Flashlight Not Working,when Device Screen Is Off/sleep (android Studio)

i created a flashlight application,flashlight working. but flashlight not work when device screen power is off/sleep. i want flashlight continue on ,when device screen in off/sleep

Solution 1:

Add below code inside if(!isOn) block:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

And the screen will never sleep. Then in the else block of that statement, add below code, which reenables the sleep feature:

getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

If you use onStop() method at the end for turning camera off when user closes the app, add the same code getWindow().clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); In that block too.

Solution 2:

MainActivity.java code 

publicclassMainActivityextendsAppCompatActivity {
ImageButton imageButton;
Camera camera;
Camera.Parameters parameters;
boolean isflash=false;
boolean isOn=false;

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); imageButton=(ImageButton) findViewById(R.id.imageButton); if(getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) { camera=Camera.open(); parameters=camera.getParameters(); isflash=true; } imageButton.setOnClickListener(new View.OnClickListener(){

@OverridepublicvoidonClick(View v){

            if (isflash)
            {
                if (!isOn)
                {
                    imageButton.setImageResource(R.drawable.on);
                    parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
                    camera.setParameters(parameters);
                    camera.startPreview();
                    isOn=true;

                }
                else
                {
                    imageButton.setImageResource(R.drawable.off);
                    parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
                    camera.setParameters(parameters);
                    camera.stopPreview();
                    isOn=false;
                }

            }
            else
            {
                AlertDialog.Builder builder=newAlertDialog.Builder(MainActivity.this);
                builder.setTitle("Error........");
                builder.setMessage("Flashlight is not Available on this device...");
                builder.setPositiveButton("Ok",newDialogInterface.OnClickListener(){
                @OverridepublicvoidonClick(DialogInterface dialog,int which){
                    dialog.dismiss();
                    finish();

                }
            });
                AlertDialog alertDialog=builder.create();
                alertDialog.show();
            }
        }

    });
}

@OverrideprotectedvoidonStop() {
    super.onStop();
    if (camera!=null)
    {
        camera.release();
        camera=null;
    }
}

}