我试图在单击活动布局中的按钮时显示 GPS 坐标。以下是当我单击按钮时调用的方法:
public void getLocation(View view) {
TextView tv = (TextView) findViewById(R.id.gps_coord_view);
LocationManager lm = (LocationManager) getSystemService(LOCATION_SERVICE);
Location loc = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
tv.setText("Latitude: " + loc.getLatitude() + "\nLongitude: " + loc.getLongitude());
}
我收到一条错误消息
呼叫需要许可,可能会被用户拒绝。代码应明确检查权限是否可用。
我已经在我的
AndroidManifest
中授予了这些权限。当我在调用 lm.getLastKnownLocation
: 之前添加以下内容时,该错误已得到解决并且应用程序可以编译
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
&& checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
但是,当我按下单击时调用 getLocation 的按钮时,应用程序崩溃了。到底是怎么回事?有没有更好/更简单的方法来获取设备的 GPS 坐标?
对于 Android API 级别 (23),我们需要检查权限。 https://developer.android.com/training/permissions/requesting.html
我遇到了同样的问题,但以下方法对我有用,并且我能够成功检索位置数据:
(1) 确保您拥有清单中列出的权限:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
(2) 确保您向用户请求权限:
if ( ContextCompat.checkSelfPermission( this, android.Manifest.permission.ACCESS_COARSE_LOCATION ) != PackageManager.PERMISSION_GRANTED ) {
ActivityCompat.requestPermissions( this, new String[] { android.Manifest.permission.ACCESS_COARSE_LOCATION },
LocationService.MY_PERMISSION_ACCESS_COURSE_LOCATION );
}
(3) 确保使用 ContextCompat,因为它与旧版 API 级别兼容。
(4) 在您的位置服务或初始化 LocationManager 并获取最后已知位置的类中,我们需要检查权限:
if ( Build.VERSION.SDK_INT >= 23 &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return ;
}
(5) 这种方法仅在我在 initLocationService 方法顶部包含 @TargetApi(23) 后才对我有效。
(6) 我还将其添加到我的 gradle 构建中:
compile 'com.android.support:support-v4:23.0.1'
这是我的LocationService供参考:
public class LocationService implements LocationListener {
//The minimum distance to change updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 0; // 10 meters
//The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 0;//1000 * 60 * 1; // 1 minute
private final static boolean forceNetwork = false;
private static LocationService instance = null;
private LocationManager locationManager;
public Location location;
public double longitude;
public double latitude;
/**
* Singleton implementation
* @return
*/
public static LocationService getLocationManager(Context context) {
if (instance == null) {
instance = new LocationService(context);
}
return instance;
}
/**
* Local constructor
*/
private LocationService( Context context ) {
initLocationService(context);
LogService.log("LocationService created");
}
/**
* Sets up location service after permissions is granted
*/
@TargetApi(23)
private void initLocationService(Context context) {
if ( Build.VERSION.SDK_INT >= 23 &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED &&
ContextCompat.checkSelfPermission( context, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return ;
}
try {
this.longitude = 0.0;
this.latitude = 0.0;
this.locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
// Get GPS and network status
this.isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
this.isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (forceNetwork) isGPSEnabled = false;
if (!isNetworkEnabled && !isGPSEnabled) {
// cannot get location
this.locationServiceAvailable = false;
}
//else
{
this.locationServiceAvailable = true;
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
updateCoordinates();
}
}//end if
if (isGPSEnabled) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
updateCoordinates();
}
}
}
} catch (Exception ex) {
LogService.log( "Error creating location service: " + ex.getMessage() );
}
}
@Override
public void onLocationChanged(Location location) {
// do stuff here with location object
}
}
到目前为止,我仅使用 Android Lollipop 设备进行了测试。 希望这对你有用。
我想支持 api 23 之前的应用程序,而不是使用
checkSelfPermission
我使用了 try / catch 块
try {
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
} catch (SecurityException e) {
dialogGPS(this.getContext()); // lets the user know there is a problem with the gps
}
您引用的错误消息的最后一部分指出:
...with ("checkPermission") or explicitly handle a potential "SecurityException"
检查您是否拥有权限的一种更快/更简单的方法是用
try { ... } catch (SecurityException e) { [insert error handling code here] }
包围您的代码。如果您有权限,则“try”部分将执行,如果您没有权限,则“catch”部分将执行。
使用我的客户类别来检查或请求许可
public class Permissons {
//Request Permisson
public static void Request_STORAGE(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE},code);
}
public static void Request_CAMERA(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.CAMERA},code);
}
public static void Request_FINE_LOCATION(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.ACCESS_FINE_LOCATION},code);
}
public static void Request_READ_SMS(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.READ_SMS},code);
}
public static void Request_READ_CONTACTS(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.READ_CONTACTS},code);
}
public static void Request_READ_CALENDAR(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.READ_CALENDAR},code);
}
public static void Request_RECORD_AUDIO(Activity act,int code)
{
ActivityCompat.requestPermissions(act, new
String[]{Manifest.permission.RECORD_AUDIO},code);
}
//Check Permisson
public static boolean Check_STORAGE(Activity act)
{
int result = ContextCompat.checkSelfPermission(act,android.Manifest.permission.WRITE_EXTERNAL_STORAGE);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_CAMERA(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.CAMERA);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_FINE_LOCATION(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.ACCESS_FINE_LOCATION);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_READ_SMS(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.READ_SMS);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_READ_CONTACTS(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.READ_CONTACTS);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_READ_CALENDAR(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.READ_CALENDAR);
return result == PackageManager.PERMISSION_GRANTED;
}
public static boolean Check_RECORD_AUDIO(Activity act)
{
int result = ContextCompat.checkSelfPermission(act, Manifest.permission.RECORD_AUDIO);
return result == PackageManager.PERMISSION_GRANTED;
}
}
示例
if(!Permissons.Check_STORAGE(MainActivity.this))
{
//if not permisson granted so request permisson with request code
Permissons.Request_STORAGE(MainActivity.this,22);
}
如果您正在处理动态权限和任何权限(例如 ACCESS_FINE_LOCATION、ACCESS_COARSE_LOCATION),给出错误 “无法解析方法 PERMISSION_NAME” 在这种情况下,请使用权限名称编写代码,然后重建项目,这将重新生成清单(Manifest.permission)文件。
如果您只是想检查权限(而不是请求权限),我编写了一个简单的扩展,如下所示:
fun BaseActivity.checkPermission(permissionName: String): Boolean {
return if (Build.VERSION.SDK_INT >= 23) {
val granted =
ContextCompat.checkSelfPermission(this, permissionName)
granted == PackageManager.PERMISSION_GRANTED
} else {
val granted =
PermissionChecker.checkSelfPermission(this, permissionName)
granted == PermissionChecker.PERMISSION_GRANTED
}
}
现在,如果我想检查权限,我可以简单地传递一个权限,如下所示:
checkPermission(Manifest.permission.READ_CONTACTS)