ListElement QML 类型

import 语句：

import QtQml.Models 2.2

所有成员列表，包括继承成员

详细描述

List elements are defined inside ListModel definitions, and represent items in a list that will be displayed using ListView or Repeater 项。

List elements are defined like other QML elements except that they contain a collection of role definitions instead of properties. Using the same syntax as property definitions, roles both define how the data is accessed and include the data itself.

The names used for roles must begin with a lower-case letter and should be common to all elements in a given model. Values must be simple constants; either strings (quoted and optionally within a call to QT_TR_NOOP ), boolean values (true, false), numbers, or enumeration values (such as AlignText.AlignHCenter).

Beginning with Qt 5.11 ListElement also allows assigning a function declaration to a role. This allows the definition of ListElements with callable actions.

引用角色

The role names are used by delegates to obtain data from list elements. Each role name is accessible in the delegate's scope, and refers to the corresponding role in the current element. Where a role name would be ambiguous to use, it can be accessed via the model property (e.g., model.cost 而不是 cost ).

用法范例

The following model defines a series of list elements, each of which contain "name" and "cost" roles and their associated values.

ListModel {
    id: fruitModel
    ListElement {
        name: "Apple"
        cost: 2.45
    }
    ListElement {
        name: "Orange"
        cost: 3.25
    }
    ListElement {
        name: "Banana"
        cost: 1.95
    }
}

The delegate obtains the name and cost for each element by simply referring to 名称 and cost :

ListView {
    anchors.fill: parent
    model: fruitModel
    delegate: Row {
        Text { text: "Fruit: " + name }
        Text { text: "Cost: $" + cost }
    }
}

另请参阅 ListModel .