Xamarin 后台持续定位与提示

IOS后台持续运行对于c#程序员不懂得ios后台机制的是存在一定困扰的。特别是ios9过后对后台和安全进行了更严格的限制

好了废话不多说

一 设置info.plist权限信息

参考：

后台模式：http://www.codeceo.com/article/ios-background-guide.html

后台持续定位：http://www.jianshu.com/p/4e30b0af8f51

播放声音：http://www.jianshu.com/p/e54751348abe

需要开启后台运行模式：勾选位置更新，音频播放

二 关键代码

2.1 设置

 coo.DistanceFilter = -;//设置两点之间位置精度，即手机不动也会提示
 coo.DesiredAccuracy = CLLocation.AccuracyBest;
 coo.AllowsBackgroundLocationUpdates = true;//开启后台持续定位
 coo.PausesLocationUpdatesAutomatically = false;//禁用后台暂停位置更新
 coo.Delegate = this;
 coo.RequestAlwaysAuthorization();

 coo.StartUpdatingLocation();
 coo.StartUpdatingHeading();

2.2 前后台切换

        public override void DidEnterBackground(UIApplication uiApplication)
        {
　　　　　　　//进入后台
            DependencyService.Get<ILocationManager>().EnterBackground();
        }

        public override void WillEnterForeground(UIApplication uiApplication)
        {
　　　　　　　//进入前台
            DependencyService.Get<ILocationManager>().EnterForground();
        }

三 播放音频(系统提示音)

var sound = new SystemSound();

await sound.PlaySystemSoundAsync();

四 实现结果

当位置发生更新时播放系统提示音，且伴有震动，这里暂时对ios消息推送不甚了解，下次将在位置更新播放提示音同时加入本地推送

这里是使用xamarin.ios 原生api实现，之前试过百度地图持续最新sdk弄了半天进入后台就不行了，也许是我知识不够，但是使用原生api也行那么也就不用那么麻烦了

五 完整代码

[assembly: Dependency(typeof(MyLocationManager))]

namespace Xamarin.Simples.iOS
{
    public class MyLocationManager : NSObject, ICLLocationManagerDelegate, ILocationManager
    {
        private CLLocationManager coo;
        private bool init = false;
        public MyLocationManager()
        {
            coo = new CLLocationManager();

        }

        #region ICLLocationManagerDelegate

        #region IDisposable implementation

        void IDisposable.Dispose()
        {
            throw new NotImplementedException();
        }

        #endregion

        #region INativeObject implementation

        IntPtr ObjCRuntime.INativeObject.Handle
        {
            get
            {
                throw new NotImplementedException();
            }
        }

        #endregion

        [Foundation.Export("locationManager:didUpdateLocations:")]
        public async void LocationsUpdated(CoreLocation.CLLocationManager manager, CoreLocation.CLLocation[] locations)
        {
            Console.WriteLine("定位成功");

            var sound = new SystemSound();

            await sound.PlaySystemSoundAsync();

        }

        [Export("locationManager:didUpdateHeading:")]
        public void UpdatedHeading(CoreLocation.CLLocationManager manager, CoreLocation.CLHeading newHeading)
        {

        }

        [Foundation.Export("locationManager:didUpdateToLocation:fromLocation:")]
        public void UpdatedLocation(CoreLocation.CLLocationManager manager, CoreLocation.CLLocation newLocation, CoreLocation.CLLocation oldLocation)
        {

        }

        #endregion

        public void Init()
        {
            if (!init)
            {
                coo.DistanceFilter = -;
                coo.DesiredAccuracy = CLLocation.AccuracyBest;
                coo.AllowsBackgroundLocationUpdates = true;
                coo.PausesLocationUpdatesAutomatically = false;
                coo.Delegate = this;
                coo.RequestAlwaysAuthorization();

                coo.StartUpdatingLocation();
                coo.StartUpdatingHeading();

                init = true;
            }

        }

        public void EnterBackground()
        {
            if (init)
                coo.StartMonitoringSignificantLocationChanges();
        }

        public void EnterForground()
        {
            if (init)
                coo.StopMonitoringSignificantLocationChanges();
        }

    }
}

六  案例下载

https://yunpan.cn/cqegpGW96nYx7 （提取码：4508）