When finding random apk's online through urls, I can successfully download and install them, the user is prompted to ask if they want to install comes up. But when I upload the same apk's to Google drive, and then run the download url from Google drive, the apk's doesn't work. I get a "There was a problem while parsing the package" on the device screen. I put a log to see how much data is being downloaded. And it appears that the apk's being downloaded from google drive are barely the size of what the apk's should be. Around 50k instead of 4MB. I see a lot of questions online about this, but none have talked about Google play not sending the full file. Is there something I'm missing in order to get the full apk downloaded from Google drive? here is the code,
private void downloadApk(){
// checkVersion();
String extStorageDirectory = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString();
File folder = new File(extStorageDirectory);
folder.mkdirs();
File file = new File(folder, "app-debug.apk");
try {
file.createNewFile();
} catch (IOException e1) {
e1.printStackTrace();
}
DownloadApkTask downloadApkTask = new DownloadApkTask(APKURL,file);
downloadApkTask.execute();
}
public class DownloadApkTask extends AsyncTask<String, Void, Void> {
String fileURL;
File directory;
public DownloadApkTask(String fileURL,File directory) {
this.fileURL = fileURL;
this.directory = directory;
}
#Override
protected Void doInBackground(String... params) {
Log.v("DO in Back started","Started");
try {
FileOutputStream f = new FileOutputStream(directory);
URL u = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.connect();
InputStream in = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = in.read(buffer)) > 0) {
Log.v("PROGREsS", String.valueOf(len1));
f.write(buffer, 0, len1);
}
f.close();
directory.setReadable(true,false);
} catch (Exception e) {
System.out.println("exception in DownloadFile: --------"+e.toString());
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void stringReturn) {
super.onPostExecute(stringReturn);
File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)+"/app-debug.apk");
Log.v("STARTING INSTALLATION","-----");
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");
startActivity(intent);
}
}
Based from this page, parsing error occurs on app installment.
When you try to install an application suddenly a window pop-ups saying "there is a problem parsing the package" which means the application cannot be installed due to apk parser i.e. parsing issue.
There are several reasons why this parsing error occurs & definitely one of them is responsible for your parsing error:
File may be downloaded incompletely.
Application might be not suitable for your hardware or OS version.
Due to security issue settings
Corrupted APK file.
Follow the steps shown below for fixing the android parse error on your mobile devices:
Check Manifested app apk file.
Change the Andriomanifest.xml file to its default setting & also check the name of that file. If the original name of the file is “aap.apk” & if you renamed it as "app1.apk" then also it might cause an error. If you have some knowledge of coding, look into the app code if there is some problem with coding.
Security settings.
For the security purpose, the phone has an inbuilt setting that doesn't allow installing applications from a 3rd party provider other than mobile apps provided by play store. Don’t install an app from the non-trusted website. That might really risk your mobile.
Enable USB debugging.
Go to the settings >> Scroll down then, at last, you will see option “About device” select it.
Look for option “build number.”
Tap on “Build number” for 7 times.
You will see a message “you are now a developer.”
Once you enable to go back to settings
Choose “Developer options.”
Tick mark "USB debugging."
Corrupted App file.
The parse error may cause due to corrupted file too. In this case, download a new but complete APK file, & try again to install it again. This might help you.
Disable Antivirus.
If you have installed applications like antivirus & cleaner apps, then this can also prevent some apps installation. This prevention is due to the safety purpose of the handset. They block suspicious downloads from non-trusted sites. If you really want to install that app then disable the antivirus temporarily.
Clear cache cookies of play store.
Open google play store
Select sidebar & choose option “settings.”
In general settings, you will find out to “clear local search history.”
I created a new Xamarin.Forms app to test basic Bluetooth functionality. I downloaded this plugin into both the Android project and the shared project:
https://github.com/aritchie/bluetoothle
I wrote this function in the shared project and am calling it from the OnCreate of my launch activity in my Android project:
public static async Task BroadcastBluetooth()
{
// (I do not await this function when I call it)
try
{
await Task.Delay(5000); // just to make sure we give enough time for all initialization to complete
_server = CrossBleAdapter.Current.CreateGattServer();
// exception thrown on this line
await _server.Start(new AdvertisementData
{
LocalName = "TestServer",
ServiceUuids = new List<Guid>()
});
}
catch (Exception e)
{
}
}
It throws this exception:
{System.NullReferenceException: Object reference not set to an
instance of an object. at
Plugin.BluetoothLE.Server.GattServer.StartAdvertising
(Plugin.BluetoothLE.Server.AdvertisementData adData) [0x00095] in
C:\dev\acr\bluetoothle\Plugin.BluetoothLE.Android\Server\GattServer.cs:135
at Plugin.BluetoothLE.Server.GattServer.Start
(Plugin.BluetoothLE.Server.AdvertisementData adData) [0x00011] in
C:\dev\acr\bluetoothle\Plugin.BluetoothLE.Android\Server\GattServer.cs:70
at App2.App+d__7.MoveNext () [0x00097] in
C:\Projects\app2\App2\App2\App.xaml.cs:49 }
I'm only doing something really basic so I must be missing something? The exception is referencing a directory path of the plugin's developer's machine (C:\dev\acr...) so either this plugin is broken or I'm doing something really wrong?
I am using the same plugin in a current project of mine and it is working fine. So I doubt the issue is within the plugin.
Some thoughts about what could cause the issue:
Are you testing this code on a real device that is capable of performing BLE Advertisement?
Do you have set the permissions accordingly in your android project?
Does BLE Advertising work when you use the native android apis?
It also would be helpful, if you could attach a repository with which I can reproduce the issue.
I have an Android Application that works with locals instalations and I want use it with diferents Parse applications. Each instalation administrator will contract with Parse directly. When app start it will look for the keys for parse.
I wonder how to change the Parse App linkeded in the Android App once this is running
I have tried to call Parse.initialize (context, apllicationId, clientKey) twice but it doesn't work. I have tried the app register in diferent Parse App every time you start the App link with a different Parse App
It´s always linked only with the first application
public void onCreate(final Bundle icicle){
super.onCreate(icicle);
final Context context = this;
setContentView(R.layout.ssa);
getActionBar().hide();
// Getting the global variables
fmGlobalsBean = Utilities.getGlobals(this);
if(!"".equals(fmGlobalsBean.getUrl_server())){
Parse.initialize(contexto, "p4IWkTRc0WTdKkMH6r60hjYzwX1TIXChy8VcDvPb", "KhkcX4G3dqVpRawHyIYfnHAWqj1H2vyhwD3wINlQ");
ParseInstallation.getCurrentInstallation().saveInBackground();
ParsePush.subscribeInBackground(fmGlobalsBean.getUrl_server());
}
else
{
Parse.initialize(this, "Y3xgZ58u4Qcn9TrovFqCOe4PBzhURjXooZ3vDKgB", "ealo3nm4wa4lbJ7KrSR2OSf60DZiUjEUjdUJTQzs");
ParseInstallation.getCurrentInstallation().saveInBackground();
ParsePush.subscribeInBackground("INITIAL");
}
}
How to terminate a Xamarin application from any of the activities?
I have tried both System.Environment.Exit(0) and System.Environment.Exit(1) as well as Finish() and killing all the activities.
It still opens one blank page with default activity name and a black screen.
Is there any specific solution for this?
If you are using Xamarin.Forms create a Dependency Service.
Interface
public interface ICloseApplication
{
void closeApplication();
}
Android : Using FinishAffinity() won't restart your activity. It will simply close the application.
public class CloseApplication : ICloseApplication
{
public void closeApplication()
{
var activity = (Activity)Forms.Context;
activity.FinishAffinity();
}
}
IOS : As already suggested above.
public class CloseApplication : ICloseApplication
{
public void closeApplication()
{
Thread.CurrentThread.Abort();
}
}
UWP
public class CloseApplication : ICloseApplication
{
public void closeApplication()
{
Application.Current.Exit();
}
}
Usage in Xamarin Forms
var closer = DependencyService.Get<ICloseApplication>();
closer?.closeApplication();
A simple way to make it work cross platform is by this command:
System.Diagnostics.Process.GetCurrentProcess().CloseMainWindow();
Got it from this link.
EDIT: After using it for a while, I discovered that .CloseMainWindow() don't kill the application, only Closes it (well, thats obvious). If you want to terminate the app (kill), you shoud use the following:
System.Diagnostics.Process.GetCurrentProcess().Kill();
For Android, you can do
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
iOS explicitly does not provide any API for existing an App. Only the OS can close an App.
For iOS, you can use this code:
Thread.CurrentThread.Abort();
For Android, as #Jason mentioned here:
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
System.Environment.Exit(0);
Works for me.
In your activity, use this code
this.FinishAffinity();
I tried this code
protected override bool OnBackButtonPressed()
{
Device.BeginInvokeOnMainThread(async () =>
{
var result = await DisplayAlert("", "Would you like to exit from application?", "Yes", "No");
if (result)
{
if (Device.OS == TargetPlatform.Android)
{
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
}
else if (Device.OS == TargetPlatform.iOS)
{
Thread.CurrentThread.Abort();
}
}
});
return true;
}
In this, iOS and Android application close when a user chooses to terminate the application. Maybe it helps you.
A simple all-in-one combination of the previous answers, instead of the interface/dependency:
protected override bool OnBackButtonPressed()
{
Device.BeginInvokeOnMainThread(async () =>
{
var result = await this.DisplayAlert("Alert!", "want to exit?", "Yes", "No");
if (result)
{
#if __ANDROID__
var activity = (Android.App.Activity)Forms.Context;
activity.FinishAffinity();
#endif
#if __IOS__
Thread.CurrentThread.Abort();
#endif
}
});
return true;
}
System.Diagnostics.Process.GetCurrentProcess().CloseMainWindow();
System.Diagnostics.Process.GetCurrentProcess().Kill();
None of the methods above helped my Xamarin Android app to completely shut down. I tried to close it from Activity B, having Activity A also open under it.
A clever guy left a trick here.
First call FinishAffinity() in Activity B (closes both activities,
however, the app is still alive in the background)
Then call JavaSystem.Exit(0) to kill the background app (I think it can be replaced with Android.OS.Process.KillProcess(Android.OS.Process.MyPid()); or System.Diagnostics.Process.GetCurrentProcess().Kill();)
My method to close the app:
private void CloseBtn_Click(object sender, EventArgs e){
FinishAffinity();
JavaSystem.Exit(0);
}
As your original question mentions activities, your question is specifically for Android, you should probably update the question title with that in mind to avoid people looking for a cross-platform solution coming here.
For iOS and Android (say in Xamarin Forms) you can just throw an exception, which while being the "heavy handed" approach, will do the job:
throw new Exception();
As this isn't the best user experience and you may only want to use this for iOS because on Android, you are likely to get a system popup telling you the app crashed. However, unlike other iOS methods like calling exit(0) or calling private iOS methods like "terminateWithSuccess" via a selector, it shouldn't fail app store validation purely based on how you do it. They may still fail you because your app tries to terminate itself.
You may want to implement something different specifically for Android, in which case Jason's answer is sufficient, again if not a little on the nose i.e. using this approach may not allow your app to clean itself up:
Android.OS.Process.KillProcess(Android.OS.Process.MyPid());
Either way, you should really question why you need to provide this option. Unlike desktop applications where closing an application is needed because apps reside inside windows which by design allow multi-tasking and are not task orientated, mobile platforms are primarily designed for users to focus on one task at a time. Once the user is finished the task, they should decide to exit this task by clicking the home button, back button or change app (task) button. This really applies to all platforms.
None of these work with Android 8. They all left the app in the background.
I can prove this by pressing the close all button and the app is still there.
For my testing I used a brand new simple Android app and tried all of your answers.
Application.Quit();
I'm assuming you are using C#
Call
public void Quit ();
This will quit the application the correct way without it "crashing".
i want my application should work on specific devices\OS like "Lumia 650"\"windows phone 8", this is my project requirement.
Is it possible ? if yes where should I mention the details ?
It is not a problem to restrict Windows Phone 8. You just need to build it targeting Windows Phone OS 8.0.
For the device model you do something like this in the App.xaml.cs
private void Application_Launching(object sender, LaunchingEventArgs e)
{
var deviceName = DeviceExtendedProperties.GetValue("DeviceName").ToString();
if (!deviceName.Contains("Lumia_650")) // Please check your phone's actual value
Application.Current.Terminate();
}
If you want to show a friendly message before it exits you can move the code to the MainPage.xaml.cs then add the MessageBox.Show(message) part.
This is only possible in code as you can not prevent users from installing the app if the app is meant for that particular OS what that user has. However, once the app is launched you can get the name of the device and do actions accordingly.
You can try this:
var PhoneName = Microsoft.Phone.Info.DeviceStatus.DeviceName;
if(PhoneName == "Not Allowed Phone")
{
MessageBox.Show("You can not use this app");
}
else
{
}