xamarin 中的 Android 后台位置构建需要永远

Posted 2023-04-14

【中文标题】xamarin 中的 Android 后台位置构建需要永远

【英文标题】：Android background location build in xamarin is taking forever

【发布时间】：2017-09-20 17:57:47

【问题描述】：

所以我正在使用一个应用程序，它可以获取我当前的纬度、经度、当前速度等，使用 GPS 数据，该应用程序没有给我任何错误并成功部署，我正在使用我的手机（Sony Xperia D 2005 ) 来部署它。 无论如何，它说“等待位置更新”，但它需要永远...... 抱歉我要粘贴的所有代码行，但我不知道问题出在哪里。 这是我的 MainActivity.cs 代码：（我是 xamarin 的新手，我不知道这部分代码是否是造成问题的原因，所以如果您需要任何其他代码，请告诉我......）

using System;
using android.App;
using Android.Widget;
using Android.OS;
using Android.Util;
using Android.Locations;
using Location.Droid.Services;
using Android.Content.PM;

namespace Location.Droid

[Activity (Label = "LocationDroid", MainLauncher = true,
ConfigurationChanges = ConfigChanges.ScreenSize | 
ConfigChanges.Orientation | ConfigChanges.ScreenLayout)]
public class MainActivity : Activity

    readonly string logTag = "MainActivity";

    // make our labels
    TextView latText;
    TextView longText;
    TextView altText;
    TextView speedText;
    TextView bearText;
    TextView accText;

    #region Lifecycle

    //Lifecycle stages
    protected override void OnCreate (Bundle bundle)
    
        base.OnCreate (bundle);
        Log.Debug (logTag, "OnCreate: Location app is becoming active");

        SetContentView (Resource.Layout.Main);

        // This event fires when the ServiceConnection lets the client (our App class) know that
        // the Service is connected. We use this event to start updating the UI with location
        // updates from the Service
        App.Current.LocationServiceConnected += (object sender, ServiceConnectedEventArgs e) => 
            Log.Debug (logTag, "ServiceConnected Event Raised");
            // notifies us of location changes from the system
            App.Current.LocationService.LocationChanged += HandleLocationChanged;
            //notifies us of user changes to the location provider (ie the user disables or enables GPS)
            App.Current.LocationService.ProviderDisabled += HandleProviderDisabled;
            App.Current.LocationService.ProviderEnabled += HandleProviderEnabled;
            // notifies us of the changing status of a provider (ie GPS no longer available)
            App.Current.LocationService.StatusChanged += HandleStatusChanged;
        ;

        latText = FindViewById<TextView> (Resource.Id.lat);
        longText = FindViewById<TextView> (Resource.Id.longx);
        altText = FindViewById<TextView> (Resource.Id.alt);
        speedText = FindViewById<TextView> (Resource.Id.speed);
        bearText = FindViewById<TextView> (Resource.Id.bear);
        accText = FindViewById<TextView> (Resource.Id.acc);

        altText.Text = "altitude";
        speedText.Text = "speed";
        bearText.Text = "bearing";
        accText.Text = "accuracy";

        // Start the location service:
        App.StartLocationService();
    

    protected override void OnPause()
    
        Log.Debug (logTag, "OnPause: Location app is moving to background");
        base.OnPause();
    


    protected override void OnResume()
    
        Log.Debug (logTag, "OnResume: Location app is moving into foreground");
        base.OnResume();
    

    protected override void OnDestroy ()
    
        Log.Debug (logTag, "OnDestroy: Location app is becoming inactive");
        base.OnDestroy ();

        // Stop the location service:
        App.StopLocationService();
    

    #endregion

    #region Android Location Service methods

    ///<summary>
    /// Updates UI with location data
    /// </summary>
    public void HandleLocationChanged(object sender, LocationChangedEventArgs e)
    
        Android.Locations.Location location = e.Location;
        Log.Debug (logTag, "Foreground updating");

        // these events are on a background thread, need to update on the UI thread
        RunOnUiThread (() => 
            latText.Text = String.Format ("Latitude: 0", location.Latitude);
            longText.Text = String.Format ("Longitude: 0", location.Longitude);
            altText.Text = String.Format ("Altitude: 0", location.Altitude);
            speedText.Text = String.Format ("Speed: 0", location.Speed);
            accText.Text = String.Format ("Accuracy: 0", location.Accuracy);
            bearText.Text = String.Format ("Bearing: 0", location.Bearing);
        );

    

    public void HandleProviderDisabled(object sender, ProviderDisabledEventArgs e)
    
        Log.Debug (logTag, "Location provider disabled event raised");
    

    public void HandleProviderEnabled(object sender, ProviderEnabledEventArgs e)
    
        Log.Debug (logTag, "Location provider enabled event raised");
    

    public void HandleStatusChanged(object sender, StatusChangedEventArgs e)
    
        Log.Debug (logTag, "Location status changed, event raised");
    

    #endregion

【问题讨论】：

确保您获得适当的权限，请查看github.com/xamarin/mobile-samples/blob/master/…

【参考方案1】：

在这种情况下，您应该同时注册 GPS 和 NETWORK 提供商。

LocMgr.RequestLocationUpdates(LocationManager.GpsProvider, 2000, 0, this);
LocMgr.RequestLocationUpdates(LocationManager.NetworkProvider, 2000, 0, this);

GPS 提供商在外面工作，而 NETWORK 使用手机信号塔和 wifi。

这个article 可以帮助您如何优化您的代码。