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".
Below link help to open facebook app, If, installed
Launcher.LaunchUriAsync(new Uri("fb://"))
I need to know facebook installed or not like below condition,
if(installed)
{
//my code
}
else
{
"not installed"
};
Thanks
You cannot check if third party apps like Facebook, Soundhound are installed. The only thing that you can check is the list of apps those you published that are installed on the device.
You can try this out,
var success = await Windows.System.Launcher.LaunchUriAsync(new Uri("fb://"));
if (success)
{
// URI launched
}
else
{
// URI launch failed
}
Nop, you can't check whether a third party application is installed unless if it's an application that you developed.
Reference: How to check if user has installed specific app on the WP8 device
I know the Brew application have 3 types: active, suspend & background. Launch one BREW application as active or suspend is very simple. I know in BREW2.0 and later version, there is a new application type can allow we create one application in the background. It will not stay in the application stack and change status by active or resume command. It will always stay in the background no matter what user command system received. In one of my small project, I need to create and launch one background application like this.
Unfortunately, I cannot find a simple example on Qualcomm or Google. Is there any programmer who has encountered the same problem?
Yes, you are right. BREW2.0+ do support background application.
When we initial a background application, just like other normal new application, it can be launched by the brew application interface directly. You also can launch it by ISHELL_StartApplet function.
When you want to put one brew application in the background, you need do it when handle EVT_APP_STOP event and must set dwParam to false. After handling EVT_APP_STOP by this, the application will be put in the background. And if you want to change it to normal application, you need call ishell_StartApplet function to active to itself again.
Example code:
typedef struct _bgApp
{
AEEApplet a;
boolean m_bGoBg;
} bgApp;
switch (eCode)
{
case EVT_APP_START:
if(pMe->m_bGoBg)
ISHELL_CloseApplet(pMe->a.m_pIShell, FALSE);
case EVT_APP_STOP:
if(pMe->m_bGoBg)
*((boolean*) dwParam) = FALSE;
return TRUE;
case EVT_USER:
if(pMe->m_bGoBg)
{
pMe->m_bGoBg = FALSE;
// make applet active
ISHELL_StartApplet(pMe->a.m_pIShell, AEECLSID_BGAPP); }
else
{
pMe->m_bGoBg = TRUE;
// trigger EVT_APP_STOP to send app to background
ISHELL_CloseApplet(pMe->a.m_pIShell, FALSE);
}
return TRUE;
}
There is a limitation of background application. You cannot change the screen or communicate with user directly. Developer should be careful on the memory used by the background application. This is very important.
I am writing a Firefox add-on for Linux users to pass credentials for NTLM authenticated sites.some what similar to AutoAuth which is written using XUL framework
https://addons.mozilla.org/en-us/firefox/addon/autoauth/
my question is how to access Authentication Dialog using Firefox SDK?
With the add-on sdk you don't have XUL overlays so only thing you really can do outside of that is to use the window watcher. Since popup windows are considered windows you'll see them in the onTrack function when they popup in the browser.
This example code watches windows looking for the window location chrome://global/content/commonDialog.xul which is similar to what the autoauth add-on is doing. That dialog is used for a number of auth questions so you'll have to do the additional work of detecting NTLM auth.
var { isBrowser } = require("sdk/window/utils");
var delegate = {
onTrack: function (window) {
if (!isBrowser(window) && window.location === "chrome://global/content/commonDialog.xul") {
// this could be the window we're looking for modify it using it's window.document
}
},
onUntrack: function (window) {
if (!isBrowser(window) && window.location === "chrome://global/content/commonDialog.xul") {
// undo the modifications you did
}
}
};
var winUtils = require("window-utils");
var tracker = new winUtils.WindowTracker(delegate);
With this code you're pretty much at the point of the autoauth add-on's load() function. You can use window.document.getElementById() to access the DOM of that window and alter the elements within it.
NOTE That the window-utils module is deprecated so you'll need to keep up with the SDK as they move from that module to (hopefully) something else similar.
I'm trying to instanciate a plugin made with Firebreath in Internet Explorer 8 but with no luck so far. This is the code that I'm using:
try
{
if(window.ActiveXObject)
{
var plugin = new ActiveXObject("my.plugin");
return true;
}
else
return false;
}
catch(e)
{
return false;
}
This works fine if I put this code in a html page and then open it from disk (also published in my local IIS); but as soon I publish it (it's a facebook application, so, running inside an IFRAME) I get this message (from the catch exception):
Automation server can't create object
I've tried messing around with IE security zones, but nothing happens, always the same message. Is there any workaround for this? I need to be able to get the plugin version (coded inside the plugin).
Thank you!