StackView:存储组件及其项目 [英] StackView: storing components along with their items

问题描述

考虑以下代码:

StackView {
    id: stack
}

Component {
    id: componentFooBar
    FooBar {}
}
...
stack.push({item: componentFooBar})

在上面的例子中，根据 Qt 源代码和文档，在 componentFooBar 被压入堆栈后，它的内部项 (FooBar) 被加载并压入栈顶内部堆栈.如果我想访问堆栈头(通过 pop() 或 get(0))，我将获得 FooBar 实例，而不是它的 Component.所以对于 Qml StackView 没有像

In the example above, according to the Qt source and documentation, after componentFooBar is pushed to the stack its inner item (FooBar) is loaded and pushed to the top of the inner stack. And if I want to access stack head (either by pop() or get(0)), I'll get FooBar instance, not its Component. So for Qml StackView there's no invariant like

stack.push(X)
X === stack.pop()

有没有办法访问推送的Component?我现在唯一的想法是为 push()/pop()/get() 方法编写一些包装器并存储 Components 在一些单独的堆栈中:

Is there any way to access pushed Components? The only idea I have for now is to write some wrappers for push()/pop()/get() methods and store Components in some separate stack:

StackView {
    property var componentStack: []
    function _push (x) {
        push(x)
        componentStack.push(x)
    }
    function _pop (x) {
        pop(x)
        return componentStack.pop()
    }
}

但对我来说它看起来像一个黑客，而且我有很多使用默认 push()/pop() 方法的代码.还有其他解决办法吗?

But for me it looks like an hack, also I have a lot of code using default push()/pop() methods. Is there any other solution?

推荐答案

1. 创建一个组件数组，例如这里:

1. Create an array of your components, such as here:

StackView {
   id: stackView
}

property variant myObjects: [component1.createObject(), component2.createObject(), component3.createObject()] 

Component {
   id: component1
}

Component {
   id: component2
}

Component {
   id: component3
}

然后在推送到 StackView 时确保使用 destroyOnPop 属性:

Then when pushing to StackView make sure to use destroyOnPop property:

stackView.push({item: myObjects[componentIndex], destroyOnPop: false})

通过执行这两个步骤，StackView 不会获得您的对象的所有权.因此，您可以直接处理对象，并且仍然可以多次推送/弹出 StackView.

By following these two steps, StackView does not take ownership by your objects. Therefore, you can work with objects directly and still push/pop many times to StackView.

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