Qt学习:QLabel的用法及其程序示例

2022-08-03 13:52:51 浏览数 (1)

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主要成员函数:

1.void setText(QString); //设置label框内的文本. 2.void hide(); //隐藏label框. 3.void setBuddy(QWidget*); //把另一个部件设为label框的伙伴,方便快捷使用. 4.void clear(); //清空label框内所有内容. 5.void setPixmap(QPixmap(QString)); //设置图片. 6.void setMovie(QMovie*); //设置电影. 7.void setScaledContents(bool); //设置是否按比例填充满整个label框(非常重要) 8.void setToolTip(QString); //设置信息提示,鼠标放在label框上面会自动跳出文字. 9.void setToolTipDuration(int); //设置信息提示的持续时间,单位是毫秒. 10.void setAlignment(Qt::Alignment); //设置label框的对齐格式. 11.void setStyleSheet(QString); //设置label框的样式.


根据上面的QLabel的用法,下面有个关于QLabel的程序代码示例: 下面是程序运行后的情况:


首先进行通过Qt设计师进行布局:

以下是”c.cpp内的代码:”代码中包含注释,方便理解.

代码语言:javascript复制
#include "c.h"c::c(QWidget *parent)
    : QMainWindow(parent)
{    //应用Qt设计师
    ui.setupUi(this);    //修改标题.
    this->setWindowTitle(QString::fromLocal8Bit("QLabel的程序实例:"));    //给QStringList填充进去图片.
    initPictureList();    //给QMovie对象申请一块空间.
    movie = new QMovie;    //给两个QLabel对象设置新的文本.
    ui.movieLabel->setText(QString::fromLocal8Bit("未显示电影"));
    ui.pictureLabel->setText(QString::fromLocal8Bit("未显示图片"));    //设置两个label框的内容位于中间.
    ui.movieLabel->setAlignment(Qt::AlignCenter | Qt::AlignHCenter);
    ui.pictureLabel->setAlignment(Qt::AlignCenter | Qt::AlignHCenter);    //初始的时候上一张按钮时无法点击的,因为没有上一张.
    ui.previousPictureButton->setEnabled(false);    //给movieLabel设置提示框,当鼠标放在label上就会出现文字提示.
    ui.movieLabel->setToolTip(QString::fromLocal8Bit("电影真好看")); 
    //设置文字提示的持续时间为5000毫秒,也就是5秒后自动消失.
    ui.movieLabel->setToolTipDuration(1000);    //设置两个label框自动填充.
    ui.movieLabel->setScaledContents(true);
    ui.pictureLabel->setScaledContents(true);    //把printLineEdit设为printLabel的伙伴,这样的话你按alt R就会让光标位于行编辑框内.注意:设置label名字的时候要&R.
    ui.printLabel->setBuddy(ui.printLineEdit);    //连接信号与槽.
    connect(ui.startButton, SIGNAL(clicked()), this, SLOT(startMovieLabelSlot()));
    connect(ui.continueButton, SIGNAL(clicked()), this, SLOT(continueMovieLabelSlot()));
    connect(ui.previousPictureButton, SIGNAL(clicked()), this, SLOT(showPreviousPictureSlot()));
    connect(ui.nextPictureButton, SIGNAL(clicked()), this, SLOT(showNextPictureSlot()));
}

c::~c() {

}//点击开始按钮的槽函数.void c::startMovieLabelSlot() { //设置要播放的电影的路径.注意你要把gif文件放到对应的exe程序下. movie->setFileName(“Movie/0.gif”); //movieLabel应用movie. ui.movieLabel->setMovie(movie); //开始播放 movie->start(); }//点击暂停/继续按钮的槽函数.void c::continueMovieLabelSlot() { //判断当前电影的状态. if (movie->state() QMovie::Running) { movie->setPaused(true); ui.continueButton->setText(QString::fromLocal8Bit(“继续”)); } else if (movie->state() QMovie::Paused) { movie->setPaused(false); ui.continueButton->setText(QString::fromLocal8Bit(“暂停”)); } }void c::initPictureList() { //把所有照片的路径都放到QStringList里去. for (int i = 0; i < 10; i) { QString path = “Pixmap/” QString::number(i) “.jpg”; pictureList.push_back(path); } }//点击上一张按钮的槽函数.void c::showPreviousPictureSlot() { –pictureNumber; ui.pictureLabel->setPixmap(QPixmap(pictureList[pictureNumber])); if (pictureNumber 0) { ui.previousPictureButton->setEnabled(false); } ui.nextPictureButton->setEnabled(true); }//点击下一张按钮的槽函数.void c::showNextPictureSlot() { if (ui.pictureLabel->pixmap() != 0) pictureNumber; ui.pictureLabel->setPixmap(QPixmap(pictureList[pictureNumber])); if (pictureNumber 9) { ui.nextPictureButton->setEnabled(false); } if (pictureNumber != 0) ui.previousPictureButton->setEnabled(true); }123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107


以下是”c.h”内的代码:

代码语言:javascript复制
#ifndef C_H#define C_H#include <QtWidgets/QMainWindow>#include “ui_c.h”#include <QMessageBox>#include <QLabel>#include <QPushButton>#include <QMovie>#include <QPixmap>#include <QString>class c : public QMainWindow{
   
   

    Q_OBJECTpublic:

    c(QWidget *parent = 0);

    ~c();private slots:    void startMovieLabelSlot();    void continueMovieLabelSlot();    void showPreviousPictureSlot();    void showNextPictureSlot();private:    void initPictureList();

    Ui::cClass ui;

    QMovie *movie;

    QStringList pictureList;    int pictureNumber = 0;

};#endif // C_H1234567891011121314151617181920212223242526272829303132333435

最后是”main.cpp内的代码:”

代码语言:javascript复制
#include “c.h”#include <QtWidgets/QApplication>int main(int argc, char *argv[])

{
   
   

    QApplication a(argc, argv);

    c w;

    w.show();    return a.exec();

}1234567891011

关于QMovie类的操作可以去查阅Qt的官方文档进行学习,作一些扩展!

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