Question

我试图通过单击按钮来访问位置并在文本视图中显示纬度和经度。

这是我的代码：

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationManager;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

public class MainActivity extends Activity {

    TextView textView, textView1;
    Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = findViewById(R.id.textView);
        textView1 = findViewById(R.id.textView2);
        button = findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    boolean enableOnly = true;
                    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
                    List<String> providers = locationManager.getProviders(enableOnly);

                    for (String provider : providers) {
                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                            if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                                Location location = locationManager.getLastKnownLocation(provider);
                                if (location != null) {
                                    textView.setText((int) location.getLatitude());
                                    textView1.setText((int) location.getLatitude());
                                } else {
                                    Toast.makeText(MainActivity.this, "sorry", Toast.LENGTH_SHORT).show();
                                }
                                return;
                            }
                        }
                    }
            }

            });

    }
}

我正在测试的AVD在Android 8.1上我还在AndroidManifest中设置了用户权限，以访问粗略和精细的位置。位置权限也已授予该应用。

但是，每当我单击按钮时，都不会发生任何事情。请帮帮我。

Answer 1

if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) == 
PackageManager.PERMISSION_GRANTED && 
checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) == 
PackageManager.PERMISSION_GRANTED) {
    //do your task
}

此代码也仅适用于您提到的上述棉花糖设备

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

}

Answer 2

使用此代码：

LocationManager mLocationManager;
Location myLocation = getLastKnownLocation();

private Location getLastKnownLocation() {
    mLocationManager = (LocationManager)getApplicationContext().getSystemService(LOCATION_SERVICE);
    List<String> providers = mLocationManager.getProviders(true);
    Location bestLocation = null;
    for (String provider : providers) {
        Location l = mLocationManager.getLastKnownLocation(provider);
        if (l == null) {
            continue;
        }
        if (bestLocation == null || l.getAccuracy() < bestLocation.getAccuracy()) {
            // Found best last known location: %s", l);
            bestLocation = l;
        }
    }
    return bestLocation;
}

Answer 3

抱歉，我没有看到您的许可。现在，只要授予权限，就使用setUpGPS：

Application.Current.Dispatcher.BeginInvoke(new System.Action(() => {
        /* code you want to run on the GUI thread goes here */
})).Wait();

onLocationChanged方法具有两个方法：getLatitude和getLongitude。这些是用户的位置点。您可以在double变量中传递它们并使用它们。

无法访问位置

3 个答案: