Qt精彩实例（1）

实例1.helloworld

hello.cpp
#include 
#include 
int main(int argc,char *argv[])
{
    QApplication app(argc, argv);
    QPushButton b("hello world");
    b.show();
    QObject::connect(&b, SIGNAL(clicked()), &app, SLOT(quit()));
    return app.exec();
}

实例2.文件，颜色，字体对话框

dialog.h
#ifndef DIALOG_H
#define DIALOG_H
#include 
#include 
#include 
#include 
#include 
#include 
#include 
namespace Ui {
    class Dialog;
}
class Dialog : public QDialog
{
    Q_OBJECT
public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
    QGridLayout *layout;
    QPushButton *filePushButton;
    QPushButton *colorPushButton;
    QPushButton *fontPushButton;
    QLineEdit *fileLineEdit;
    QLineEdit *fontLineEdit;
    QFrame *colorFrame;
private:
    Ui::Dialog *ui;
    
private slots:
    void slotOpenFileDlg();
    void slotOpenColorDlg();
    void slotOpenFontDlg();
};
#endif // DIALOG_H


dialog.cpp
#include "dialog.h"
#include "ui_dialog.h"
#include 
#include 
#include 
#include 
#include 
#include 
Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);setWindowTitle(tr("lalala"));
    layout = new QGridLayout(this);
    filePushButton = new QPushButton;
    filePushButton->setText(tr("file"));
    colorPushButton = new QPushButton;
    colorPushButton->setText(tr("color"));
    fontPushButton = new QPushButton;
    fontPushButton->setText(tr("font"));
    fileLineEdit = new QLineEdit;
    colorFrame = new QFrame;
    colorFrame->setFrameShape(QFrame::Box);
    colorFrame->setAutoFillBackground(true);
    fontLineEdit = new QLineEdit;
    fontLineEdit->setText(tr("hello world"));
    layout->addWidget(filePushButton,0,0);
    layout->addWidget(fileLineEdit,0,1);
    layout->addWidget(colorPushButton,1,0);
    layout->addWidget(colorFrame,1,1);
    layout->addWidget(fontPushButton,2,0);
    layout->addWidget(fontLineEdit,2,1);
    layout->setMargin(15);
    layout->setSpacing(10);
    connect(filePushButton, SIGNAL(clicked()), this, SLOT(slotOpenFileDlg()));
    connect(colorPushButton, SIGNAL(clicked()), this, SLOT(slotOpenColorDlg()));
    connect(fontPushButton, SIGNAL(clicked()), this, SLOT(slotOpenFontDlg()));
}
Dialog::~Dialog()
{
    delete ui;
}
void Dialog::slotOpenFileDlg()
{
    QString s = QFileDialog::getOpenFileName(
                    this,
                    "open file dialog",
                    "/",
                    "C++ files(*.cpp);;C files(*.c);;Hesd files(*.h)");
    fileLineEdit->setText(s.toAscii());
}
void Dialog::slotOpenColorDlg()
{
    QColor color = QColorDialog::getColor(Qt::blue);
    if(color.isValid())
    {
        colorFrame->setPalette(QPalette(color));
    }
}
void Dialog::slotOpenFontDlg()
{
    bool ok;
    QFont font = QFontDialog::getFont(&ok);
    if(ok)
    {
        fontLineEdit->setFont(font);
    }
}


main.cpp
#include 
#include "dialog.h"
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Dialog w;
    w.show();
    return a.exec();
}

实例3.位置函数的使用

dialog.h
#ifndef DIALOG_H
#define DIALOG_H
#include 
#include 
#include 
namespace Ui {
    class Dialog;
}
class Dialog : public QDialog
{
    Q_OBJECT
public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
    QGridLayout *layout;
    QLabel *xLabel;
    QLabel *yLabel;
    QLabel *frameGeoLabel;
    QLabel *posLabel;
    QLabel *geoLabel;
    QLabel *widthLabel;
    QLabel *heightLabel;
    QLabel *rectLabel;
    QLabel *sizeLabel;
    void updateLabel();
protected:
    void moveEvent(QMoveEvent*);
    void resizeEvent(QResizeEvent*);
private:
    Ui::Dialog *ui;
};
#endif // DIALOG_H


dialog.cpp
#include "dialog.h"
#include "ui_dialog.h"
#include 
Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    setWindowTitle("Qing");
    layout = new QGridLayout(this);
    xLabel = new QLabel;
    layout->addWidget(xLabel,1,0);
    yLabel = new QLabel;
    layout->addWidget(yLabel,2,0);
    frameGeoLabel = new QLabel;
    layout->addWidget(frameGeoLabel,3,0);
    posLabel = new QLabel;
    layout->addWidget(posLabel,4,0);
    geoLabel = new QLabel;
    layout->addWidget(geoLabel,5,0);
    widthLabel = new QLabel;
    layout->addWidget(widthLabel,6,0);
    heightLabel = new QLabel;
    layout->addWidget(heightLabel,7,0);
    rectLabel = new QLabel;
    layout->addWidget(rectLabel,8,0);
    sizeLabel = new QLabel;
    layout->addWidget(sizeLabel,9,0);
    layout->setMargin(25);
    layout->setSpacing(10);
    updateLabel();
}
Dialog::~Dialog()
{
    delete ui;
}
void Dialog::updateLabel()
{
    QString temp1,temp2,temp3,temp4;
    QString str_x;
    xLabel->setText("x():"+str_x.setNum(x()));
    QString str_y;
    yLabel->setText("y():"+str_y.setNum(y()));
    QString frameGeo;
    frameGeo = temp1.setNum(frameGeometry().x())+","+
               temp2.setNum(frameGeometry().y())+","+
               temp3.setNum(frameGeometry().width())+","+
               temp4.setNum(frameGeometry().height());
    frameGeoLabel->setText("frameGeometry():"+frameGeo);
    QString position;
    position = temp1.setNum(pos().x())+","+temp2.setNum(pos().y());
    posLabel->setText("pos():"+position);
    QString geo;
    geo = temp1.setNum(geometry().x())+","+
          temp2.setNum(geometry().y())+","+
          temp3.setNum(geometry().width())+","+
          temp4.setNum(geometry().height());
    geoLabel->setText("geometry():"+geo);
    QString w;
    widthLabel->setText("width():"+w.setNum(width()));
    QString h;
    heightLabel->setText("height():"+h.setNum(height()));
    QString r;
    r = temp1.setNum(rect().x())+","+
        temp2.setNum(rect().y())+","+
        temp3.setNum(rect().width())+","+
        temp4.setNum(rect().height());
    rectLabel->setText("rect():"+r);
    QString s;
    s = temp1.setNum(size().width())+","+
        temp2.setNum(size().height());
    sizeLabel->setText("size():"+s);
}
void Dialog::moveEvent(QMoveEvent*)
{
    updateLabel();
}
void Dialog::resizeEvent(QResizeEvent*)
{
    updateLabel();
}


main.cpp
#include 
#include "dialog.h"
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Dialog w;
    w.show();
    return a.exec();
}

实例4.姓名，性别，年龄，身高对话框

dialog.h
#ifndef DIALOG_H

#define DIALOG_H


#include 

#include 

#include 


namespace Ui {

    class Dialog;

}


class Dialog : public QDialog

{

    Q_OBJECT


public:

    explicit Dialog(QWidget *parent = 0);

    ~Dialog();


    QGridLayout *layout;


    QLabel *label1;

    QLabel *label2;

    QLabel *label3;

    QLabel *label4;

    QLabel *nameLabel;

    QLabel *sexLabel;

    QLabel *ageLabel;

    QLabel *statureLabel;


    QPushButton *nameButton;

    QPushButton *sexButton;

    QPushButton *ageButton;

    QPushButton *statureButton;


private:

    Ui::Dialog *ui;

private slots:

    void slotName();

    void slotSex();

    void slotAge();

    void slotStature();

};


#endif // DIALOG_H


dialog.cpp

#include "dialog.h"

#include "ui_dialog.h"

#include 


Dialog::Dialog(QWidget *parent) :

    QDialog(parent),

    ui(new Ui::Dialog)

{


    ui->setupUi(this);

    setWindowTitle(tr("Qing"));

    layout = new QGridLayout(this);


    label1 = new QLabel(tr("Name:"));

    label2 = new QLabel(tr("Sex:"));

    label3 = new QLabel(tr("Age:"));

    label4 = new QLabel(tr("height:"));


    nameLabel  = new QLabel(tr("LiMing"));

    nameLabel->setFrameStyle(QFrame::StyledPanel|QFrame::Plain);

    sexLabel  = new QLabel(tr("男"));

    sexLabel->setFrameStyle(QFrame::WinPanel|QFrame::Sunken);

    ageLabel = new QLabel(tr("25"));

    ageLabel->setFrameStyle(QFrame::Panel|QFrame::Sunken);

    statureLabel = new QLabel(tr("175.5"));

    statureLabel->setFrameStyle(QFrame::Box|QFrame::Raised);


    nameButton = new QPushButton;

    nameButton->setIcon(QIcon("G:/UI/images/fish.png"));

    sexButton = new QPushButton;

    sexButton->setIcon(QIcon("G:/UI/images/face.png"));

    ageButton = new QPushButton;

    //ageButton->setIcon(QIcon("btn.png"));

    statureButton = new QPushButton;

    //statureButton->setIcon(QIcon("btn.png"));



    layout->addWidget(label1,1,0);

    layout->addWidget(label2,2,0);

    layout->addWidget(label3,3,0);

    layout->addWidget(label4,4,0);


    layout->addWidget(nameLabel,1,1);

    layout->addWidget(sexLabel,2,1);

    layout->addWidget(ageLabel,3,1);

    layout->addWidget(statureLabel,4,1);


    layout->addWidget(nameButton,1,3);

    layout->addWidget(sexButton,2,3);

    layout->addWidget(ageButton,3,3);

    layout->addWidget(statureButton,4,3);


    connect(nameButton, SIGNAL(clicked()), this, SLOT(slotName()));

    connect(sexButton, SIGNAL(clicked()), this, SLOT(slotSex()));

    connect(ageButton, SIGNAL(clicked()), this, SLOT(slotAge()));

    connect(statureButton, SIGNAL(clicked()), this, SLOT(slotStature()));

}


Dialog::~Dialog()

{

    delete ui;

}


void Dialog::slotName()

{

    bool ok;

    QString name = QInputDialog::getText(this,tr("user name"),

                   tr("please input name"),QLineEdit::Normal,nameLabel->text(),&ok);

    if(ok & !name.isEmpty())

        nameLabel->setText(name);

}


void Dialog::slotSex()

{

    QStringList list;

    list << tr("male") << tr("female");

    bool ok;

    QString sex = QInputDialog::getItem(this,tr("Sex"),

                  tr("Please select sex"),list,0,false,&ok);

    if(ok)

        sexLabel->setText(sex);

}


void Dialog::slotAge()

{

    bool ok;

    int age = QInputDialog::getInteger(this,tr("usr age"),

              tr("Please inpuut age"),ageLabel->text().toInt(),0,150,1,&ok);

    if(ok)

    {

        ageLabel->setText(QString(tr("%1")).arg(age));

    }

}


void Dialog::slotStature()

{

    bool ok;

    double d = QInputDialog::getDouble(this,tr("Stature"),

               tr("Please input stature"),175.00,0,230.00,1,&ok);

    if(ok)

    {

        statureLabel->setText(QString(tr("%1")).arg(d));

    }

}


main.cpp

#include 

#include "dialog.h"

#include 

int main(int argc, char *argv[])

{

    QTextCodec::setCodecForTr(QTextCodec::codecForLocale());

    QApplication a(argc, argv);

    Dialog w;

    w.show();

    return a.exec();

}