QT插件简单使用2

1 总的目录结构

2 主程序

3 插件程序

4 运行结果

相比原来的QT插件简单使用-CSDN博客增加了

         QObject *create(const QString &name, const QString &spec) override;

函数的使用和Plugin.json的使用

1 总的目录结构

编译器mingw-64

2 主程序

1 新建一个其他项目的子文件目录后，创建一个普通的 QMainWindow 项目

主程序中添加头文件 Interface.h 内容如下：

#ifndef INTERFACE_H
#define INTERFACE_H
#include <QGenericPlugin>
#include <QtPlugin>
//定义接口
class Interface : public QObject
{Q_OBJECT
public:virtual ~Interface() {}virtual int add(int a,int b) = 0;
};QT_BEGIN_NAMESPACE
Q_DECLARE_INTERFACE(Interface, "org.qt-project.Qt.QGenericPluginFactoryInterface")
QT_END_NAMESPACE#endif // INTERFACE_H

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include "interface.h"
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();void LoadPlugin();Interface* m_pInterface = nullptr;
private slots:void on_pushButton_clicked();private:Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

mainwindow.cpp

void MainWindow::LoadPlugin()
{QString filename = qApp->applicationDirPath() + "/Plugin.dll";qDebug()<<"LoadPlugin filename:"<<filename;QPluginLoader pluginLoader(filename);QGenericPlugin *plugin = qobject_cast<QGenericPlugin *>(pluginLoader.instance());if (plugin) {// 使用 QGenericPlugin 的 create 函数来创建插件对象QObject *pluginInstance = plugin->create("pluginA", "");if (pluginInstance){// 尝试转换插件对象为MyPlugin类型Interface *myPlugin = qobject_cast<Interface *>(pluginInstance);qDebug()<<"LoadPlugin success! "<<myPlugin->add(112,1);// 获取插件的元数据信息（如果有的话）QJsonObject metaData = pluginLoader.metaData();QJsonObject jsonObject = metaData.value("MetaData").toObject();QJsonObject obj = jsonObject.value("MetaData").toObject();QString version = obj.value("Version").toString();QString Name = obj.value("Name").toString();QString Description = obj.value("Description").toString();QString Class = obj.value("Class").toString();QString Author = obj.value("Author").toString();QString License = obj.value("License").toString();qDebug()<<version;qDebug()<<Name;qDebug()<<Description;qDebug()<<Class;qDebug()<<Author;qDebug()<<License;return ;}elseqDebug()<<"qobject_cast fail!";}else{QMessageBox::warning(0,"warning","LoadPlugin fail!");qDebug()<<"LoadPlugin fail!";}}

3 插件程序

1 右击主项目新建子项目项

（也可以新建另一个工程）

选择C++ Library ---->QT Plugin

将 Interface.h拷贝到该目录下与Plugin.pro同级目录

genericplugin.h

#ifndef GENERICPLUGIN_H
#define GENERICPLUGIN_H#include <QGenericPlugin>
#include "Interface.h"
class GenericPlugin : public QGenericPlugin
{Q_OBJECTQ_PLUGIN_METADATA(IID "org.qt-project.Qt.QGenericPluginFactoryInterface/1.0" FILE "Plugin.json")public:explicit GenericPlugin(QObject *parent = nullptr);private:QObject *create(const QString &name, const QString &spec) override;
};#endif // GENERICPLUGIN_H

genericplugin.cpp

#include "genericplugin.h"
#include "plugina.h"
#include "pluginb.h"GenericPlugin::GenericPlugin(QObject *parent): QGenericPlugin(parent)
{}QObject *GenericPlugin::create(const QString &name, const QString &spec)
{static_assert(true, "You need to implement this function");if(name == "pluginA")return new pluginA();if(name == "pluginB")return new pluginB();return nullptr;
}

plugina.h

#ifndef PLUGINA_H
#define PLUGINA_H#include <QObject>
#include "Interface.h"
class pluginA : public Interface
{Q_OBJECTQ_INTERFACES(Interface)
public:pluginA();int add(int a,int b) override;
};#endif // PLUGINA_H

plugina.cpp

#include "plugina.h"pluginA::pluginA()
{}int pluginA::add(int a, int b)
{return 11;
}

pluginb.h

#ifndef PLUGINB_H
#define PLUGINB_H#include <QObject>
#include "Interface.h"
class pluginB : public Interface
{Q_OBJECTQ_INTERFACES(Interface)
public:pluginB();int add(int a,int b) override;
};#endif // PLUGINB_H

pluginb.cpp

#include "pluginb.h"pluginB::pluginB()
{}int pluginB::add(int a, int b)
{return 12;
}

Plugin.json

{"MetaData": {"Version": "1.0.0","Name": "MyCustomPlugin","Description": "A custom plugin for my application","Class": "MyCustomPluginClass","Author": "Your Name","License": "Some License","Dependencies": {"OtherPlugin": ">=1.2.0"}}
}