如何在 QT/QML 中创建共享库 [英] How create shared library in QT/QML

问题描述

我有 4 个 qml 文件和一个 main.cpp 来加载 qml 文件.我是否可以为这 4 个 qml 文件创建 1 个 dll 文件.并在不同的应用程序中使用它，如果可以的话怎么做.

I have 4 qml files and one main.cpp to load qml file. Is it possible for me to create 1 dll file for those 4 qml file. And use it in different application if so how to do that.

推荐答案

如前所述，没有必要只在库中嵌入 qml 文件.但当然，你有权做任何你想做的事，即便如此.我知道至少有两种方法可以做到这一点:

As already said, there is no need for embedding qml files only in a library. But of course you have the right to do all you want, even that. I know at least 2 ways to do that:

1.创建二进制资源文件
准备包含qml文件的资源文件，然后编译:

1. Create binary resource file
Prepare resource file containing qml files and then compile it:

rcc -binary plugin.qrc -o plugin.rcc

现在您可以将此文件包含到您的应用程序中:

Now you can include this file into your application :

QResource::registerResource("plugin.rcc");

并将其用作常规 qrc 文件:

and use it as regular qrc file:

QResource::registerResource(qApp->applicationDirPath() + "/plugin.rcc");
QQuickView *view = new QQuickView();
view->setSource(QUrl("qrc:/qml/myfile.qml"));

这里 qml/ 是资源文件中的前缀.

Here qml/ is prefix in resource file.

<强>2.共享库
另一种方法是创建一个包含相同资源文件的共享库.例如您的插件的共享库实现了以下接口:

2. Shared library
Another way is to create a shared library containing the same resource file. For example your plugin's shared library implements following interface:

interface.h

#ifndef PLUGIN_INTERFACE_H
#define PLUGIN_INTERFACE_H

#include <QString>
#include <QObject>

class PluginInterface
{
public:
    virtual ~PluginInterface() {}
    virtual QByteArray getQML(const QString &name) = 0;
};

#define PluginInterface_iid "org.qt-project.PluginInterface"

Q_DECLARE_INTERFACE(PluginInterface, PluginInterface_iid)

#endif

它的实现是:

QByteArray PluginImpl::getQML(const QString &name)
{
    QFile file(":/qml/" + name);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
        return QByteArray();
    return file.readAll();
}

现在，在您的应用程序中加载您的插件并将其资源作为字符串获取:

Now, in your application you load your plugin and get its resource as a string:

QDir pluginsDir(qApp->applicationDirPath());
QPluginLoader pluginLoader(pluginsDir.absoluteFilePath("plugin.dll"));
QObject *plugin = pluginLoader.instance();
if (plugin) {
    PluginInterface *pluginInstance = qobject_cast<PluginInterface *>(plugin);
    if (pluginInstance) {
        QByteArray content = pluginInstance->getQML("file1.qml");
        QQuickView *view = new QQuickView();
        QQmlComponent component(view->engine());
        component.setData(content, QUrl());
        QQuickItem *childItem = qobject_cast<QQuickItem*>(component.create());
        childItem->setParentItem(view->contentItem());

        QWidget *container = QWidget::createWindowContainer(view);
        container->setFocusPolicy(Qt::TabFocus);
        ui->verticalLayout->addWidget(container);
    }
}

但是请注意，当您部署应用程序时，您无论如何都必须复制所有 qml 系统文件，例如 #QTPATH/qml/QtQml、#QTPATH/qml/QtQuick.2、#QTPATH/qml/QtQuick.2等等

链接:

• 资源编译器
• 相同主题
• 插件示例

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