在运行时动态更改 QML 主题 [英] Dynamically change QML theme at runtime

问题描述

我实际上正在使用此处提供的解决方案:https://stackoverflow.com/a/25864815/2425044

I'm actually using the solution provided here: https://stackoverflow.com/a/25864815/2425044

我想去掉 import "MyTheme.js" as Theme; 语句，以便在运行时动态加载特定主题(通常由用户选择).

I'd like to get rid of the import "MyTheme.js" as Theme; statement in order to dynamically load a specific theme at runtime (usually chosen by the user).

我目前正在做的是将我的每个 Themes.js 文件加载到一个 qrc 文件中:

What I'm currently doing is loading each of my Themes.js files in a qrc file:

• redTheme.qrc 包含 Theme.js
• blueTheme.qrc 包含 Theme.js

• redTheme.qrc contains Theme.js
• blueTheme.qrc contains Theme.js

这些qrc文件被编译成外部二进制资源(rcc)并从二进制目录加载，使用

These qrc files are compiled into external binary resources (rcc) and loaded from the binary directory, using

registerResource(const QString &rccFileName, const QString &mapRoot = QString())

到目前为止，一切正常.唯一的问题是我在我的 QML 文件中遇到了 import 语句:

So far, everything works. The only problem is that I'm stuck with an import statement in my QML files:

import "qrc:/redTheme/Theme.js" as Theme

因此，尽管将blueTheme.rcc 注册为资源，但它永远不会被使用.

Thus, despite registeringblueTheme.rcc as a resource, it will never be used.

推荐答案

多亏了其他线程，我才能让它工作.

I was able to make it work, thanks to other threads.

首先，像这个用户一样创建你的主题，它继承自 AbstractStyle，提供更大的灵活性.

First off, create your themes like this user does, which inherit from AbstractStyle, allowing much more flexibility.

https://stackoverflow.com/a/25866188/2425044

我们的 property 将由 JS 函数返回的值定义:

Our property will then be defined by the value returned by a JS function:

import "qrc:/graphics/componentCreation.js" as Theme

Item
{
    id: homeViewItem
    anchors.centerIn: parent

    // Load default theme at startup
    property AbstractTheme currentTheme: Theme.createThemeObject(homeViewItem, "qrc:/redTheme/redTheme.qml");

    Rectangle 
    {
        color: currentTheme.textColorStandard;
    }
}

componentCreation.js

// Create themes components and load them in the apps' QML files

var component;
var sprite;

function createThemeObject(item, themePath)
{
    component = Qt.createComponent(themePath);
    sprite = component.createObject(item);

    if (sprite === null)
        console.log("componentCreation.js: error creating " + themePath + " object");
    else
        return sprite;
}

假设您想在用户点击 Button 时更改主题:

Let's say you want to change theme when the user clicks on a Button:

Button
{
    id: themeButton
    text: "Change to blue theme"
    onClicked:
    {
        // Remove content of redTheme.rcc, register blueTheme.rcc
        cpp_class.changeTheme("redTheme", "blueTheme")
        // blueTheme's content is now available, let's fill its content into a QML object
        currentTheme = Theme.createThemeObject(homeViewItem, "qrc:/blueTheme/blueTheme.qml")
    }
}

记住，redTheme.qml 和 blueTheme.qml 包含在 qrc 文件中，这些文件本身被编译成 rcc 文件.

Remember, redTheme.qml and blueTheme.qml are contained in qrc files which are themselves compiled into rcc files.

这是changeTheme(const QString&, const QString&)的定义，它注销旧主题并注册新主题:

Here's the definition of changeTheme(const QString&, const QString&), which unregisters the old theme and registers the new one:

void cpp_class::changeTheme(const QString &oldTheme, const QString &newTheme)
{
    bool un = QResource::unregisterResource(QCoreApplication::applicationDirPath() + "/data/themes/" + app + "/" + oldTheme + ".rcc");
    if (!un)
        std::cerr << oldTheme.toStdString() << "could not be unregistered" << std::endl;
    bool in = QResource::registerResource(QCoreApplication::applicationDirPath() + "/data/themes/" + app + "/" + newTheme + ".rcc");
    if (!in)
        std::cerr << newTheme.toStdString() << "could not be registered as an external binary resource" << std::endl;
}

其他对我有帮助的主题:

Other threads that have helped me:

https://wiki.qt.io/Qml_Styling

http://www.slideshare.net/BurkhardStubert/practical-qml-key-navigation(从幻灯片 34 开始)

http://www.slideshare.net/BurkhardStubert/practical-qml-key-navigation (begins at slide 34)

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