Java 从Android获取gps位置
我不知道为什么,但我无法再使用几个月前构建的同一个应用程序获取gps位置 这就是简单的代码:Java 从Android获取gps位置,java,android,gps,location,Java,Android,Gps,Location,我不知道为什么,但我无法再使用几个月前构建的同一个应用程序获取gps位置 这就是简单的代码: public class MainActivity extends AppCompatActivity { private Button b; private TextView t; private LocationManager locationManager; private LocationListener listener;
public class MainActivity extends AppCompatActivity {
private Button b;
private TextView t;
private LocationManager locationManager;
private LocationListener listener;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
t = (TextView) findViewById(R.id.textView);
b = (Button) findViewById(R.id.button);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
listener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
t.setText(Double.toString(location.getLongitude()));
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(i);
}
};
configure_button();
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode){
case 10:
configure_button();
break;
default:
break;
}
}
void configure_button(){
// first check for permissions
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION,Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.INTERNET}
,10);
}
return;
}
// this code won't execute IF permissions are not allowed, because in the line above there is return statement.
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//noinspection MissingPermission
locationManager.requestLocationUpdates("gps", 5000, 0, listener);
}
});
}
}
以及在清单中添加的权限:
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
正如您所看到的,这是一个非常简单的代码。当我单击按钮时,gps图标出现,但不显示经度。为什么?你能帮助我吗?奇怪的是,正如我所说,几个月前,这段代码可以完美地工作 试试这个:
public class MainActivity extends AppCompatActivity {
private Button b;
private TextView t;
private LocationManager locationManager;
private LocationListener listener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
b = (Button) findViewById(R.id.button);
t = (TextView) findViewById(R.id.textView);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
listener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
t.setText(String.valueOf(location.getLongitude()));
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
//
}
@Override
public void onProviderEnabled(String s) {
//
}
@Override
public void onProviderDisabled(String s) {
Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(i);
}
};
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
configure_button();
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
@NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case 10:
configure_button();
break;
default:
break;
}
}
void configure_button() {
// first check for permissions
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(MainActivity.this,
ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
request_permission();
}
} else {
// permission has been granted
locationManager.requestLocationUpdates("gps", 5000, 0, listener);
}
}
private void request_permission() {
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
ACCESS_COARSE_LOCATION)) {
Snackbar.make(findViewById(R.id.main_linear_layout), "Location permission is needed because ...",
Snackbar.LENGTH_LONG)
.setAction("retry", new View.OnClickListener() {
@Override
public void onClick(View view) {
requestPermissions(new String[]{ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 10);
}
})
.show();
} else {
// permission has not been granted yet. Request it directly.
requestPermissions(new String[]{ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 10);
}
}
}
将configure_button()
提取到按钮的onClickListener。这样,您仅在需要权限时(单击按钮时)请求权限。当用户拒绝权限时,它也会有所帮助,因为以后单击按钮将再次请求权限
还有一条消息告诉用户为什么需要权限,以及一条请求权限的消息。使用调试器。是否添加了侦听器?此外,您的
配置按钮中的返回似乎是错误的。如果权限尚未授予,则它将有条件地请求这些权限。无论结果如何,它都将返回并不会连接侦听器。当您调用RequestLocationUpdate时,从gps传感器请求位置不会立即产生值。您应该等待,直到获得位置。