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SDK not registering (from non view constructor, not an onCreate()) - No errors

I am making a cleaner version of a research drone android app that utilises DJI SDK/Hardware and attempting to structure the app more appropriately such that it can be expanded later. The application allows user selection of hardware (currently mock/test, DJI and ToDo) from a config pop up in the main display (class UserInterface extends AppCompatActivity). This is to allow the app to be used without registering or check perms when it is not being used for DJI. Previously I registered the DJI SDK when the app first opens, but it was my first real app and was a mess to follow its flow and didn't manage screen real estate very well.
When the DJI option is actioned from the pop up "config" window on the main interface from UI class, the UI class saves the config to a SettingsManager instance and calls the EventsManager instance with method runSettings(). The method actions the relevant SDK by try/catch{new DJI SDK class} and passes both the instances of EventsManager and UI.
The difference of this major version compared to my first version (which functions correctly) is the API key (changed package name, so new key), I am not doing the SDK registration in the first main activity and the SDK registration is not a viewable class, it only forwards strings to run on UI thread for showToast method in the UI class.
App does not return any errors.
showToast for messages in the DJI SDK class appear on the display but nothing inside the
SDKManagerCallback occurs.
Unsure of constructor in a class with extends AppCompatActivity, context methods seem unavailable when
tried with different class extensions.
I have tried creating two DJI developer keys, no difference.
Unsure of DJI class listing in Manifest as it is not an activity started by an intent with bundle but
does require context.
DJI SDK class is extracted from DJISDKDemo (I am fairly new to android app development, not sure I
could write my own version from the limited explanation on DJI dev site).
Thank you greatly for your help and any other tips appreciated.
The SDKRegistration class:
package com.research.droneapp; // mock package name for SO
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Handler;
import android.os.Looper;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import dji.common.error.DJIError;
import dji.common.error.DJISDKError;
import dji.sdk.base.BaseComponent;
import dji.sdk.base.BaseProduct;
import dji.sdk.sdkmanager.DJISDKInitEvent;
import dji.sdk.sdkmanager.DJISDKManager;
public class SoftwareDevelopmentKitDJI extends AppCompatActivity {
private static final String TAG = "SoftwareDevelopmentKit";
public UserInterface userInterface;
public EventsManager eventsManager;
public static final String FLAG_CONNECTION_CHANGE = "dji_sdk_connection_change";
private static BaseProduct mProduct;
private Handler mHandler;
public boolean isConnected = false; // Variable for start up flag
private static final String[] REQUIRED_PERMISSION_LIST = new String[]{
Manifest.permission.VIBRATE,
Manifest.permission.INTERNET,
Manifest.permission.ACCESS_WIFI_STATE,
Manifest.permission.WAKE_LOCK,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_NETWORK_STATE,
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.CHANGE_WIFI_STATE,
Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.BLUETOOTH,
Manifest.permission.BLUETOOTH_ADMIN,
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.READ_PHONE_STATE,
};
private List<String> missingPermission = new ArrayList<>();
private AtomicBoolean isRegistrationInProgress = new AtomicBoolean(false);
private static final int REQUEST_PERMISSION_CODE = 12345;
public SoftwareDevelopmentKitDJI(UserInterface userInterface, EventsManager eventsManager) {
Log.d(TAG, "SoftwareDevelopmentKitDJI");
this.userInterface = userInterface;
this.eventsManager = eventsManager;
// Permission checked true actions SDK registration
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkAndRequestPermissions();
}
// Handle DJI SDK hardware changes in background thread??
// ToDo: Receive hardware changes in EventsManager
mHandler = new Handler(Looper.getMainLooper());
}
/**
* Checks if there is any missing permissions, and
* requests runtime permission if needed.
*/
private void checkAndRequestPermissions() {
Log.d(TAG, "checkAndRequestPermissions: S");
// Check for permissions
for (String eachPermission : REQUIRED_PERMISSION_LIST) {
if (ContextCompat.checkSelfPermission(userInterface, eachPermission) !=
PackageManager.PERMISSION_GRANTED) {
missingPermission.add(eachPermission);
}
}
// Request for missing permissions
if (missingPermission.isEmpty()) {
Log.d(TAG, "notMissingPerms");
startSDKRegistration();
} else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
Log.d(TAG, "missingPerms");
passToastToUI("Need permissions!");
ActivityCompat.requestPermissions(userInterface,
missingPermission.toArray(new String[missingPermission.size()]),
REQUEST_PERMISSION_CODE);
}
Log.d(TAG, "checkAndRequestPermissions: E");
}
/**
* Result of runtime permission request
*/
#Override
public void onRequestPermissionsResult(int requestCode,
#NonNull String[] permissions,
#NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
// Check for granted permission and remove from missing list
if (requestCode == REQUEST_PERMISSION_CODE) {
for (int i = grantResults.length - 1; i >= 0; i--) {
if (grantResults[i] == PackageManager.PERMISSION_GRANTED) {
missingPermission.remove(permissions[i]);
}
}
}
// If no missing permission, start SDK registration
if (missingPermission.isEmpty()) {
startSDKRegistration();
} else {
passToastToUI("Missing permissions!!!");
}
}
private void startSDKRegistration() {
Log.d(TAG, "startSDKRegistration: S");
if (isRegistrationInProgress.compareAndSet(false, true)) {
AsyncTask.execute(new Runnable() {
#Override
public void run() {
passToastToUI("registering, pls wait...");
Log.d(TAG, "startSDKRegistration: run");
// ToDO: Investigate why SDKManagerCallback's don't occur
// (is getApplicationContext() correct?)
DJISDKManager.getInstance().registerApp(getApplicationContext(),
new DJISDKManager.SDKManagerCallback() {
#Override
public void onRegister(DJIError djiError) {
Log.d(TAG, "onRegister: S");
if (djiError == DJISDKError.REGISTRATION_SUCCESS) {
passToastToUI("Register Success");
DJISDKManager.getInstance().startConnectionToProduct();
}
else {
passToastToUI("Register sdk failed!");
}
Log.v(TAG, djiError.getDescription());
Log.d(TAG, "onRegister: E");
}
#Override
public void onProductDisconnect() {
Log.d(TAG, "onProductDisconnect");
passToastToUI("Product Disconnected");
notifyStatusChange();
isConnected = false; // Set hardware connection flag
}
#Override
public void onProductConnect(BaseProduct baseProduct) {
Log.d(TAG, String.format("onProductConnect newProduct:%s", baseProduct));
passToastToUI("Product Connected");
notifyStatusChange();
isConnected = true; // Set hardware connection flag
}
#Override
public void onComponentChange(BaseProduct.ComponentKey componentKey, BaseComponent oldComponent,
BaseComponent newComponent) {
if (newComponent != null) {
newComponent.setComponentListener(new BaseComponent.ComponentListener() {
#Override
public void onConnectivityChange(boolean isConnected) {
Log.d(TAG, "onComponentConnectivityChanged: " + isConnected);
notifyStatusChange();
}
});
}
Log.d(TAG, String.format(
"onComponentChange key:%s, oldComponent:%s, newComponent:%s",
componentKey, oldComponent, newComponent));
}
#Override
public void onInitProcess(DJISDKInitEvent djisdkInitEvent, int i) {
Log.d(TAG, "startSDKRegistration: onInitProcess");
}
#Override
public void onDatabaseDownloadProgress(long l, long l1) {
Log.d(TAG, "startSDKRegistration: onDatabaseDownloadProgress");
}
});
}
});
}
Log.d(TAG, "startSDKRegistration: E");
}
private void notifyStatusChange() {
mHandler.removeCallbacks(updateRunnable);
mHandler.postDelayed(updateRunnable, 500);
}
private Runnable updateRunnable = () -> {
Intent intent = new Intent(FLAG_CONNECTION_CHANGE);
sendBroadcast(intent);
};
private void passToastToUI(String toastMsg) {
runOnUiThread(() -> {
userInterface.showToast(toastMsg);
});
}
}
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.research.droneapp"> <!-- mock package name for SO -->
<!-- Permissions and features -->
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"
tools:ignore="ProtectedPermissions" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-feature
android:name="android.hardware.usb.host"
android:required="false" />
<uses-feature
android:name="android.hardware.usb.accessory"
android:required="true" />
<!-- App Activity Process -->
<application
android:name="com.research.droneapp.MApplication"
android:allowBackup="true"
android:icon="#mipmap/hmu_icon"
android:label="#string/app_name"
android:roundIcon="#mipmap/hmu_icon_round"
android:supportsRtl="true"
android:theme="#style/Theme.AppCompat.NoActionBar">
<!-- Main Display -->
<activity android:name="com.research.droneapp.UserInterface" />
<!-- DJI SDK -->
<uses-library android:name="com.android.future.usb.accessory" />
<meta-data
android:name="com.dji.sdk.API_KEY"
android:value="*************" /> <!-- removed for SO -->
<activity
android:name="dji.sdk.sdkmanager.DJIAoaControllerActivity"
android:theme="#android:style/Theme.Translucent">
<intent-filter>
<action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" />
</intent-filter>
<meta-data
android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED"
android:resource="#xml/accessory_filter" />
</activity>
<service android:name="dji.sdk.sdkmanager.DJIGlobalService">
</service>
<activity android:name="com.research.droneapp.SoftwareDevelopmentKitDJI" />
<!-- Splash Screen at Launch -->
<activity android:name="com.research.droneapp.Splash" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
The method that starts the SDK class:
/**
* Settings changes to start relevant classes
*/
public void runSettings() {
Log.d(TAG, "runSettings: S");
// Get hardware selection from settings
int hardwarePosition = settingsManager.getHardwareInt();
/*ToDo: Set Test Environment*/
if (hardwarePosition == 0) { // Operate settings for test environment
Log.d(TAG, "runSettings: hardPos Test");
userInterface.showToast("runSetting: TEST");
}
else if (hardwarePosition == 1) { // Operate settings for DJI
Log.d(TAG, "runSettings: hardPos MavP2");
try {
this.softwareDevelopmentKitDJI = new SoftwareDevelopmentKitDJI(
userInterface, this);
Log.d(TAG, "runSettings: DJI Launched");
userInterface.showToast("runSetting: DJI");
} catch (Exception e) {
Log.d(TAG, "runSettings: DJI Error: "+ e.toString());
userInterface.showToast("runSetting: Error");
}
} // Operate settings for...?
else if (hardwarePosition == 2) { /*ToDo*/
Log.d(TAG, "runSettings: hardPos ToDo");
userInterface.showToast("runSetting: ToDo");
}
else { // Unknown hardware
Log.d(TAG, "runSettings: Error");
userInterface.showToast("runSetting:Error");
}
Log.d(TAG, "runSettings: E");
}
The config window click listener for action changes button, within the method of UI class for config pop up window:
// Action changes
Button btnAction = popupView.findViewById(R.id.btnAction);
btnAction.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Log.d(TAG, "displayConfigOverlay: onClick -> configAction");
// Update hardware setting
String hardware =
(btnTest.isChecked())?settingsManager.HARDWARE_OPTIONS[0]:
(btnMavP2.isChecked())?settingsManager.HARDWARE_OPTIONS[1]:
(btnToDo.isChecked())?settingsManager.HARDWARE_OPTIONS[2]:
"NoSelection!";
settingsManager.setHardware(hardware);
// Update port number
String port = serverPortEdit.getText().toString();
settingsManager.setServerPort(port);
// Update WSS launch setting
boolean autoLunchWSS = swAutoWSS.isChecked();
settingsManager.setAutoLaunchWSS(autoLunchWSS);
// Display to user
showToast("Hardware: " + hardware + "\nPort: " + port + "\nAutoWSS: " +
autoLunchWSS);
// Push settings
eventsManager.runSettings();
// Close config pop up
popupConfig.dismiss();
}
});
Apologises for the lack of and mixed commenting styles. Again any tips appreciated, still new to android and java.

Min API23 setting in gradle allowed code to run but did not allow SDK to download. Unsure why errors not returned.
Solved by changing gradle to following:
...
android {
compileSdkVersion 29
buildToolsVersion '28.0.3'
useLibrary 'org.apache.http.legacy'
defaultConfig {
minSdkVersion 19
targetSdkVersion 29
multiDexEnabled true
ndk {
abiFilters 'armeabi-v7a', 'x86', 'arm64-v8a'
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
debug {
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
...
Additionally found a potential context issue within layout, tools:context="..." was not set to the Activity interacting with this layout.
...
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/mainConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".UserInterface" >
...

Phone not making calls with Intent Android_Call

I'm having some trouble with Intent Action_Call. I put the permission in Manifest, but it doesn't work. I press the button to Call and nothing happens. The app that I'm making is an app that does multiple Intents so the code isn't in MainActivity. I don't know if it helps, but I'm using API 28.
Thanks for reading.
MANIFEST:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.intentsimplicitas">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CALL_PHONE"/>
<uses-permission android:name="android.permission.READ_SMS" />
<uses-permission android:name="android.permission.WRITE_SMS" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".SmsActivity"></activity>
<activity android:name=".DialActivity" />
<activity android:name=".WaysActivity" />
<activity android:name=".MapActivity" />
<activity android:name=".PageActivity" />
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
JAVA (DialActivity.java)
public class DialActivity extends Activity {
Button btnDial;
EditText edtPhone;
String phone;
Intent it;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dial);
btnDial = (Button)findViewById(R.id.btnDial);
edtPhone = (EditText)findViewById(R.id.edtPhone);
}
public void dialClick (View v) {
phone = edtPhone.getText().toString();
Uri uri = Uri.parse("tel: " + phone);
it = new Intent(Intent.ACTION_CALL);
it.setData(uri);
startActivity(it);
}
}

From https://developer.android.com/training/permissions/requesting:
Requesting permission:
// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
Manifest.permission.CALL_PHONE)
!= PackageManager.PERMISSION_GRANTED) {
// Permission is not granted
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
Manifest.permission.CALL_PHONE)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed; request the permission
ActivityCompat.requestPermissions(thisActivity,
new String[]{Manifest.permission.CALL_PHONE},
MY_PERMISSIONS_REQUEST_CALL_PHONE);
// MY_PERMISSIONS_REQUEST_CALL_PHONE is an
// app-defined int constant. The callback method gets the
// result of the request.
}
} else {
// Permission has already been granted
}
Verifying:
#Override
public void onRequestPermissionsResult(int requestCode,
String[] permissions, int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_CALL_PHONE: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, yay! Do the
// contacts-related task you need to do.
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
// other 'case' lines to check for other
// permissions this app might request.
}
}

You can do via Intent
public void dialClick (View v) {
phone = edtPhone.getText().toString();
Uri uri = Uri.parse("tel: " + phone);
it = new Intent(Intent.ACTION_DIAL);
it.setData(uri);
startActivity(it);
}

You need to add the permissions at run time to be able to make the call, I recommend the following library, since it is much easier to implement the permissions in time of execution.
https://github.com/Karumi/Dexter

Requesting Runtime Permissions Causes Crash

The main reason I'm posting here is that I'm currently stuck without a computer that can run an emulator, I've been having to send the APK to my phone to test it. Even if my phone's connected to my computer, or I have a third party emulator running, it wont work. Due to this...I have no error logs.
The app is a simple password manager, and all the other functions thus far work. I was trying to add an export function, I can't get either to actually write anything. I've checked other questions and various sources online, but I cannot seem to figure out what could be causing it. When the method is called, it simply doesn't do anything as far as I can tell. I apologize if I'm missing something, or if there was indeed another question with the same issue. I couldn't find anything missing.
Here is the method I'm using;
EDIT: The code has been updated to reflect a better method of requesting runtime permissions, which was suggested here. This ultimately is what fixed the application.
//Method017: Exports the account info to a .txt file.
public void exportData() throws IOException {
//Opens dialog to request permission.
ActivityCompat.requestPermissions(Main.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}
//Method to handle result of permission request.
#Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case 1: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//Attempt to write a file to the Download folder.
String content = "hello world";
File file;
FileOutputStream outputStream;
try {
file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "MyCache");
outputStream = new FileOutputStream(file);
outputStream.write(content.getBytes());
outputStream.close();
//According to an online source, this is necessary to make the file viewable on the device.
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(file));
sendBroadcast(intent);
} catch (IOException e) {
e.printStackTrace();
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(Main.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
And my manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.brand.psync">
<application
android:allowBackup="true"
android:icon="#drawable/psynclogo"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme"
android:screenOrientation="portrait">
<activity android:name=".Main">
<intent-filter>
<action
android:name="android.intent.action.MAIN"
android:screenOrientation="portrait" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<category
android:name="android.intent.category.LAUNCHER"
android:screenOrientation="portrait" />
</intent-filter>
</activity>
</application>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</manifest>
Sorry about the lack of error log...but if I had that, I likely wouldn't need to post here.

I have try your code and it working.
public class SaveFileSampleActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TextView lblBackground = new TextView(this);
lblBackground.setBackgroundColor(Color.WHITE);
setContentView(lblBackground);
ActivityCompat.requestPermissions(SaveFileSampleActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
}
#Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case 1: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//Attempt to write a file to the Download folder.
String content = "hello world";
File file;
FileOutputStream outputStream;
try {
file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "MyCache");
outputStream = new FileOutputStream(file);
outputStream.write(content.getBytes());
outputStream.close();
//According to an online source, this is necessary to make the file viewable on the device.
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(Uri.fromFile(file));
sendBroadcast(intent);
} catch (IOException e) {
e.printStackTrace();
}
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
Toast.makeText(SaveFileSampleActivity.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show();
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
}
And mainifest
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".SaveFileSampleActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
It's work and result:
You can review your code. I hope it can help you!

Android App doesn't show location

I was looking for the solution to my problem the whole day now, but I couldn't find out. I'm absolutely new to java/android studio/app programming and probably it's just a very small thing that I don't see.
I just want my App to show the current location of the device. Nothing more.
When running the App on the emulator, no error is shown and the App starts.
Then I open the extended controls and push the "SEND"-button in "Location".
Now I would expect my App to show the current location, but nothing happens. The TextViews "textLat", "textLong" and "textAlt" are staying empty.
I have absolutely no Idea what my fault is. I wrote that code with the help of different tutorials. I also tried it on my real device.
I would be very grateful for any help! Thanks alot!
package com.example.findlocation_test2;
import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.provider.Settings;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
TextView textLat;
TextView textLong;
TextView textAlt;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textLat = (TextView) findViewById(R.id.textLat);
textLong = (TextView) findViewById(R.id.textLong);
textAlt = (TextView) findViewById(R.id.textAlt);
LocationManager lm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
LocationListener ll = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
if(location != null) {
double dLat = location.getLatitude();
double dLong = location.getLongitude();
double dAlt = location.getAltitude();
textLat.setText(Double.toString(dLat));
textLong.setText(Double.toString(dLong));
textAlt.setText(Double.toString(dAlt));
}
else {
textLat.setText("Fehler");
textLong.setText("Fehler");
textAlt.setText("Fehler");
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(getBaseContext(), "GPS wurde akiviert",
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
Toast.makeText(getBaseContext(), "GPS wurde deaktiviert",
Toast.LENGTH_SHORT).show();
}
};
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 100, 0, ll);
}
}
And in the manifest I added the permissions:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.findlocation_test2">
<uses-permission android:name="android.permission.ACCESS_INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> /**Erlaubnis, um auf die GPS Daten zuzugreifen*/
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

Why listOfFiles is null?

Android says, that listOfFiles if null, so what have i done wrong?
I've tried to change getPath to getAboletePath, but it is just the same.
And, i've tried to access /storage/ (whereas SD_PATH is /storage/emulated/0) and i've got a list of 2 folders: emulated and self, both of wich are unaccessible.
public class MainActivity extends AppCompatActivity {
private static final String SD_PATH = Environment.getExternalStorageDirectory().getPath();
...
File home = new File(SD_PATH);
File[] listOfFiles = home.listFiles();
if(listOfFiles != null && listOfFiles.length > 0){
for (File file : home.listFiles()){
songs.add(file.getName());
}
}
Here is my AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.unimusic">
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

This same thing has burned me in the past.
To quote the docs
Beginning in Android 6.0 (API level 23), users grant permissions to apps while the app is running, not when they install the app.
(see here)
Reading from the file system is one of the permissions that must now be requested at run time in order to use. This is only an issue if you target SDK 23 or later. So how to fix:
The docs show an example (see here for the original) that I have modified for your use case (I have not run this code, but it should be a good starting point). You probably want to request permissions in the onCreate() for the Activity that is going to need the permission (in your case the MainActivity).
// Ask for the read external storage permission
if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)
{
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_EXTERNAL_STORAGE))
{
// Provide an additional rationale to the user if the permission was not granted
// and the user would benefit from additional context for the use of the permission.
// Display a SnackBar with a button to request the missing permission.
Snackbar.make(layout,
"External storage is needed in order to {YOUR EXPLANATION HERE}",
Snackbar.LENGTH_INDEFINITE).setAction("OK", new View.OnClickListener()
{
#Override
public void onClick(View view)
{
// Request the permission
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 0);
}
}).show();
}
else
{
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 0);
}
}