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  2. Qt 6.7.2
  3. Qt Charts
  4. QML 类型
  5. PieSeries

PieSeries QML Type

Presents data in pie charts. 更多...

import 语句： import QtCharts 2.7
实例化： QPieSeries
继承：

AbstractSeries

特性

信号

方法

详细描述

A pie series consists of slices that are defined using the PieSlice type. The slices can have any values as the PieSeries type calculates the percentage of a slice compared with the sum of all slices in the series to determine the actual size of the slice in the chart.

Pie size and position on the chart are controlled by using relative values that range from 0.0 to 1.0. These relate to the actual chart rectangle.

By default, the pie is defined as a full pie. A partial pie can be created by setting a starting angle and angle span for the series. A full pie is 360 degrees, where 0 is at 12 a'clock.

The following QML example shows how to create a simple pie chart. 

ChartView {
    id: chart
    title: "Top-5 car brand shares in Finland"
    anchors.fill: parent
    legend.alignment: Qt.AlignBottom
    antialiasing: true
    property variant othersSlice: 0
    PieSeries {
        id: pieSeries
        PieSlice { label: "Volkswagen"; value: 13.5 }
        PieSlice { label: "Toyota"; value: 10.9 }
        PieSlice { label: "Ford"; value: 8.6 }
        PieSlice { label: "Skoda"; value: 8.2 }
        PieSlice { label: "Volvo"; value: 6.8 }
    }
    Component.onCompleted: {
        // You can also manipulate slices dynamically, like append a slice or set a slice exploded
        othersSlice = pieSeries.append("Others", 52.0);
        pieSeries.find("Volkswagen").exploded = true;
    }
}

另请参阅 PieSlice and ChartView .

特性文档编制

count : int [read-only]

The number of slices in the series.

endAngle : real

The ending angle of the pie.

A full pie is 360 degrees, where 0 degrees is at 12 a'clock.

The default value is 360.

holeSize : real

The donut hole size.

The value is relative to the chart rectangle, so that:

  • 0.0 is the minimum size (full pie drawn without a hole).
  • 1.0 is the maximum size that can fit the chart (the donut has no width).

当设置此特性时， size property is adjusted if necessary, to ensure that the hole size is not greater than the pie size.

The default value is 0.0.

horizontalPosition : real

The horizontal position of the pie.

The value is relative to the chart rectangle, so that:

  • 0.0 is the absolute left.
  • 1.0 is the absolute right.

The default value is 0.5 (center).

另请参阅 verticalPosition .

size : real

The pie size.

The value is relative to the chart rectangle, so that:

  • 0.0 is the minimum size (pie not drawn).
  • 1.0 is the maximum size that can fit the chart.

当设置此特性时， holeSize property is adjusted if necessary, to ensure that the hole size is not greater than the pie size.

The default value is 0.7.

startAngle : real

The starting angle of the pie.

A full pie is 360 degrees, where 0 degrees is at 12 a'clock.

默认值为 0。

sum : real [read-only]

The sum of all slices.

The series keeps track of the sum of all the slices it holds.

verticalPosition : real

The vertical position of the pie.

The value is relative to the chart rectangle, so that:

  • 0.0 is the absolute top.
  • 1.0 is the absolute bottom.

The default value is 0.5 (center).

另请参阅 horizontalPosition .

信号文档编制

添加 ( list < PieSlice > slices )

This signal is emitted when the slices specified by slices are added to the series.

The corresponding signal handler is onAdded .

注意： 相应处理程序是 onAdded .

clicked ( PieSlice slice )

This signal is emitted when the slice specified by slice 被点击。

The corresponding signal handler is onClicked .

注意： 相应处理程序是 onClicked .

doubleClicked ( PieSlice slice )

This signal is emitted when the slice specified by slice is double-clicked.

The corresponding signal handler is onDoubleClicked .

注意： 相应处理程序是 onDoubleClicked .

hovered ( PieSlice slice , bool state )

This signal is emitted when a mouse is hovered over the slice specified by slice . When the mouse moves over the slice, state turns true , and when the mouse moves away again, it turns false .

The corresponding signal handler is onHovered .

注意： 相应处理程序是 onHovered .

pressed ( PieSlice slice )

This signal is emitted when the user clicks the slice specified by slice and holds down the mouse button.

The corresponding signal handler is onPressed .

注意： 相应处理程序是 onPressed .

released ( PieSlice slice )

This signal is emitted when the user releases the mouse press on the slice specified by slice .

The corresponding signal handler is onReleased .

注意： 相应处理程序是 onReleased .

removed ( list < PieSlice > slices )

This signal is emitted when the slices specified by slices are removed from the series.

The corresponding signal handler is onRemoved .

注意： 相应处理程序是 onRemoved .

sliceAdded ( PieSlice slice )

This signal is emitted when the slice specified by slice is added to the series.

The corresponding signal handler is onSliceAdded .

注意： 相应处理程序是 onSliceAdded .

sliceRemoved ( PieSlice slice )

This signal is emitted when the slice specified by slice is removed from the series.

The corresponding signal handler is onSliceRemoved .

注意： 相应处理程序是 onSliceRemoved .

方法文档编制

PieSlice append ( string label , real value )

Adds a new slice with the label label and the value value to the pie.

PieSlice at ( int index )

Returns the slice at the position specified by index . Returns null if the index is not valid.

clear ()

Removes all slices from the pie.

PieSlice find ( string label )

Returns the first slice that has the label label . Returns null if the label is not found.

bool remove ( PieSlice slice )

Removes the slice specified by slice from the pie. Returns true if the removal was successful, false 否则。

内容