Circular dial that is rotated to set a value. 更多...
导入语句: | import QtQuick.Controls 2.2 |
Since: | Qt 5.7 |
继承: | Control |
The Dial is similar to a traditional dial knob that is found on devices such as stereos or industrial equipment. It allows the user to specify a value within a range.
The value of the dial is set with the value property. The range is set with the from and to properties. To enable or disable wrapping, use the wrap 特性。
The dial can be manipulated with a keyboard. It supports the following actions:
动作 | Key |
---|---|
Decrease value by stepSize |
Qt.Key_Left
|
Decrease value by stepSize |
Qt.Key_Down
|
Set value to from |
Qt.Key_Home
|
Increase value by stepSize |
Qt.Key_Right
|
Increase value by stepSize |
Qt.Key_Up
|
Set value to to |
Qt.Key_End
|
Dial supports three
input modes
:
Dial.Circular
,
Dial.Horizontal
and
Dial.Vertical
. The circular input mode operates on an absolute input system, where the position of the cursor within the dial directly reflects its value. The horizontal and vertical input modes use a relative input system, where changes in the cursor's position are "added" to the value of the dial.
The following image illustrates the directions in which the various input modes track movement:
另请参阅 Customizing Dial and 输入控件 .
[read-only] angle : real |
This property holds the angle of the handle.
The range is from
-140
degrees to
140
度。
另请参阅 position .
from : real |
This property holds the starting value for the range. The default value is
0.0
.
handle : Item |
This property holds the handle of the dial.
The handle acts as a visual indicator of the position of the dial.
另请参阅 Customizing Dial .
[since QtQuick.Controls 2.5 (Qt 5.12)] inputMode : enumeration |
This property holds the input mode.
Dial supports three input modes:
Dial.Circular
,
Dial.Horizontal
and
Dial.Vertical
. The circular input mode operates on an absolute input system, where the position of the cursor within the dial directly reflects its value. The horizontal and vertical input modes use a relative input system, where changes in the cursor's position are "added" to the value of the dial.
The following image illustrates the directions in which the various input modes track movement:
默认值为
Dial.Circular
.
该特性在 QtQuick.Controls 2.5 (Qt 5.12) 引入。
[since QtQuick.Controls 2.2 (Qt 5.9)] live : bool |
This property holds whether the dial provides live updates for the value property while the handle is dragged.
默认值为
true
.
This property was introduced in QtQuick.Controls 2.2 (Qt 5.9).
另请参阅 value .
[read-only] position : real |
This property holds the logical position of the handle.
The position is expressed as a fraction of the control's angle range (the range within which the handle can be moved) in the range
0.0 - 1.0
.
pressed : bool |
This property holds whether the dial is pressed.
The dial will be pressed when either the mouse is pressed over it, or a key such as
Qt.Key_Left
is held down. If you'd prefer not to have the dial be pressed upon key presses (due to styling reasons, for example), you can use the
Keys attached property
:
Dial {
Keys.onLeftPressed: {}
}
This will result in pressed only being
true
upon mouse presses.
snapMode : enumeration |
This property holds the snap mode.
The snap mode works with the stepSize to allow the handle to snap to certain points along the dial.
可能的值:
常量 | 描述 |
---|---|
Dial.NoSnap
|
The dial does not snap (default). |
Dial.SnapAlways
|
The dial snaps while the handle is dragged. |
Dial.SnapOnRelease
|
The dial does not snap while being dragged, but only after the handle is released. |
另请参阅 stepSize .
stepSize : real |
This property holds the step size.
The step size determines the amount by which the dial's value is increased and decreased when interacted with via the keyboard. For example, a step size of
0.2
, will result in the dial's value increasing and decreasing in increments of
0.2
.
The step size is only respected for touch and mouse interaction when
snapMode
is set to a value other than
Dial.NoSnap
.
默认值为
0.0
, which results in an effective step size of
0.1
for keyboard interaction.
另请参阅 snapMode , increase() ,和 decrease() .
to : real |
This property holds the end value for the range. The default value is
1.0
.
value : real |
This property holds the value in the range
from
-
to
。默认值为
0.0
.
wrap : bool |
This property holds whether the dial wraps when dragged.
For example, when this property is set to
true
, dragging the dial past the
to
position will result in the handle being positioned at the
from
position, and vice versa:
When this property is
false
, it's not possible to drag the dial across the from and to values.
默认值为
false
.
[since QtQuick.Controls 2.2 (Qt 5.9)]
moved
()
|
This signal is emitted when the dial has been interactively moved by the user by either touch, mouse, or keys.
注意:
相应处理程序是
onMoved
.
This signal was introduced in QtQuick.Controls 2.2 (Qt 5.9).
void decrease () |
Decreases the value by
stepSize
,或
0.1
if
stepSize
is not defined.
另请参阅 stepSize .
void increase () |
Increases the value by
stepSize
,或
0.1
if
stepSize
is not defined.
另请参阅 stepSize .