qt - Component.onCompleted 在包含多个项目的 QML 文件中的顺序是什么？

Question

例如，考虑下面的代码:

Rectangle {
    id: idRectParent

    Rectangle {
        id: idRectChild1
        component.onCompleted: {
            console.log("Iam Child 1")
        }
    }

    Rectangle {
        id: idRectChild2
        component.onCompleted: {
            console.log("Iam Child 2")
        }
    }

    component.onCompleted : {
        console.log("Iam parent Rect")
    }
}

如果我在 qmlscene 中运行它，我会得到下面的输出(我已经尝试了近 50 次)。

Iam parent Rect
Iam Child 2
Iam Child 1

为什么按照上面的顺序输出，而不是:

Iam parent Rect
Iam Child 1
Iam Child 2

或者

Iam Child 1
Iam Child 2
Iam parent Rect

或任何其他组合。

Answer 1

订单未定义:

Emitted after component "startup" has completed. This can be used to execute script code at startup, once the full QML environment has been established.

The corresponding handler is onCompleted. It can be declared on any object. The order of running the onCompleted handlers is undefined.

http://qt-project.org/doc/qt-5/qml-qtqml-component.html#completed-signal