采用视图呈现数据

Views are containers for collections of items. They are feature-rich and can be customizable to meet style or behavior requirements.

A set of standard views are provided in the basic set of Qt Quick graphical elements:

ListView arranges items in a horizontal or vertical list
GridView arranges items in a grid within the available space
PathView arranges items on a path
WebView - available from the QtWebKit QML 模块 .

Unlike other views, WebView is not a fully-featured view item, and needs to be combined with a Flickable item to create a view that performs like a Web browser.

These elements have properties and behaviors exclusive to each element. Visit their respective documentation for more information.

模型

Views display models onto the screen. A model could be a simple list of integer 或 C++ model .

To assign a model to a view, bind the view's model property to a model.

ListModel {
    id: petlist
    ListElement { type: "Cat" }
    ListElement { type: "Dog" }
    ListElement { type: "Mouse" }
    ListElement { type: "Rabbit" }
    ListElement { type: "Horse" }
}
ListView {
    id: view
    anchors.fill: parent
    model: petlist
    delegate: petdelegate
}

更多信息，请翻阅 QML Data Models article.

视图委托

Views need a delegate to visually represent an item in a list. A view will visualize each item list according to the template defined by the delegate. Items in a model are accessible through the index property as well as the item's properties.

Component {
    id: petdelegate
    Text {
        id: label
        font.pixelSize: 24
        text: if (index == 0)
            label.text = type + " (default)"
        else
            text: type
    }
}

Decorating Views

Views allow visual customization through decoration properties such as the header , footer ，和 section properties. By binding an object, usually another visual object, to these properties, the views are decoratable. A footer may include a Rectangle element showcasing borders or a header that displays a logo on top of the list.

Suppose that a specific club wants to decorate its members list with its brand colors. A member list is in a model 和 delegate will display the model's content.

ListModel {
    id: nameModel
    ListElement { name: "Alice" }
    ListElement { name: "Bob" }
    ListElement { name: "Jane" }
    ListElement { name: "Harry" }
    ListElement { name: "Wendy" }
}
Component {
    id: nameDelegate
    Text {
        text: name;
        font.pixelSize: 24
    }
}

The club may decorate the members list by binding visual objects to the header and footer properties. The visual object may be defined inline, in another file, or in a Component 元素。

ListView {
    anchors.fill: parent
    clip: true
    model: nameModel
    delegate: nameDelegate
    header: bannercomponent
    footer: Rectangle {
        width: parent.width; height: 30;
        gradient: clubcolors
    }
    highlight: Rectangle {
        width: parent.width
        color: "lightgray"
    }
}
Component {     //instantiated when header is processed
    id: bannercomponent
    Rectangle {
        id: banner
        width: parent.width; height: 50
        gradient: clubcolors
        border {color: "#9EDDF2"; width: 2}
        Text {
            anchors.centerIn: parent
            text: "Club Members"
            font.pixelSize: 32
        }
    }
}
Gradient {
    id: clubcolors
    GradientStop { position: 0.0; color: "#8EE2FE"}
    GradientStop { position: 0.66; color: "#7ED2EE"}
}

ListView Sections

ListView contents may be grouped into sections , where related list items are labeled according to their sections. Further, the sections may be decorated with delegates .

A list may contain a list indicating people's names and the team on which team the person belongs.

ListModel {
    id: nameModel
    ListElement { name: "Alice"; team: "Crypto" }
    ListElement { name: "Bob"; team: "Crypto" }
    ListElement { name: "Jane"; team: "QA" }
    ListElement { name: "Victor"; team: "QA" }
    ListElement { name: "Wendy"; team: "Graphics" }
}
Component {
    id: nameDelegate
    Text {
        text: name;
        font.pixelSize: 24
        anchors.left: parent.left
        anchors.leftMargin: 2
    }
}

The ListView element has the section attached property that can combine adjacent and related elements into a section. The section's property property is for selecting which list element property to use as sections. The criteria can dictate how the section names are displayed and the delegate is similar to the views' delegate 特性。

ListView {
    anchors.fill: parent
    model: nameModel
    delegate: nameDelegate
    focus: true
    highlight: Rectangle {
        color: "lightblue"
        width: parent.width
    }
    section {
        property: "team"
        criteria: ViewSection.FullString
        delegate: Rectangle {
            color: "#b0dfb0"
            width: parent.width
            height: childrenRect.height + 4
            Text { anchors.horizontalCenter: parent.horizontalCenter
                font.pixelSize: 16
                font.bold: true
                text: section
            }
        }
    }
}