PropertyAction QML Type

Specifies immediate property changes during animation. 更多...

导入语句：	import QtQuick 2.12
继承：	动画

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特性

exclude : list<Object>
properties : string
property : string
target : Object
targets : list<Object>
value : any

详细描述

PropertyAction is used to specify an immediate property change during an animation. The property change is not animated.

It is useful for setting non-animated property values during an animation.

For example, here is a SequentialAnimation that sets the image's opacity 特性到 .5 , animates the width of the image, then sets opacity back to 1 :

SequentialAnimation {
    PropertyAction { target: img; property: "opacity"; value: .5 }
    NumberAnimation { target: img; property: "width"; to: 300; duration: 1000 }
    PropertyAction { target: img; property: "opacity"; value: 1 }
}

PropertyAction is also useful for setting the exact point at which a property change should occur during a Transition . For example, if PropertyChanges was used in a State to rotate an item around a particular transformOrigin , it might be implemented like this:

Item {
    width: 400; height: 400
    Rectangle {
        id: rect
        width: 200; height: 100
        color: "red"
        states: State {
            name: "rotated"
            PropertyChanges { target: rect; rotation: 180; transformOrigin: Item.BottomRight }
        }
        transitions: Transition {
            RotationAnimation { duration: 1000; direction: RotationAnimation.Counterclockwise }
        }
        MouseArea {
            anchors.fill: parent
            onClicked: rect.state = "rotated"
        }
    }
}

However, with this code, the transformOrigin is not set until after the animation, as a State is taken to define the values at the end of a transition. The animation would rotate at the default transformOrigin , then jump to Item.BottomRight . To fix this, insert a PropertyAction before the RotationAnimation begins:

transitions: Transition {
    SequentialAnimation {
        PropertyAction { target: rect; property: "transformOrigin" }
        RotationAnimation { duration: 1000; direction: RotationAnimation.Counterclockwise }
    }
}

This immediately sets the transformOrigin property to the value defined in the end state of the Transition (i.e. the value defined in the PropertyAction object) so that the rotation animation begins with the correct transform origin.

另请参阅 Qt Quick 中的动画和过渡 and Qt QML .

特性文档编制

exclude : list < Object >

This property holds the objects that should not be affected by this action.

另请参阅 targets .

properties : string

These properties determine the items and their properties that are affected by this action.

The details of how these properties are interpreted in different situations is covered in the corresponding PropertyAnimation 文档编制。

另请参阅 exclude .

property : string

These properties determine the items and their properties that are affected by this action.

The details of how these properties are interpreted in different situations is covered in the corresponding PropertyAnimation 文档编制。

另请参阅 exclude .

target : Object

These properties determine the items and their properties that are affected by this action.

The details of how these properties are interpreted in different situations is covered in the corresponding PropertyAnimation 文档编制。

另请参阅 exclude .

targets : list < Object >

These properties determine the items and their properties that are affected by this action.

The details of how these properties are interpreted in different situations is covered in the corresponding PropertyAnimation 文档编制。

另请参阅 exclude .

value : any

This property holds the value to be set on the property.

若 PropertyAction is defined within a Transition or 行为 , this value defaults to the value defined in the end state of the Transition , or the value of the property change that triggered the 行为 .