《Qt5 开发与实例（第三版）》学习笔记（五）

  1 //2.5 控件
  2 //2.51 按钮组(Buttons)
  3 /*
  4 Radio Button //单选按钮
  5 Check Box//复选框
  6 Dialog Button Box//对话框按钮盒
  7 */
  8 //main.cpp
  9 #include "mywidget.h"
 10 #include <QApplication>
 11 
 12 int main(int argc, char *argv[])
 13 {
 14     QApplication a(argc, argv);
 15     MyWidget w;//创建一个MyWidget对象
 16     w.setGeometry(100,100,200,120);//设置其长宽
 17     w.show();
 18 
 19     return a.exec();
 20 }
 21 //mywidget.h
 22 #include "mywidget.h"
 23 #include <qapplication.h>
 24 #include <qpushbutton.h>//用到了按钮，因此添加相应的头文件
 25 #include <qfont.h>
 26 MyWidget::MyWidget(QWidget *parent)
 27     : QWidget(parent)
 28 {
 29     setMinimumSize(200,120);
 30     setMaximumSize(200,120);
 31     QPushButton *quit = new QPushButton("Quit",this);//先记住
 32     quit->setGeometry(62,40,75,30);
 33     quit->setFont(QFont("Times",18,QFont::Bold));
 34     connect(quit,SIGNAL(clicked()),qApp,SLOT(quit()));
 35 }
 36 
 37 MyWidget::~MyWidget()
 38 {
 39 
 40 }
 41 //2.52 输入部件组(Input Widgets)
 42 /*
 43 combo box 组合框
 44 spin box 数字显示框
 45 dial 拨号
 46 scroll bar 滚动条
 47 slider 滑块
 48 key sequence edit 按键序列编辑框
 49 */
 50 //QDate Time
 51 QLabel * datalabel = new QLabel();
 52 QDateTime * datatime = new QDateTime(QDateTime::currentDateTime());
 53 datalabel->setText(datatime->date().toString());
 54 datalabel->show();
 55 //QTime
 56 QTimer *time_clock = new QTimer(parent);
 57 connect(time_clock,SIGNAL(timeout()),this,SLOT(slottimedone()));//定时时间一到发送timeout()信号，从而触发slottimedone()槽去完成某件事情
 58 start(int time)//每隔time秒触发定时
 59 setSingleShot(true)//仅启动一次
 60 stop()//关掉定时器
 61 time_clock->start(2000)//示例
 62 //2.53 显示控件组(Display Widgets)
 63 LCD Number//液晶数字
 64 Progress Bar//进度条
 65 OpenGL widget//开放式图形库工具
 66 QQuickWidget//嵌入QML工具
 67 
 68 Text Browser 介绍
 69 属性见 P48
 70 SLOTS：
 71 virtual void backward()
 72 virtual void forward()
 73 virtual void home()
 74 
 75 //widget.h
 76 #ifndef WIDGET_H
 77 #define WIDGET_H
 78 
 79 #include <QWidget>
 80 #include <QTreeWidgetItem>
 81 namespace Ui {
 82 class Widget;
 83 }
 84 
 85 class Widget : public QWidget
 86 {
 87     Q_OBJECT
 88 
 89 public:
 90     explicit Widget(QWidget *parent = 0);
 91     void init();
 92     ~Widget();
 93     void updateParentItem(QTreeWidgetItem* item);
 94 public slots:
 95     void treeItemChanged (QTreeWidgetItem* item,int column);
 96 
 97 private:
 98     Ui::Widget *ui;
 99 };
100 
101 #endif // WIDGET_H
102 
103 //widget.cpp
104 #include "widget.h"
105 #include "ui_widget.h"
106 
107 Widget::Widget(QWidget *parent) :
108     QWidget(parent),
109     ui(new Ui::Widget)
110 {
111     init();//?
112     connect(ui->treeWidget,SIGNAL(itemChanged(QTreeWidgetItem*,int)),this,SLOT(treeItemChanged(QTreeWidgetItem*,int)));//SIGNAL & SLot
113     ui->setupUi(this);
114 }
115 
116 Widget::~Widget()
117 {
118     delete ui;
119 }
120 void Widget::init()
121 {
122     ui->treeWidget->clear();
123     //1
124     QTreeWidgetItem *group1 = new QTreeWidgetItem(ui->treeWidget);
125     group1->setText(0,"group1");
126     group1->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
127     group1->setCheckState(0,Qt::Unchecked);
128     QTreeWidgetItem *subItem11 = new QTreeWidgetItem(group1);
129     subItem11->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
130     subItem11->setText(0,"subItem11");
131     subItem11->setCheckState(0,Qt::Unchecked);
132     QTreeWidgetItem *subItem12 = new QTreeWidgetItem(group1);
133     subItem12->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
134     subItem12->setText(0,"subItem12");
135     subItem12->setCheckState(0,Qt::Unchecked);
136     QTreeWidgetItem *subItem13 = new QTreeWidgetItem(group1);
137     subItem13->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
138     subItem13->setText(0,"subItem13");
139     subItem13->setCheckState(0,Qt::Unchecked);
140     //2
141     QTreeWidgetItem *group2 = new QTreeWidgetItem(ui->treeWidget);
142     group2->setText(0,"group2");
143     group2->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
144     group2->setCheckState(0,Qt::Unchecked);
145     QTreeWidgetItem *subItem21 = new QTreeWidgetItem(group2);
146     subItem21->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
147     subItem21->setText(0,"subItem21");
148     subItem21->setCheckState(0,Qt::Unchecked);
149     QTreeWidgetItem *subItem22 = new QTreeWidgetItem(group2);
150     subItem22->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
151     subItem22->setText(0,"subItem22");
152     subItem22->setCheckState(0,Qt::Unchecked);
153     QTreeWidgetItem *subItem23 = new QTreeWidgetItem(group2);
154     subItem23->setFlags(Qt::ItemIsUserCheckable|Qt::ItemIsEnabled|Qt::ItemIsSelectable);
155     subItem23->setText(0,"subItem23");
156     subItem23->setCheckState(0,Qt::Unchecked);
157 }
158 
159 void Widget::treeItemChanged(QTreeWidgetItem *item, int column)
160 {
161     QString itemText = item->text(0);
162     if (Qt::Checked==item->checkState(0))
163     {
164         QTreeWidgetItem* parent = item->parent();
165         int count=item->childCount();
166         if(count>0)
167         {
168             for(int i=0;i<count;i++)
169             {
170                 item->child(i)->setCheckState(0,Qt::Checked);
171             }
172         }
173         else
174         {
175             updateParentItem(item);
176         }
177     }
178     else if(Qt::Unchecked == item->checkState(0))
179     {
180         int count = item->childCount();
181         if(count>0)
182         {
183             for(int i=0;i<count;i++)
184             {
185                 item->child(i)->setCheckState(0,Qt::Unchecked);
186             }
187         }
188         else
189         {
190             updateParentItem(item);
191         }
192     }
193 }
194 void Widget::updateParentItem(QTreeWidgetItem *item)
195 {
196     QTreeWidgetItem *parent = item->parent();
197     if(parent == NULL)
198     {
199         return;
200     }
201     int selectedCount = 0;
202     int childCount = parent->childCount();
203     for(int i =0;i<childCount;++i)
204     {
205         QTreeWidgetItem* childItem = parent->child(i);
206         if(childItem->checkState(0)==Qt::Checked)
207         {
208             selectedCount++;
209         }
210     }
211     if(selectedCount<=0)
212     {
213         parent->setCheckState(0,Qt::Unchecked);
214     }
215     else if(selectedCount>0&&selectedCount<childCount)
216     {
217         parent->setCheckState(0,Qt::PartiallyChecked);
218     }
219     else if(selectedCount == childCount)
220     {
221         parent->setCheckState(0,Qt::Checked);
222     }
223 }
224 
225 
226 //main.cpp
227 #include "widget.h"
228 #include <QApplication>
229 
230 int main(int argc, char *argv[])
231 {
232     QApplication a(argc, argv);
233     Widget w;
234     w.show();
235 
236     return a.exec();
237 }
238 
239 
240 //dialog.h
241 private slots:
242     void on_lineEdit_textChanged();//定义一个槽；名字的定义有一定规则
243 //dialog.cpp
244 Dialog::Dialog(QWidget *parent) :
245     QDialog(parent),
246     ui(new Ui::Dialog)
247 {
248     ui->setupUi(this);
249     QRegExp regExp("[A-Za-z][1-9][0-9]{0,2}");//建立一个正则表达式
250     ui->lineEdit->setValidator(new QRegExpValidator(regExp,this));//先记住如何使用
251     connect(ui->okButton,SIGNAL(clicked(bool)),this,SLOT(accept()));//信号与槽的连接
252     connect(ui->cancelButton,SIGNAL(clicked(bool)),this,SLOT(reject()));
253 }
254 void Dialog::on_lineEdit_textChanged()//定义槽函数
255 {
256     ui->okButton->setEnabled(ui->lineEdit->hasAcceptableInput());//使用lineEdit输入文本的有效性决定okButton的可操作性
257 }