C# 使用xamarin Android&C从SQLite检索数据？

我有一个类，它从用户的设备获取经度和纬度，并将其保存到SQLite数据库。代码如下：

    [Activity(Label = "GetLocation")]
public class GetLocation : Activity, ILocationListener
{
    Button btncreate;
    EditText txtlong;
    EditText txtlat;

    static readonly string TAG = "X:" + typeof(GetLocation).Name;
    Location _currentLocation;
    LocationManager _locationManager;
    string _locationProvider;

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.GetLocation);
        txtlong = FindViewById<EditText>(Resource.Id.txtlong);
        txtlat = FindViewById<EditText>(Resource.Id.txtlat);
        btncreate = FindViewById<Button>(Resource.Id.btnvalidate);
        btncreate.Click += Btncreate_Click;

        InitializeLocationManager();
    }

    void InitializeLocationManager()
    {
        _locationManager = (LocationManager) GetSystemService(LocationService);
        Criteria criteriaForLocationService = new Criteria
                                              {
                                                  Accuracy = Accuracy.Fine
                                              };
        IList<string> acceptableLocationProviders = _locationManager.GetProviders(criteriaForLocationService, true);
        if (acceptableLocationProviders.Any())
        {
            _locationProvider = acceptableLocationProviders.First();
        }
        else
        {
            _locationProvider = string.Empty;
        }
        Log.Debug(TAG, "Using " + _locationProvider + ".");
    }

    public void OnProviderDisabled(string provider) { }
    public void OnProviderEnabled(string provider) { }
    public void OnStatusChanged(string provider, Availability status, Bundle extras) { }

    protected override void OnResume()
    {
        base.OnResume();
        _locationManager.RequestLocationUpdates(_locationProvider, 0, 0, this);
    }

    protected override void OnPause()
    {
        base.OnPause();
        _locationManager.RemoveUpdates(this);
    }

    public void OnLocationChanged(Location location)
    {
        _currentLocation = location;
        if (_currentLocation == null)
        {
            txtlong.Text = "Unable to determine your location. Try again in a short while.";
            txtlat.Text = "Unable to determine your location. Try again in a short while.";
        }
        else
        {
            txtlong.Text = _currentLocation.Longitude.ToString();
            txtlat.Text = _currentLocation.Latitude.ToString();
        }
    }

    private void Btncreate_Click(object sender, EventArgs e)
    {
        try
        {
            string dpPath = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "Location.db3");
            var db = new SQLiteConnection(dpPath);
            db.CreateTable<DataTable>();
            DataTable tbl = new DataTable();
            tbl.Longitude = txtlong.Text;
            tbl.Latitude = txtlat.Text;
            db.Insert(tbl);
            NextPage();
            Toast.MakeText(this, "Data Store Successfully...,", ToastLength.Short).Show();
        }
        catch (Exception ex)
        {
            Toast.MakeText(this, ex.ToString(), ToastLength.Short).Show();
        }
    }
    void NextPage()
    {
        //code to get next page
    }

}

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一旦它保存了数据，我希望另一个类活动能够在单独的.axml页面上显示它。我的问题是我是一名培训学院的程序员，不知道该做什么。非常感谢您的帮助。

您需要使用

StartActivity(typeof(Activity2));

在Activity2的OnCreate中，设置新的.axml布局：

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    SetContentView(Resource.Layout.MyView);
}

然后使用查询检索数据：

我建议您阅读，如果您想改进，请将所有关于SQLite的内容移动到另一个类，以重用打开SQLite连接的代码。另外，如果您可以使用异步调用，以防止在数据库中持久化数据时阻塞UI

还要检查这是否真的有用

---

HIH

请出示您的数据表。编辑你的问题并把它放进去。我很困惑？您好，我需要为.axml文件添加一些特定的内容吗？当然，因为当活动加载时，我会得到一个空白页。您需要在axml中对活动进行布局。如果它很简单，你可以在设计师的帮助下显示它。

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    SetContentView(Resource.Layout.MyView);
}

string dpPath = Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal), "Location.db3");
var db = new SQLiteConnection(dpPath);
var dataTables = db.Query<DataTable>("select * from DataTable");