小部件不正确可见

Widget is not properly visible

本文关键字：不正确 小部      更新时间：2023-10-16

在此代码中，能够播放视频和播放*.mp3。代码正常工作，在我的mainwindow.ui中，我添加了drag drop。添加了名为 widgetGif的小部件。也包含标签的小部件。但是，当我运行程序时，这个小部件不可见。我如何显示这个名为widgetGif

的小部件

这是我的代码的一部分：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <QMovie>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    player = new QMediaPlayer(this);
    vw = new QVideoWidget (this);
    player->setVideoOutput(vw);
    this->setCentralWidget(vw); //I think this is the reason
    slider = new QSlider(this);
    bar = new QProgressBar(this);
    slider->setOrientation(Qt::Horizontal);
    ui->statusBar->addPermanentWidget(slider);
    ui->statusBar->addPermanentWidget(bar);

    connect(player,&QMediaPlayer::durationChanged,slider,&QSlider::setMaximum);
    connect(player,&QMediaPlayer::positionChanged,slider,&QSlider::setValue);
    connect(slider,&QSlider::sliderMoved,player,&QMediaPlayer::setPosition);
    connect(player,&QMediaPlayer::durationChanged,bar,&QProgressBar::setMaximum);
    connect(player,&QMediaPlayer::positionChanged,bar,&QProgressBar::setValue);

    sliderVolumn = new QSlider(this);
    sliderVolumn->setOrientation(Qt::Horizontal);
    ui->statusBar->addPermanentWidget(sliderVolumn);
    connect(sliderVolumn,&QSlider::sliderMoved,player,&QMediaPlayer::setVolume);
    QMovie *movie=new QMovie(":/res/icons/giphy.gif");
    if (!movie->isValid())
    {
        // Something went wrong :(
    }
    ui->labelGif->setMovie(movie);
    movie->start();
    ui->widgetGif->setVisible(true);
}

MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::on_actionOpen_triggered()
{
    QString filename= QFileDialog::getOpenFileName(this,"Open Folder","","Open a File(*.*)");
    on_actionStop_triggered();
    player->setMedia(QUrl::fromLocalFile(filename));
    on_actionPlay_triggered();
    if(filename.endsWith(".mp3")){
        qDebug() << " file is mp3";
    }else{
        qDebug() << " not is mp3";
    }
}

QMainWindow需要centralWidget。您必须使用布局来包括您的QVideoWidget和widgetGif，然后将其设置为QMainWindow的centralWidget。

在以下示例中，textEdit将是您的QVideoWidget，并且对象label就像您的widgetGif。

我们还有两个按钮可以使用方法setVisible。

隐藏或显示label

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.h 

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class QLabel;
class QPushButton;
class QTextEdit;
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
private:
    Ui::MainWindow *ui;
    QWidget *centralWidget;
    QLabel *label;
    QPushButton *pushButton;
    QPushButton *pushButton_2;
    QTextEdit *textEdit;
public slots:
    void showSlot();
    void hideSlot();
};
#endif // MAINWINDOW_H

mainwindow.cpp 

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QVBoxLayout>
#include <QLabel>
#include <QPushButton>
#include <QTextEdit>
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    // Vertical layout
    QVBoxLayout *mainLayout = new QVBoxLayout;
    // Widgets
    centralWidget = new QWidget(this);
    label = new QLabel();
    pushButton = new QPushButton();
    pushButton_2 = new QPushButton();
    textEdit = new QTextEdit();
    // Title and texts
    this->setWindowTitle("MainWindow");
    label->setText("TextLabel");
    pushButton->setText("Show");
    pushButton_2->setText("Hide");
    // Add widgets to layout
    mainLayout->addWidget(textEdit);
    mainLayout->addWidget(label);
    mainLayout->addWidget(pushButton);
    mainLayout->addWidget(pushButton_2);
    centralWidget->setLayout(mainLayout);
    // Set the central widget
    this->setCentralWidget(centralWidget);
    connect(pushButton, SIGNAL (clicked()), this, SLOT (showSlot()));
    connect(pushButton_2, SIGNAL (clicked()), this, SLOT (hideSlot()));
}
MainWindow::~MainWindow()
{
    delete ui;
}
void MainWindow::showSlot()
{
    label->setVisible(true);
}
void MainWindow::hideSlot()
{
    label->setVisible(false);
}
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