Qt-Qt之QVariant的使用分析

相关资料：

https://download.csdn.net/download/zhujianqiangqq/85800729     CSDN代码包下载

代码实例：

.pro

 1 QT       += core gui
 2 
 3 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 4 
 5 CONFIG += c++11
 6 
 7 # The following define makes your compiler emit warnings if you use
 8 # any Qt feature that has been marked deprecated (the exact warnings
 9 # depend on your compiler). Please consult the documentation of the
10 # deprecated API in order to know how to port your code away from it.
11 DEFINES += QT_DEPRECATED_WARNINGS
12 
13 # You can also make your code fail to compile if it uses deprecated APIs.
14 # In order to do so, uncomment the following line.
15 # You can also select to disable deprecated APIs only up to a certain version of Qt.
16 #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
17 
18 SOURCES += \
19     main.cpp \
20     mainwindow.cpp
21 
22 HEADERS += \
23     mainwindow.h
24 
25 FORMS += \
26     mainwindow.ui
27 
28 # Default rules for deployment.
29 qnx: target.path = /tmp/$${TARGET}/bin
30 else: unix:!android: target.path = /opt/$${TARGET}/bin
31 !isEmpty(target.path): INSTALLS += target
View Code

main.cpp

 1 #include "mainwindow.h"
 2 
 3 #include <QApplication>
 4 
 5 int main(int argc, char *argv[])
 6 {
 7     QApplication a(argc, argv);
 8     MainWindow w;
 9     w.show();
10     return a.exec();
11 }
View Code

mainwindow.h

 1 #ifndef MAINWINDOW_H
 2 #define MAINWINDOW_H
 3 
 4 #include <QMainWindow>
 5 #include <QVariant>
 6 
 7 QT_BEGIN_NAMESPACE
 8 namespace Ui { class MainWindow; }
 9 QT_END_NAMESPACE
10 
11 class MainWindow : public QMainWindow
12 {
13     Q_OBJECT
14 
15 public:
16     MainWindow(QWidget *parent = nullptr);
17     ~MainWindow();
18 
19 private slots:
20     void on_pushButton_2_clicked();
21 
22     void on_pushButton_clicked();
23 
24     void on_pushButton_9_clicked();
25 
26     void on_pushButton_10_clicked();
27 
28     void on_pushButton_4_clicked();
29 
30     void on_pushButton_3_clicked();
31 
32     void on_pushButton_11_clicked();
33 
34     void on_pushButton_6_clicked();
35 
36     void on_pushButton_12_clicked();
37 
38     void on_pushButton_5_clicked();
39 
40     void on_pushButton_13_clicked();
41 
42     void on_pushButton_14_clicked();
43 
44 private:
45     Ui::MainWindow *ui;
46     QVariant m_pVariant;
47 };
48 #endif // MAINWINDOW_H
View Code

mainwindow.cpp

 1 #include "mainwindow.h"
 2 #include "ui_mainwindow.h"
 3 
 4 MainWindow::MainWindow(QWidget *parent)
 5     : QMainWindow(parent)
 6     , ui(new Ui::MainWindow)
 7 {
 8     ui->setupUi(this);
 9 
10     setWindowTitle(QStringLiteral("Qt之QVariant的使用分析"));
11 }
12 
13 MainWindow::~MainWindow()
14 {
15     delete ui;
16 }
17 
18 
19 void MainWindow::on_pushButton_2_clicked()
20 {
21     m_pVariant.setValue(5);
22     ui->textEdit->append(QString::number(m_pVariant.toInt()));
23 }
24 
25 void MainWindow::on_pushButton_clicked()
26 {
27     m_pVariant.setValue(QString("aaa"));
28     ui->textEdit->append(m_pVariant.toString());
29 }
30 
31 void MainWindow::on_pushButton_9_clicked()
32 {
33     m_pVariant.setValue(1.1);
34     ui->textEdit->append(QString::number(m_pVariant.toDouble()));
35 }
36 
37 void MainWindow::on_pushButton_10_clicked()
38 {
39     ui->textEdit->append(QStringLiteral("太TM多了，你自己一个一个试吧！"));
40 }
41 
42 void MainWindow::on_pushButton_4_clicked()
43 {
44     if (m_pVariant.isNull())
45         ui->textEdit->append("Null");
46     else
47         ui->textEdit->append("NoNull");
48 }
49 
50 void MainWindow::on_pushButton_3_clicked()
51 {
52     m_pVariant.setValue(QString("12hf6"));
53     if (m_pVariant.convert(QMetaType::Int))
54         ui->textEdit->append("Int");
55     else
56         ui->textEdit->append("NoInt");
57 }
58 
59 void MainWindow::on_pushButton_11_clicked()
60 {
61     m_pVariant.setValue(QString("12hf6"));
62     if (m_pVariant.canConvert(QMetaType::Int))
63         ui->textEdit->append("Int");
64     else
65         ui->textEdit->append("NoInt");
66 }
67 
68 void MainWindow::on_pushButton_6_clicked()
69 {
70     m_pVariant.clear();
71 }
72 
73 void MainWindow::on_pushButton_12_clicked()
74 {
75     if (m_pVariant.isValid())
76         ui->textEdit->append("true");
77     else
78         ui->textEdit->append("false");
79 }
80 
81 void MainWindow::on_pushButton_5_clicked()
82 {
83     ui->textEdit->append(QString::number(m_pVariant.type()));
84 }
85 
86 void MainWindow::on_pushButton_13_clicked()
87 {
88     ui->textEdit->append(m_pVariant.typeName());
89 }
90 
91 void MainWindow::on_pushButton_14_clicked()
92 {
93     ui->textEdit->append(QString::number(m_pVariant.userType()));
94 }
View Code

mainwindow.ui

  1 <?xml version="1.0" encoding="UTF-8"?>
  2 <ui version="4.0">
  3  <class>MainWindow</class>
  4  <widget class="QMainWindow" name="MainWindow">
  5   <property name="geometry">
  6    <rect>
  7     <x>0</x>
  8     <y>0</y>
  9     <width>657</width>
 10     <height>315</height>
 11    </rect>
 12   </property>
 13   <property name="windowTitle">
 14    <string>MainWindow</string>
 15   </property>
 16   <widget class="QWidget" name="centralwidget">
 17    <layout class="QHBoxLayout" name="horizontalLayout">
 18     <item>
 19      <layout class="QVBoxLayout" name="verticalLayout">
 20       <item>
 21        <widget class="QTextEdit" name="textEdit"/>
 22       </item>
 23       <item>
 24        <layout class="QHBoxLayout" name="horizontalLayout_2">
 25         <item>
 26          <widget class="QPushButton" name="pushButton_2">
 27           <property name="text">
 28            <string>增加元素Int</string>
 29           </property>
 30          </widget>
 31         </item>
 32         <item>
 33          <widget class="QPushButton" name="pushButton">
 34           <property name="text">
 35            <string>增加元素QString</string>
 36           </property>
 37          </widget>
 38         </item>
 39         <item>
 40          <widget class="QPushButton" name="pushButton_9">
 41           <property name="text">
 42            <string>增加元素double </string>
 43           </property>
 44          </widget>
 45         </item>
 46         <item>
 47          <widget class="QPushButton" name="pushButton_10">
 48           <property name="text">
 49            <string>更多...</string>
 50           </property>
 51          </widget>
 52         </item>
 53        </layout>
 54       </item>
 55       <item>
 56        <layout class="QHBoxLayout" name="horizontalLayout_3">
 57         <item>
 58          <widget class="QPushButton" name="pushButton_4">
 59           <property name="text">
 60            <string>判断空</string>
 61           </property>
 62          </widget>
 63         </item>
 64         <item>
 65          <widget class="QPushButton" name="pushButton_12">
 66           <property name="text">
 67            <string>是否有效</string>
 68           </property>
 69          </widget>
 70         </item>
 71         <item>
 72          <widget class="QPushButton" name="pushButton_3">
 73           <property name="text">
 74            <string>判断类型(严格)</string>
 75           </property>
 76          </widget>
 77         </item>
 78         <item>
 79          <widget class="QPushButton" name="pushButton_11">
 80           <property name="text">
 81            <string>判断类型(宽松)</string>
 82           </property>
 83          </widget>
 84         </item>
 85        </layout>
 86       </item>
 87       <item>
 88        <layout class="QHBoxLayout" name="horizontalLayout_4">
 89         <item>
 90          <widget class="QPushButton" name="pushButton_6">
 91           <property name="text">
 92            <string>清空</string>
 93           </property>
 94          </widget>
 95         </item>
 96         <item>
 97          <widget class="QPushButton" name="pushButton_5">
 98           <property name="text">
 99            <string>返回类型</string>
100           </property>
101          </widget>
102         </item>
103         <item>
104          <widget class="QPushButton" name="pushButton_13">
105           <property name="text">
106            <string>返回类型名</string>
107           </property>
108          </widget>
109         </item>
110         <item>
111          <widget class="QPushButton" name="pushButton_14">
112           <property name="text">
113            <string>返回使用类型</string>
114           </property>
115          </widget>
116         </item>
117        </layout>
118       </item>
119      </layout>
120     </item>
121    </layout>
122   </widget>
123  </widget>
124  <resources/>
125  <connections/>
126 </ui>
View Code

 

 

 

 

posted on 2022-06-27 18:28  疯狂delphi  阅读(36)  评论(0)  编辑  收藏  举报

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