scene()->addPixmap(pixmap);
ui->graphicsView->fitInView(ui->graphicsView->scene()->itemsBoundingRect() ,Qt::KeepAspectRatio);
}
答案 0 :(得分:0)
on_pushButton_3_clicked的其他部分在任何情况下都不会运行,因为MainWindow创建时会填充文件名。在您的代码中,您可以在每次点击时创建新的showpic。
首先,在MainWindow的构造函数中将showpic设置为NULL;
showpic = NULL;
并像这样更改on_pushButton_3_clicked方法;
void MainWindow::on_pushButton_3_clicked() //click on the play button
{
if(showpic == NULL){
showpic = new ShowPic();
}
if(!showpic->isVisible()){
showpic->setWindowState(Qt::WindowMaximized);
showpic->show();
}
m_timer.start();
}
最后,我现在没有QT,所以我的回答可能包含拼写错误/语法错误。
答案 1 :(得分:0)
这对我有用。我测试了场景清理方法,它对我来说很好。但是在这里我决定只将指针存储到QGraphicsPixmapItem
作为成员变量,并且只是为它设置一个新的像素图,而不是经常清除场景。对我来说这样看起来更优雅。
#include <QtWidgets>
class SlideView : public QWidget
{
Q_OBJECT
public:
SlideView(QWidget *parent = nullptr) : QWidget(parent)
{
setLayout(new QHBoxLayout);
layout()->addWidget(&view);
view.setScene(new QGraphicsScene(this));
pixmap_item = new QGraphicsPixmapItem;
view.scene()->addItem(pixmap_item);
}
void setPixmap(const QPixmap &pixmap)
{
pixmap_item->setPixmap(pixmap);
view.fitInView(view.scene()->itemsBoundingRect(), Qt::KeepAspectRatio);
}
private:
QGraphicsView view;
QGraphicsPixmapItem *pixmap_item = nullptr;
};
class MainWidget : public QWidget
{
Q_OBJECT
public:
MainWidget(QWidget *parent = nullptr) : QWidget(parent)
{
slide_iterator = slides.begin();
setLayout(new QHBoxLayout);
QPushButton *play_button = new QPushButton("Play");
QPushButton *stop_button = new QPushButton("Stop");
layout()->addWidget(play_button);
layout()->addWidget(stop_button);
connect(play_button, &QPushButton::clicked, this, &MainWidget::play);
connect(stop_button, &QPushButton::clicked, this, &MainWidget::stop);
connect(&timer, &QTimer::timeout, this, &MainWidget::showNextSlide);
}
public slots:
void play() {timer.start(1000); view.showMaximized(); view.activateWindow();}
void stop() {timer.stop();}
void showNextSlide()
{
QPixmap pixmap(*slide_iterator);
view.setPixmap(pixmap);
slide_iterator++;
if(slide_iterator == slides.end())
slide_iterator = slides.begin();
}
private:
QTimer timer;
QStringList slides{"one.png", "two.png", "three.png"};
QStringList::const_iterator slide_iterator;
SlideView view;
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWidget w;
w.show();
return a.exec();
}
#include "main.moc"