API level differences between Qt Quick Ultralite and Qt Quick

Many Qt Quick QML types are implemented in Qt Quick Ultralite. The API 参考 covers the available API. If some part of the API is not listed, Qt Quick Ultralite does not currently implement it.

This topic lists particular API differences beyond unimplemented API.

另请参阅 已知问题或局限性 .

Item QML type

Item::parent is read-only. The parent of an Item cannot be changed in states or script expressions.

anchors of an Item cannot be changed in script expressions.

state , states ,和 transitions properties are only available for the root item of a QML file.

visible property does not propagate to children. If a parent's visible 特性为 false , the children will be invisible, but their visible property may be true .

Image QML type

Qt Quick Ultralite implements the transform property on 图像 . In Qt Quick, this property is part of the Item 类型。

ListView QML type

The current implementation of ListView assumes that all delegates have the same size. It is a known bug that you need to provide size for the delegate explicitly.

Text QML type

Qt Quick Ultralite implements two additional Text properties: baselineOffset and transform . In Qt Quick, these properties are part of the Item 类型。

Text has the additional font.unicodeCoverage property. See 文本渲染和字体 了解细节。

Qt Quick Ultralite also implements a StaticText type to optimize text display when the text is known at compile-time.

Conditional availability of the scale, rotation, and transformOrigin properties

The scale, rotation, and transformOrigin properties on the 图像 , Text , StaticText types are generated conditionally. The properties are only available if a binding to them exists.

Image {
    id: img
    source: "logo.png"
    Component.onCompleted: img.scale = 1.5 // error!
    // If this binding is present, the scale property will be available.
    // scale: 1
}