内容

• 特性
• 详细描述

DragHandler QML Type

Handler for dragging. 更多...

import 语句：	import QtQuick 2.12
继承：	MultiPointHandler

• 所有成员列表，包括继承成员

特性

• translation : QVector2D
• xAxis
  • xAxis.minimum : real
  • xAxis.maximum : real
  • xAxis.enabled : bool
• yAxis
  • yAxis.minimum : real
  • yAxis.maximum : real
  • yAxis.enabled : bool

详细描述

DragHandler is a handler that is used to interactively move an Item. Like other Input Handlers, by default it is fully functional, and manipulates its target .

import QtQuick 2.12
Rectangle {
    width: 100
    height: 100
    color: "lightsteelblue"
    DragHandler { }
}
					

It has properties to restrict the range of dragging.

If it is declared within one Item but is assigned a different target , then it handles events within the bounds of the parent Item but manipulates the target Item instead:

import QtQuick 2.12
Item {
    width: 640
    height: 480
    Rectangle {
        id: feedback
        border.color: "red"
        width: Math.max(10, handler.centroid.ellipseDiameters.width)
        height: Math.max(10, handler.centroid.ellipseDiameters.height)
        radius: Math.max(width, height) / 2
        visible: handler.active
    }
    DragHandler {
        id: handler
        target: feedback
    }
}
					

A third way to use it is to set target to null and react to property changes in some other way:

import QtQuick 2.12
Item {
    width: 640
    height: 480
    DragHandler {
        id: handler
        target: null
    }
    Text {
        color: handler.active ? "darkgreen" : "black"
        text: handler.centroid.centroid.x.toFixed(1) + "," + handler.centroid.position.y.toFixed(1)
        x: handler.centroid.position.x - width / 2
        y: handler.centroid.position.y - height
    }
}
					

If minimumPointCount and maximumPointCount are set to values larger than 1, the user will need to drag that many fingers in the same direction to start dragging. A multi-finger drag gesture can be detected independently of both a (default) single-finger DragHandler 和 PinchHandler on the same Item, and thus can be used to adjust some other feature independently of the usual pinch behavior: for example adjust a tilt transformation, or adjust some other numeric value, if the target is set to null. But if the target is an Item, centroid is the point at which the drag begins and to which the target will be moved (subject to constraints).

At this time, drag-and-drop is not yet supported.

另请参阅 Drag and MouseArea .

特性文档编制

[read-only] translation : QVector2D

The translation since the gesture began.

xAxis group
xAxis.minimum : real
xAxis.maximum : real
xAxis.enabled : bool

xAxis controls the constraints for horizontal dragging.

minimum is the minimum acceptable value of x to be applied to the target . maximum is the maximum acceptable value of x to be applied to the target 。若 被启用 is true, horizontal dragging is allowed.

yAxis group
yAxis.minimum : real
yAxis.maximum : real
yAxis.enabled : bool

yAxis controls the constraints for vertical dragging.

minimum is the minimum acceptable value of y to be applied to the target . maximum is the maximum acceptable value of y to be applied to the target 。若 被启用 is true, vertical dragging is allowed.