IndicatorLeaveEventArgs Class

Provides data for the RangeBase.IndicatorLeave event.

Namespace: DevExpress.Xpf.Gauges

Assembly: DevExpress.Xpf.Gauges.v19.1.dll

Declaration

C#

[NonCategorized]
public class IndicatorLeaveEventArgs :
    IndicatorEnterLeaveEventArgs

VB.NET

<NonCategorized>
Public Class IndicatorLeaveEventArgs
    Inherits IndicatorEnterLeaveEventArgs

Related API Members

IndicatorLeaveEventArgs is the data class for the following events:

• RangeBase.IndicatorLeave

Remarks

The RangeBase.IndicatorLeave event occurs when any value indicator (e.g. needle, level bar, marker or range bar) leaves a particular range.

An instance of the IndicatorLeaveEventArgs class with appropriate settings is automatically created and passed to the corresponding event’s handler.

Example

In some cases, you need to know whether the current value of an indicator is within a particular range. This example shows how to create a state indicator that changes its color depending on the current range.

First, the Circular gauge is created with three ranges and two empty sections. By default, the gauge’s needle doesn’t belong to any range, so the state indicator is painted as a gray ellipse.

To solve this task it’s necessary to handle the RangeBase.IndicatorEnter and RangeBase.IndicatorLeave events in the following way:

- if a needle ‘enters’ a range, it is painted with the range color;

- if a needle ‘leaves’ a range, it is painted in gray.

Note

In this example we set the ValueIndicatorBase.IsInteractive property to True, so that you can click on a gauge and manually change the current needle value.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-determine-whether-an-indicators-value-falls-into-a-particular-range-e3328.

MainWindow.xaml.vb

Imports Microsoft.VisualBasic
Imports System.Windows
Imports System.Windows.Media
Imports DevExpress.Xpf.Gauges

Namespace DXGauges_RangeEvents

    Partial Public Class MainWindow
        Inherits Window
        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub GreenRange_IndicatorEnter(ByVal sender As Object, ByVal e As IndicatorEnterEventArgs)
            stateIndicator.Fill = New SolidColorBrush(Colors.Green)
        End Sub

        Private Sub GreenRange_IndicatorLeave(ByVal sender As Object, ByVal e As IndicatorLeaveEventArgs)
            stateIndicator.Fill = New SolidColorBrush(Colors.Gray)
        End Sub

        Private Sub YellowRange_IndicatorEnter(ByVal sender As Object, ByVal e As IndicatorEnterEventArgs)
            stateIndicator.Fill = New SolidColorBrush(Colors.Yellow)
        End Sub

        Private Sub YellowRange_IndicatorLeave(ByVal sender As Object, ByVal e As IndicatorLeaveEventArgs)
            If ((e.NewValue) < 10) OrElse (((e.NewValue) > 90)) Then
                stateIndicator.Fill = New SolidColorBrush(Colors.Gray)
            End If
        End Sub

        Private Sub RedRange_IndicatorEnter(ByVal sender As Object, ByVal e As IndicatorEnterEventArgs)
            stateIndicator.Fill = New SolidColorBrush(Colors.Red)
        End Sub

        Private Sub RedRange_IndicatorLeave(ByVal sender As Object, ByVal e As IndicatorLeaveEventArgs)
            If ((e.NewValue) < 10) OrElse (((e.NewValue) > 90)) Then
                stateIndicator.Fill = New SolidColorBrush(Colors.Gray)
            End If
        End Sub
    End Class
End Namespace

MainWindow.xaml

<Window x:Class="DXGauges_RangeEvents.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:dxga="http://schemas.devexpress.com/winfx/2008/xaml/gauges"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>
        <!--State indicator represented by Ellipse-->
        <Ellipse x:Name="stateIndicator" Grid.Row="1"
                 Width="50" Height="50" 
                 Fill="Gray" />
        <!---->
        <dxga:CircularGaugeControl Grid.RowSpan="2"
                                   EnableAnimation= "True">
            <dxga:CircularGaugeControl.Scales>
                <dxga:ArcScale>
                    <dxga:ArcScale.Needles>
                        <dxga:ArcScaleNeedle IsInteractive="True" />
                    </dxga:ArcScale.Needles>
                    <dxga:ArcScale.Ranges>
                        <dxga:ArcScaleRange StartValue="10" EndValue="30"  
                                            IndicatorEnter="GreenRange_IndicatorEnter" 
                                            IndicatorLeave="GreenRange_IndicatorLeave"/>
                        <dxga:ArcScaleRange StartValue="30" EndValue="60"  
                                            IndicatorEnter="YellowRange_IndicatorEnter" 
                                            IndicatorLeave="YellowRange_IndicatorLeave" />
                        <dxga:ArcScaleRange StartValue="60" EndValue="90" 
                                            IndicatorEnter="RedRange_IndicatorEnter"   
                                            IndicatorLeave="RedRange_IndicatorLeave"/>
                    </dxga:ArcScale.Ranges>
                </dxga:ArcScale>
            </dxga:CircularGaugeControl.Scales>
        </dxga:CircularGaugeControl>
    </Grid>
</Window>

MainWindow.xaml.cs

using System.Windows;
using System.Windows.Media;
using DevExpress.Xpf.Gauges;

namespace DXGauges_RangeEvents {

    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
        }

        private void GreenRange_IndicatorEnter(object sender, IndicatorEnterEventArgs e) {
            stateIndicator.Fill = new SolidColorBrush(Colors.Green);
        }

        private void GreenRange_IndicatorLeave(object sender, IndicatorLeaveEventArgs e) {
            stateIndicator.Fill = new SolidColorBrush(Colors.Gray);
        }

        private void YellowRange_IndicatorEnter(object sender, IndicatorEnterEventArgs e) {
            stateIndicator.Fill = new SolidColorBrush(Colors.Yellow);
        }

        private void YellowRange_IndicatorLeave(object sender, IndicatorLeaveEventArgs e) {
            if (((e.NewValue) < 10) || (((e.NewValue) > 90)))
                stateIndicator.Fill = new SolidColorBrush(Colors.Gray);
        }

        private void RedRange_IndicatorEnter(object sender, IndicatorEnterEventArgs e) {
            stateIndicator.Fill = new SolidColorBrush(Colors.Red);
        }

        private void RedRange_IndicatorLeave(object sender, IndicatorLeaveEventArgs e) {
            if (((e.NewValue) < 10) || (((e.NewValue) > 90)))
                stateIndicator.Fill = new SolidColorBrush(Colors.Gray);
        }
    }
}

Inheritance

Object

EventArgs

ValueChangedEventArgs

IndicatorEnterLeaveEventArgs

IndicatorLeaveEventArgs