list QML Basic Type

The list type refers to a list of QML objects.

A list value can be accessed in a similar way to a JavaScript array:

  • Values are assigned using the [] square bracket syntax with comma-separated values
  • The length property provides the number of items in the list
  • Values in the list are accessed using the [index] syntax

Values can be dynamically added to the list by using the push method, as if it were a JavaScript Array

A list can only store QML objects, and cannot contain any 基本类型 values. (To store basic types within a list, use the var type instead.)

When integrating with C++, note that any QQmlListProperty passed into QML from C++ is automatically converted into a list value, and vice-versa.

Using the list Type

例如, Item 类型拥有 states list-type property that can be assigned to and used as follows:

import QtQuick 2.0
Item {
    width: 100; height: 100
    states: [
        State { name: "activated" },
        State { name: "deactivated" }
    ]
    Component.onCompleted: {
        console.log("Name of first state:", states[0].name)
        for (var i = 0; i < states.length; i++)
            console.log("state", i, states[i].name)
    }
}
					

The defined State objects will be added to the 状态 list in the order in which they are defined.

If the list only contains one object, the square brackets may be omitted:

import QtQuick 2.0
Item {
    width: 100; height: 100
    states: State { name: "activated" }
}
					

Note that objects cannot be individually added to or removed from the list once created; to modify the contents of a list, it must be reassigned to a new list.

注意: The list type is not recommended as a type for custom properties. The var type should be used instead for this purpose as lists stored by the var type can be manipulated with greater flexibility from within QML.

此基本类型由 QML 语言提供。

另请参阅 QML 基本类型 .