Develop Reference

Capture application-wide exceptions and save to a file/send to internet

I've started to work in a company which has a system with a lot of legacy code. Sometimes we have problems like the application randomly exiting, uncaught exceptions and so on. The compilation works fine and it's hard to know where exactly the error is coming from (either from legacy code or new code), so I'd like to capture exceptions globally in the application and either send them to our servers (best option) or write them to a local file in the device.
Is it possible in Xamarin.Android to write such an interface or method that catches any exception that ever occur in the application and log it to a file? If so, how?

Yes, you can able to handle error globally, by adding some line code in ApplicationStart class, something like below:
[Application(Label = "#string/app_name", Icon = "#drawable/ic_launcher")]
public class ApplicationStart : Application
{
public ApplicationStart(IntPtr handle,
global::Android.Runtime.JniHandleOwnership transfer)
: base(handle, transfer)
{
}
public override void OnCreate()
{
AndroidEnvironment.UnhandledExceptionRaiser += AndroidEnvironmentOnUnhandledExceptionRaiser;
AppDomain currentDomain = AppDomain.CurrentDomain;
currentDomain.UnhandledException += CurrentDomainOnUnhandledException;
base.OnCreate();
}
private void CurrentDomainOnUnhandledException(object sender, UnhandledExceptionEventArgs e)
{
//you can able to write a code here to write Exeption e to file
Toast.MakeText(ApplicationContext, "Application crashed", ToastLength.Short).Show();
}
private void AndroidEnvironmentOnUnhandledExceptionRaiser(object sender, RaiseThrowableEventArgs e)
{
//if you have set e.Handled = true here then when application crashed at any point at that time device not stoped your app to go more
e.Handled = true;
//you can able to write a code here to write Exeption e to file
Toast.MakeText(ApplicationContext, "Application crashed", ToastLength.Short).Show();
}
}

How to call an Android app's method remotely?

I'm working on a project that improves Automation Test for Android's App. What I want to do is very "easy": I have this very simple SIP Client with a basic UI and developed just reading the API guides on the android developer website (https://developer.android.com/guide/topics/connectivity/sip.html) that receives and makes SIP calls.
I need to control remotely this app from my PC, connected at the same local network or the same wifi, by sending commands or similar (without interact with the phone) to the app itslef running normally on my phone.For a specific example I posted the method initiateCall() that calls sipAddress(in the app, sipAddress is taken from a Text Box), what I want to do is:
Starting the app on my phone
calling the method initiateCall() from my pc giving a sipAddress as a parameter (I must not use the UI from the app running, that's why I need to give the sipAddress)
check if an outgoing call starts from the app running on my phone
I thought that the solution must be something about web-services,but I don't have any better ideas and i don't know how to start and where to start solving this problem,that's why i need you help.
public void initiateCall() {
try {
SipAudioCall.Listener listener = new SipAudioCall.Listener() {
// set up the listener for outgoing calls
#Override
public void onCallEstablished(SipAudioCall call) {
call.startAudio();
call.setSpeakerMode(true);
updateStatus(call, 2);
}
#Override
public void onCallEnded(SipAudioCall call) {
updateStatus("Call End");
}
};
call = manager.makeAudioCall(me.getUriString(), sipAddress,
listener, 30);
} catch (Exception e) {
Log.i("WalkieTalkieActivity/InitiateCall",
"Error when trying to close manager.", e);
if (me != null) {
try {
manager.close(me.getUriString());
} catch (Exception ee) {
Log.i("WalkieTalkieActivity/InitiateCall",
"Error when trying to close manager.", ee);
ee.printStackTrace();
}
}
if (call != null) {
call.close();
}
}
}

You could do it REST API style. You would need to set up a minimalistic webserver.
If you access for example the url phoneip/ctrl/makecall?number=yournumber a serverside method us called if set up correctly. Then you can call you method and use the GET or POST variables as arguments.
You would have to look into Java Webserver Libraries/Frameworks. You can pick a lightweight one for that purpose. For example this one.
You could then also add security features (authentification to protect it) quite easily.
Example with sparkjava
import static spark.Spark.*;
....
get("/ctrl/makecall", (request, response) -> {
String phonenum = request.queryParams("number"); //may not be accurate; you have to determine the GET variable called "number" in that case; you can rename it; see docs!!!
//call your method with proper arguments
});

Robotium testcase

I have a Robotium test case and It should be like
UI Application starts uploading data to server
User swaps to some other application on the device
uploading operation is running at the background
user comes to the main UI application
How to keep track of uploading the data at background? can we use multithreading for this?
try {
mSolo.clickOnMenuItem("UPLOAD");
mSolo.sleep(1000);
Instrumentation inst = new Instrumentation();
inst.sendKeyDownUpSync(KeyEvent.KEYCODE_BACK);
mSolo.waitForActivity(Settings.ACTION_APPLICATION_SETTINGS);
mSolo.goBack();
mSolo.assertCurrentActivity("main",
UIActivity.class);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Is this code correct? If not suggest me a modification or correct code.
Help is always appreciated,
Thanks

You cannot interact with other applications unless you signed the third party application with your own key (see black box testing).
But what you can is pressing Home, Back and starting Intents. The following code is untested but hopefully gives you an idea:
try {
mSolo.clickOnMenuItem("UPLOAD"); // start upload
mSolo.sleep(1000);
mSolo.goBack(); // leave app
...
Intent intent = new Intent("com.company.another.app.SomeActivity");
startActivity(inent); // start another app
...
// option one: get app context and use it for access on preferences, etc.
Context context = this.getInstrumentation().getTargetContext().getApplicationContext();
// option two: wait for logs that you write while uploading
solo.waitForLogMessage("Upload completed");
...
Intent intent = new Intent("com.myapp.MyMainUIActivity");
startActivity(inent); // start own Main Activity again
...
} catch (Exception e) {
e.printStackTrace();
}
So you could use log messages, preferences or any other methods of your app in order to follow up the upload progress.

You cannot leave your application and run it again with Instrumentation. This part is not correct:
Instrumentation inst = new Instrumentation();
inst.sendKeyDownUpSync(KeyEvent.KEYCODE_BACK);
Why do you create new instrumentation? You can simply run:
getInstrumentation().sendKeyDownUpSync(KeyEvent.KEYCODE_BACK);
by the way, solo.goBack() just does it, so it doesn't make sense to call it with instrumentation. I would simply rewrite it to:
try {
mSolo.clickOnMenuItem("UPLOAD");
mSolo.sleep(1000);
mSolo.goBack();
assertTrue(mSolo.waitForActivity(Settings.ACTION_APPLICATION_SETTINGS));
mSolo.goBack();
mSolo.assertCurrentActivity("main", UIActivity.class);
} catch (Exception e) {
e.printStackTrace();
}

SDK Android : How to open Shutdown/Reboot dialog for the device

I'm new here.
I have a problem, i try to shutdown a 4.2.2 android device (not root).
I know that ACTION_SHUTDOWN not works with unroot device.
So i want to open the existing shutdown/reboot/airplane dialog, the same we get when we maintain the on/off button. Then the user just have to click shutdown button.
I try to create by this way, without result...
Intent intent = new Intent(Settings.ACTION_DISPLAY_SETTINGS); // or others settings
startActivity(intent);
Thanks,

The is no public sdk access to open the power button menu programatically.
This link has all the approches Here.Simulating power button press to display switch off dialog box

InputManager.getInstance().injectInputEvent(new InputEvent(KeyEvent.KEYCODE_POWER, keyCode), sync);
'sync' becomes either of these:
InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_FINISH
InputManager.INJECT_INPUT_EVENT_MODE_WAIT_FOR_RESULT
and you need
import android.hardware.input.InputManager;
This is untested, but puts you in the right direction, also bare in mind, functionality like this is NOT recommend.
failing that:
public static void simulateKey(final int KeyCode) {
new Thread() {
#Override
public void run() {
try {
Instrumentation inst = new Instrumentation();
inst.sendKeyDownUpSync(KeyCode);
} catch (Exception e) {
Log.e("Exception when sendKeyDownUpSync", e.toString());
}
}
}.start();
}
and simply call it like
simulateKey(KeyEvent.KEYCODE_POWER);

How to join an active session running on a Chromcast device

I have to Users (User A and B) and one Chromecast device (C1).
User B starts a stream on C1.
User A connects to C1
Now User A should be able to control the stream running on C1. But every time I want to start a session the running stream on C1 is shut down and the receiver app is restarting.
Is there a way to join an active session? Or is that a job which has to be done by the web app running on the Chromecast device?
EDIT:
my sender app is a native Android app
Thanks!

You should have a look to the TicTacToe application. I think it does exactly that where 2 players can join the same game :
https://github.com/googlecast/cast-android-tictactoe
Hope this helps.
JN

What sort of sender are you using? Is it a native app (i.e. using Android or iOs SDK on a mobile device) or the sender is a chrome app?

On the receiver, you create a Receiver object and a ChannelHandler. You use the receiver to generate a ChannelFactory which you then pass to the ChannelHandler. The ChannelHandler now handles the creation of channels on the receiver. You will want to add an EventListener to the handler to listen to messages. Based on those messages you can do various things.
receiver = new cast.receiver.Receiver(YOUR_APP_ID, [YOUR_PROTOCOL], "", 5);
var dashHandler = new cast.receiver.ChannelHandler(YOUR_PROTOCOL);
dashHandler.addChannelFactory(receiver.createChannelFactory(YOUR_PROTOCOL));
dashHandler.addEventListener(cast.receiver.Channel.EventType.MESSAGE, onMessage.bind(this));
receiver.start();
...
onMessage = function (e) {
var message = e.message;
switch (message.type) {
...
}
}
On the sender, after a session is created you will want to send a check status message to the receiver to see if there are already channels attached. You can do this via your MessageStream and your receiver needs to respond in such a way that the MessageStream gets its status updated. You check that status to see if there are channels. If there are you can start listening to updates for your receiver. If not you can send a load event to the receiver to start your activity.
MediaProtocolCommand cmd = mMessageStream.requestStatus();
cmd.setListener(new MediaProtocolCommand.Listener() {
#Override
public void onCompleted(MediaProtocolCommand mPCommand) {
if (mMessageStream.getState() == 'channelsExist') {
//Start New Activity
} else {
//Join Existing Activity
}
#Override
public void onCancelled(MediaProtocolCommand mPCommand) {
}
});
This is kind of a vague response, but it could be more specific if I knew what you were trying to do. My app is using Google's RAMP protocol to play videos so my MessageStream and all it's messages are already defined. If you're doing something different, you need to create your own MessageStream.

Sorry for the late answer, but I figured it out by myself: It wasn't such complicated at all
I started the an Application like this
try {
mSession.startSession(applicationName,applicationArgs);
} catch (IllegalStateException e) {
Log.e(getClass().getSimpleName(), e.getMessage(), e);
} catch (IOException e) {
Log.e(getClass().getSimpleName(), e.getMessage(), e);
}
But it seems, that the MimeData applicationArgs is not needed at all. By removing the arguments and starting the session like below it works really fine!
try {
mSession.startSession(applicationName);
} catch (IllegalStateException e) {
Log.e(getClass().getSimpleName(), e.getMessage(), e);
} catch (IOException e) {
Log.e(getClass().getSimpleName(), e.getMessage(), e);
}
I hope this works for you too!