标签：com blog style class div code c log size t ext
不得不吐（赞）槽（扬）一下《Linux窗口程序设计—Qt4精彩实例分析》，书中的示例基本上是不完整的，只给出了相应知识点的实现，若要完整地运行整个工程，这需要读者来添加其余代码。在添加代码的过程中，因为不熟，常常是战战兢兢的，查很多资料，然后才敢往上写点代码，有时候挺浪费时间的。
今天学示例3和4，各类位置信息，各类标准输入框。
在编译时遇见一个错误：undefined reference to vtable for。
查资料找到解决方法，先qmake然后再构建，再运行即可。虽然解决了这个问题，但我完全不清楚错在哪里，网上的意见也都莫衷一是，只能等经验积累了，再来分析问题。
代码：
// geometry.h#ifndef GEOMETRY_H#define GEOMETRY_H#include <QDialog>#include <QWidget>#include <QGridLayout>#include <QFrame>#include <QString>#include <QLabel>class
Geometry: public
QDialog{ Q_OBJECTpublic: Geometry(QWidget *parent = 0, Qt::WindowFlags f = 0); ~Geometry(); // 声明所需的空间，主要为QLabel类 QLabel * xLabel; QLabel * xString; QLabel * yLabel; QLabel * yString; QLabel * frameGeoLabel; QLabel * frameGeoString; QLabel * posLabel; QLabel * posString; QLabel * geoLabel; QLabel * geoString; QLabel * widthLabel; QLabel * widthString; QLabel * heightLabel; QLabel * heightString; QLabel * rectLabel; QLabel * rectString; QLabel * sizeLabel; QLabel * sizeString; QGridLayout *layout; void
updateLabel();protected: void
moveEvent(QMoveEvent*); void
resizeEvent(QResizeEvent*);};#endif // GEOMETRY_H//geometry.cpp#include "geometry.h"Geometry::Geometry(QWidget *parent, Qt::WindowFlags f) :QDialog(parent, f){ setWindowTitle("Geometry"); // 创建程序所需的各控件 xString = new
QLabel; xString->setText(tr("x():")); xLabel = new
QLabel; yString = new
QLabel; yString->setText(tr("y():")); yLabel = new
QLabel; frameGeoString = new
QLabel; frameGeoString->setText(tr("frameGeometry():")); frameGeoLabel = new
QLabel; posString = new
QLabel; posString->setText(tr("pos():")); posLabel = new
QLabel; geoString = new
QLabel; geoString->setText(tr("geometry():")); geoLabel = new
QLabel; widthString = new
QLabel; widthString->setText(tr("width():")); widthLabel = new
QLabel; heightString = new
QLabel; heightString->setText(tr("height()")); heightLabel = new
QLabel; rectString = new
QLabel; rectString->setText(tr("rect():")); rectLabel = new
QLabel; sizeString = new
QLabel; sizeString->setText(tr("size():")); sizeLabel = new
QLabel; // 布局 setWindowTitle(tr("GeoMetrys ")); layout = new
QGridLayout(this); layout->addWidget(xString, 0, 0); layout->addWidget(xLabel,0, 1); layout->addWidget(yString, 1,0); layout->addWidget(yLabel, 1, 1); layout->addWidget(frameGeoString, 2, 0); layout->addWidget(frameGeoLabel, 2, 1); layout->addWidget( posString, 3, 0); layout->addWidget( posLabel, 3, 1); layout->addWidget( geoString, 4, 0); layout->addWidget( geoLabel, 4, 1); layout->addWidget( widthString, 5, 0); layout->addWidget( widthLabel, 5, 1); layout->addWidget( heightString, 6, 0); layout->addWidget( heightLabel, 6, 1); layout->addWidget( rectString, 7, 0); layout->addWidget( rectLabel, 7, 1); layout->addWidget( sizeString, 8, 0); layout->addWidget( sizeLabel, 8, 1); layout->setMargin(15); layout->setSpacing(10); updateLabel();}Geometry::~Geometry(){ delete
xLabel; delete
xString; delete
yLabel; delete
yString; delete
frameGeoLabel; delete
frameGeoString; delete
posLabel; delete
posString; delete
geoLabel; delete
geoString; delete
widthLabel; delete
widthString; delete
heightLabel; delete
heightString; delete
rectLabel; delete
rectString; delete
sizeLabel; delete
sizeString; delete
layout;}void
Geometry::updateLabel(){ QString temp; QString str_x; xLabel->setText(str_x.setNum(x())); QString str_y; yLabel->setText(str_y.setNum(y())); QString frameGeo; frameGeo = temp.setNum(frameGeometry().x()) + ","
+ temp.setNum(frameGeometry().y()) + ","
+ temp.setNum(frameGeometry().width()) + ","
+ temp.setNum(frameGeometry().height()); frameGeoLabel->setText(frameGeo); QString position; position = temp.setNum(pos().x()) + ","
+temp.setNum(pos().y()); posLabel->setText(position); QString geo; geo = temp.setNum(geometry().x()) + ","
+ temp.setNum(geometry().y()) + ","
+ temp.setNum(geometry().width()) + ","
+ temp.setNum(geometry().height()); geoLabel->setText(geo); QString w; widthLabel->setText(w.setNum(width())); QString h; heightLabel->setText(h.setNum(height())); QString r; r = temp.setNum(rect().x()) + ","
+ temp.setNum(rect().y()) + ","
+ temp.setNum(rect().width()) + ","
+ temp.setNum(rect().height()); rectLabel->setText(r); QString s; s = temp.setNum(size().width()) + ","
+ temp.setNum(size().height()); sizeLabel->setText(s);}void
Geometry::moveEvent(QMoveEvent *) //下面两个函数继承自QWidget，所以毋须再Geometry构造函数中显式调用{ updateLabel();}void
Geometry::resizeEvent(QResizeEvent *){ updateLabel();}//main.cpp#include <QApplication>#include <QPushButton>#include <QLabel>#include "standarddialogs.h"#include "geometry.h"int
main(int
argc, char
*argv[]){ QApplication a(argc, argv); // StandardDialogs ct; // ct.show(); // QPushButton b("Hello World!"); // b.show(); // QObject::connect(&b, SIGNAL(clicked()), &a, SLOT(quit())); Geometry my; my.show(); return
a.exec();} |
// inputdialog.h#ifndef INPUTDIALOG_H#define INPUTDIALOG_H#include <QDialog>#include <QLabel>#include <QPushButton>#include <QGridLayout>#include <QString>#include <QInputDialog>#include <QLineEdit>class
InputDlg: public
QDialog{ Q_OBJECTpublic: InputDlg(); ~InputDlg();public: QPushButton *nameButton; QPushButton *sexButton; QPushButton *ageButton; QPushButton *statureButton; QLabel *label1; QLabel *label2; QLabel *label3; QLabel *label4; QLabel *nameLabel; QLabel *sexLabel; QLabel *ageLabel; QLabel *statureLabel; QGridLayout *layout;private
slots: void
slotName(); void
slotSex(); void
slotAge(); void
slotStature();};#endif // INPUTDIALOG_H// inputdialog.cpp#include "inputdialog.h"InputDlg::InputDlg(){ setWindowTitle(tr("Input Dialog")); // 创建各标签对象 label1 = new
QLabel(tr("Name:")); label2 = new
QLabel(tr("Sex:")); label3 = new
QLabel(tr("Age:")); label4 = new
QLabel(tr("High:")); // 创建各显示标签 nameLabel = new
QLabel(tr("LiMing")); nameLabel->setFrameStyle(QFrame::Panel|QFrame::Sunken); //QFrame::Panel 0x0002 QFrame draws a panel to make the contents appear raised or sunken sexLabel = new
QLabel(tr("Male")); sexLabel->setFrameStyle(QFrame::Panel | QFrame::Raised); ageLabel = new
QLabel(tr("25")); ageLabel->setFrameStyle(QFrame::Panel | QFrame::Raised); statureLabel = new
QLabel(tr("175.5")); statureLabel->setFrameStyle(QFrame::Panel | QFrame::Raised); // 创建各修改按钮 nameButton = new
QPushButton; // nameButton->setIcon(QIcon("btn.png")); sexButton = new
QPushButton; // sexButton->setIcon(QIcon("btn.png")); ageButton = new
QPushButton; // ageButton->setIcon(QIcon("btn.png")); statureButton = new
QPushButton; // statureButton->setIcon(QIcon("btn.png")); // 布局 layout = new
QGridLayout(this); layout->addWidget(label1, 0, 0); layout->addWidget(nameLabel, 0, 1); layout->addWidget(nameButton, 0, 2); layout->addWidget(label2, 1, 0); layout->addWidget(sexLabel, 1, 1); layout->addWidget(sexButton, 1, 2); layout->addWidget(label3, 2, 0); layout->addWidget(ageLabel, 2, 1); layout->addWidget(ageButton, 2, 2); layout->addWidget(label4, 3, 0); layout->addWidget(statureLabel, 3, 1); layout->addWidget(statureButton, 3, 2); // 连接信号与槽函数 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()));}InputDlg::~InputDlg(){ delete
label1; delete
label2; delete
label3; delete
label4; delete
layout; delete
nameLabel; delete
ageLabel; delete
sexLabel; delete
statureLabel; delete
nameButton; delete
sexButton; delete
ageButton; delete
statureButton;}void
InputDlg::slotName(){ bool
ok; QString name = QInputDialog::getText(this, tr("User Name"), // this 表示父窗口，是QWidget对象指针, The QWidget class is the base class of all user interface objects. tr("Please input new name:"), QLineEdit::Normal, nameLabel->text(), &ok); if(ok & !name.isEmpty()) // 此处书中有错误，将&写成了&&，查了qt的help文档，没发现有&&这个运算符号 { nameLabel->setText(name); }}void
InputDlg::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
InputDlg::slotAge(){ bool
ok; int
age = QInputDialog::getInteger(this, tr("User Age"), tr("Please input age:"), ageLabel->text().toInt(), 0, 150, 1, &ok); if
(ok) ageLabel->setText(QString(tr("%1")).arg(age)); // 数字显示成字符串的方法，也说明setText必须接收字符串输入，原型为 void setText(const QString &) |
}void
InputDlg::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 <QApplication>#include <QPushButton>#include <QLabel>#include "standarddialogs.h"#include "geometry.h"#include "inputdialog.h"int
main(int
argc, char
*argv[]){ QApplication a(argc, argv); // StandardDialogs ct; // ct.show(); // QPushButton b("Hello World!"); // b.show(); // QObject::connect(&b, SIGNAL(clicked()), &a, SLOT(quit())); // Geometry my; // my.show(); InputDlg person; person.show(); return
a.exec();} |
【qt学习002】各类位置信息和各类标准输入框,码迷,mamicode.com
标签：com blog style class div code c log size t ext
原文地址：http://www.cnblogs.com/xy-kidult/p/3699106.html
