GeoCoordinateWatcher.PositionChanged 事件

定义

命名空间:

System.Device.Location

程序集:

System.Device.dll

指示位置数据的纬度或经度已更改。

public:
 event EventHandler<System::Device::Location::GeoPositionChangedEventArgs<System::Device::Location::GeoCoordinate ^> ^> ^ PositionChanged;

public event EventHandler<System.Device.Location.GeoPositionChangedEventArgs<System.Device.Location.GeoCoordinate>> PositionChanged;

member this.PositionChanged : EventHandler<System.Device.Location.GeoPositionChangedEventArgs<System.Device.Location.GeoCoordinate>> 

Public Event PositionChanged As EventHandler(Of GeoPositionChangedEventArgs(Of GeoCoordinate)) 

事件类型

EventHandler<GeoPositionChangedEventArgs<GeoCoordinate>>

实现

PositionChanged

示例

以下示例演示如何处理第一个 PositionChanged 事件。

using System;
using System.Device.Location;

namespace LocationEvent1
{
    class Program
    {
        static void Main(string[] args)
        {
            GeoCoordinateWatcher watcher;
            watcher = new GeoCoordinateWatcher();

            watcher.PositionChanged += (sender, e) =>
            {
                var coordinate = e.Position.Location;
                Console.WriteLine("Lat: {0}, Long: {1}", coordinate.Latitude,
                    coordinate.Longitude);
                // Uncomment to get only one event.
                // watcher.Stop();
            };

            // Begin listening for location updates.
            watcher.Start();
        }
    }
}

Imports System.Device.Location

Module GetLocationEvent
    Public Class CLocation
        Private WithEvents watcher As GeoCoordinateWatcher
        Public Sub GetLocationDataEvent()
            watcher = New System.Device.Location.GeoCoordinateWatcher()
            AddHandler watcher.PositionChanged, AddressOf watcher_PositionChanged
            watcher.Start()

        End Sub

        Private Sub watcher_PositionChanged(ByVal sender As Object, ByVal e As GeoPositionChangedEventArgs(Of GeoCoordinate))
            PrintPosition(e.Position.Location.Latitude, e.Position.Location.Longitude)
            ' Uncomment the following to stop receiving updates after the first one.
            ' watcher.Stop()
        End Sub

        Private Sub PrintPosition(ByVal Latitude As Double, ByVal Longitude As Double)
            Console.WriteLine("Latitude: {0}, Longitude {1}", Latitude, Longitude)
        End Sub
    End Class


    Public Sub Main()
        Dim myLocation As New CLocation()
        myLocation.GetLocationDataEvent()
        Console.WriteLine("Enter any key to quit.")
        Console.ReadLine()
    End Sub

End Module

注解

仅当自上次事件以来移动的距离超过 指定的 MovementThreshold阈值时，才会引发此事件。

GeoPositionChangedEventArgs<T>传递给事件处理程序的对象包含GeoPosition<T>包含更新的位置数据的对象。

另请参阅

• MovementThreshold