qt学习 实训第五天 第六天

第五天：

1.表示时间延迟

添加头文件QTimer,槽函数OnTimeOut,还有对象指针QTimer m_TimerFlush,

Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
m_TimeFlush.setInterval( 20 );  //计时
m_TimeFlush.start();

connect( &m_TimeFlush,SIGNAL(timeout()),this,SLOT(OnTimeOut())); //给程序一个消息，会一直弹出窗口，无法相应，只能强行的退出
}

void Dialog::OnTimeOut()
{
QMessageBox::information(this,"info","toue out now");
}

2.在label上显示数字，随时间的进行而变化

在头文件定义一个数字uint count，在构造函数中定义一个初始值，在OnTimeOut的函数中让count变化

Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);
m_TimeFlush.setInterval( 20 );  //计时
m_TimeFlush.start();

connect( &m_TimeFlush,SIGNAL(timeout()),this,SLOT(OnTimeOut())); //给程序一个消息，会一直弹出窗口，无法相应，只能强行的退出
count =0;
}
void Dialog::OnTimeOut()
{
ui->LE_TIME->setText( QString("%1").arg(count++));
}

3.按照时间的改变而图片变化：奇数时间是一张图片，偶数时间是另一张图片。

添加头文件

#includ<QImage>

定义新对象指针

QImage m_BKImage;

改变一下OnTimeOut函数：

if(count++ %2==0)
{
m_BKImage.load( "E:\\google download\\haha.jpg");
ui->LE_TIME->resize( m_BKImage.width(),m_BKImage.height());//设置宽高
ui->LE_TIME->setPixmap( QPixmap::fromImage( m_BKImage));   //加载图片
ui->LE_TIME->move( 0,0 );
}
else
{
m_BKImage.load( "C:\\Users\\Public\\Pictures\\Sample Pictures\\daa.jpg");
ui->LE_TIME->resize( m_BKImage.width(),m_BKImage.height());//设置宽高
ui->LE_TIME->setPixmap( QPixmap::fromImage( m_BKImage));   //加载图片
ui->LE_TIME->move( 0,0 );
}

4.显示板子当前的日期时间

使用QDateTime头文件即可，在OnTimeOut函数中改变：

ui->LE_TIME->setText( QString("%1").arg(count++));
QDateTime time = QDateTime::currentDateTime();
ui->LE_TIME->setText( time.toString("yyyy-MM-dd hh:mm:ss.zzz"));
//ui->LE_TIME->setText( QString("%1").arg(time.date().year()));
//ui->LE_TIME->setText( QString("%1").arg(time.date().month()));  //dayOfWeek    dayOfYear
//ui->LE_TIME->setText( QString("%1 %2").arg(time.date().day()).arg(time.time().hour()));
//ui->LE_TIME->setText( QString("%1").arg(time.time().hour()));
//ui->LE_TIME->setText( QString("%1").arg(time.toTime_t()));

改变时间的变化，不能没有变化，所以

ui->LE_TIME->setText( QString("%1").arg(count++));

下面注释掉的可以一个一个试试。而且点击label，在右边搜索区搜索font改变一下label的属性，文字格式的改变

5.使用LCD Number显示时间

设置LCD Number为LCD_DATE，在构造函数中添加

ui->LCD_DATE->setDigitCount(12);
ui->LCD_DATE->setSegmentStyle(QLCDNumber::Flat);
m_TimeFlush.setInterval(10);
m_TimeFlush.start();

connect(&m_TimeFlush,SIGNAL(timeout()),this,SLOT(OnTimeOut()));

4000
OnTimeOut();

然后在OnTimeOut的函数中为

QDateTime time = QDateTime::currentDateTime();
ui->LCD_DATE->display( time.toString("hh:mm:ss.zzz"));

第六天：

1.学习使用RadioButton

建立一个pushbutton，和radiobutton，并建立组

代码任务为：

1.建立一个组，让Fruit下的选项和select 下的选项能分开选择，并分别能显示出不同的提示。

2.在select选项中选择哪一项则按钮中显示哪项的文本。

ps:1.

#include<QButtonGroup>

可以建立 一个组，与别的radiobutton区别起来，可以分开的显示出来，单独的点击，比如在下面代码中，Fruit和man&woman分开，分别点击各自的选项，但是得单独的要把要区别出来的Fruit选项在构造函数中分别一个一个的添加并分配ID号。

dialog.h：
#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QButtonGroup>
namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
Q_OBJECT

public:
explicit Dialog(QWidget *parent = 0);
~Dialog();

private slots:
void OnBtMsgClicked();

void OnBtFruitClicked();

void OnRbFruitCliced();

private:
Ui::Dialog *ui;

QButtonGroup* m_BqFruit;

uint m_CheckedId;
};

#endif // DIALOG_H

dialog.cpp:
#include "dialog.h"
#include "ui_dialog.h"
#include <QMessageBox>

Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);

m_CheckedId=-1;

connect(ui->BT_MSG,SIGNAL(clicked() ),this,SLOT(OnBtMsgClicked()));

ui->RB_MAN->setChecked(true);

connect(ui->BT_Fruit,SIGNAL(clicked() ),this,SLOT(OnBtFruitClicked()));

m_BqFruit=NULL;
m_BqFruit=new QButtonGroup (this);
if(! m_BqFruit)
exit(1);

m_BqFruit->addButton( ui->RB_Apple,0);
m_BqFruit->addButton(ui->RB_Pear,1);
m_BqFruit->addButton(ui->RB_Cherry,2);

connect(ui->RB_Apple,SIGNAL(clicked() ),this,SLOT(OnRbFruitCliced()));
connect(ui->RB_Pear,SIGNAL(clicked() ),this,SLOT(OnRbFruitCliced()));
connect(ui->RB_Cherry,SIGNAL(clicked() ),this,SLOT(OnRbFruitCliced()));
}

Dialog::~Dialog()
{
delete ui;
if( m_BqFruit)
delete m_BqFruit;
}
void Dialog::OnBtMsgClicked()
{
if(ui->RB_MAN->isChecked() )
// QMessageBox::information(this,"info","You selectes man");
ui->BT_MSG->setText("MAN");
else if(ui->RB_WOMAN->isChecked())
// QMessageBox::information(this,"info","you selext woman");
ui->BT_MSG->setText("WOMAN");
else
QMessageBox::warning(this,"Warning","You are no selected");
}
void Dialog::OnBtFruitClicked()
{
QString info = "You selected ";

/*if(ui->RB_Apple->isChecked())
info +="apple";
else if(ui->RB_Cherry->isChecked())
info +="cherry";
else if(ui->RB_Pear->isChecked())
info += "pear";*/

switch(m_CheckedId)
{
case 0:info+="Apple";break;
case 1:info+="Pear";break;
case 2:info+="Cherry";break;
}

QMessageBox::warning(this," info",info);
}
void Dialog::OnRbFruitCliced()
{
m_CheckedId = m_BqFruit->checkedId();
}

2.控件的综合应用

任务：建立两个lineedit和两个PushButton,和两个RadioButton,让在lineedit中输入路径，并选择radiobutton的选项选择哪一个按下一个按钮可以显示出来图片，按下另一个按钮可以选择路径，并在lineedit中可以显示路径信息。

PS:把两个选项radiobutton分别的区别成一个小组，再分别出来显示不同的图片，把radiobutton与分配ID号的函数连接起来，再用ID号的不同把各自的不同图片显示出来。

dialog.h:
#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>
#include <QButtonGroup>

namespace Ui {
class Dialog;
}

class Dialog : public QDialog
{
Q_OBJECT

public:
explicit Dialog(QWidget *parent = 0);
~Dialog();

private slots:
void OnBtMsgClicked();

//  void ShowImage();

void OnRbFruitCliced();

private:
Ui::Dialog *ui;

QImage m_BKImage;

QButtonGroup* m_Image;

uint m_CheckedId;
};

#endif // DIALOG_H

dialog.cpp:
#include "dialog.h"
#include "ui_dialog.h"
#include <QMessageBox>
#include <QFileDialog>

Dialog::Dialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::Dialog)
{
ui->setupUi(this);

m_CheckedId=-1;

connect(ui->PB_IMAGE,SIGNAL(clicked() ),this,SLOT(OnBtMsgClicked()));

m_Image=NULL;
m_Image=new QButtonGroup(this);
if(!m_Image)
exit (1);
m_Image->addButton(ui->RB_IMAGE1,0);
m_Image->addButton(ui->RB_IMAGE2,1);

connect(ui->RB_IMAGE1,SIGNAL(clicked() ),this,SLOT(OnRbFruitCliced()));
connect(ui->RB_IMAGE2,SIGNAL(clicked() ),this,SLOT(OnRbFruitCliced()));

connect(ui->PB_Photo,SIGNAL(clicked()),this,SLOT(OnBtMsgClicked()));
}

Dialog::~Dialog()
{
delete ui;
}
void Dialog::OnBtMsgClicked()
{
if(ui->RB_IMAGE1->isChecked())
{
QString fileName1 = QFileDialog ::getOpenFileName(this,tr("Open File"),
"",
tr("Images (*.png *.bmp *.jpg)"));
if( ! m_BKImage.load(fileName1))
{
QMessageBox::warning(this,"warning","failes");
}                                                           //需要去掉几百个像素，或者可以使用把lineedit ： Bring to front，把label放在前面
ui->LE_IMAGE1->setText(fileName1);
ui->LB_IMAGE->resize( this->geometry().width() - 200,this->geometry().height() - 50);//设置宽高
ui->LB_IMAGE->setPixmap( QPixmap::fromImage(m_BKImage.scaled(this->geometry().width() - 100,this->geometry().height(),Qt::KeepAspectRatio)));   //加载图片
ui->LB_IMAGE->move( 0,0 );
}
else if(ui->RB_IMAGE2->isChecked())
{
QString fileName2 = QFileDialog ::getOpenFileName(this,tr("Open File"),
"",
tr("Images (*.png *.bmp *.jpg)"));
if( ! m_BKImage.load(fileName2))
{
QMessageBox::warning(this,"warning","failes");
}
/* ui->LB_IMAGE->resize( this->geometry().width(),this->geometry().height());//设置宽高
ui->LB_IMAGE->setPixmap( QPixmap::fromImage(m_BKImage.scaled(this->geometry().width(),this->geometry().height(),Qt::KeepAspectRatio)));   //加载图片
ui->LB_IMAGE->move( 0,0 );*/
ui->LE_IMAGE2->setText(fileName2);
ui->LB_IMAGE->resize( this->geometry().width() - 200,this->geometry().height() - 50);//设置宽高
ui->LB_IMAGE->setPixmap( QPixmap::fromImage(m_BKImage.scaled(this->geometry().width() - 100,this->geometry().height(),Qt::KeepAspectRatio)));   //加载图片
ui->LB_IMAGE->move( 0,0 );
}
}
void Dialog::OnRbFruitCliced()
{
m_CheckedId = m_Image->checkedId();
}