Wait for an launched application to stop - c#

We are currently working on a project in UWP where we have to start an external application to modify some documents.
We looked into the Windows.System.Launcher API but it seems that we need more than what it can offer us.
As we launched the application from a file, we use the LaunchFileAsync method, based on the example given by the MSDN :
async void DefaultLaunch()
{
// Path to the file in the app package to launch
string imageFile = #"images\test.png";
var file = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(imageFile);
if (file != null)
{
// Launch the retrieved file
var success = await Windows.System.Launcher.LaunchFileAsync(file);
if (success)
{
// File launched
}
else
{
// File launch failed
}
}
else
{
// Could not find file
}
}
So far, the example suit us well but we also need to be warned when the user is done with the file. The best would be to be able to give the launcher a callback method.
We haven't found anything like that yet in the documentation. Is this even possible ? Do we need to use another solution ?
TL;DR : Is there a solution to open another application from a UWP app and wait for it to return a result object ?

If the external app is also a UWP app then Launcher.LaunchUriForResultsAsync is designed for this. It will launch the target app then wait for the app to call back with the results.
See Launch an app for results for a full walkthrough of how this works.
If the target app isn't a UWP app then you can implement the same thing yourself: both apps declare a protocol. The client launches the server with the server's protocol. When the server's done it notifies the caller by launching the client's protocol.
You might also want to look into App Services which allow a UWP server app to expose a REST-like service to clients on the local system. 

The app process isolation model means you can't do this from a UWP app. As you just want to know when an arbitrary program has finished you could write this in traditional .net/win32 and include that in your UWP app via the desktop bridge.

Related

Using ASP.NET MVC, is it possible to execute a WPF .exe file after downloading it?

I have an ASP.NET MVC web application with a button to download an .exe file for an existing WPF application. It downloads fine, but when clicked in the browser window, it doesn't execute. How would I fix this?
[HttpGet]
public FileResult downloadFile()
{
var fileName = string.Format("MyApp.exe", DateTime.Today.Date.ToString("dd-MM-yyyy") + "_1");
var tempOutPutPath = Server.MapPath(Url.Content("~/File/")) + fileName;
byte[] finalResult = System.IO.File.ReadAllBytes(tempOutPutPath);
if (System.IO.File.Exists(tempOutPutPath))
System.IO.File.Delete(tempOutPutPath);
if (finalResult == null || !finalResult.Any())
throw new Exception(String.Format("No Files found"));
return File(finalResult, System.Net.Mime.MediaTypeNames.Application.Octet, Path.GetFileName(fileName));
}
This is a security issue, so i would say no. Imagine the disaster if links on malicous sites could download and run programs on the end users pc.
Don't know why you need it, but if you need to launch your wpf app from a browser. Then you could make a link to reference a uri scheme that points to your already installed application. You would have to add it to registry during an install routine or a one time job in your app.
Registering an Application to a URI Scheme in windows 10
Hope this helps
I think this is the closest you can get to run your application from a browser. But making it launch automatically after download is not possible.
like matcsr pointed out what you cannot force a user to execute a file in their download folder. But if what you want is to distribute your WPF app from the web then you need to setup a ClickOnce Web deployment. More info Here: Choose a ClickOnce deployment strategy

UWP How to get PID for app triggred using Launcher?

In my UWP app I use Launcher to open a file(for instance txt) by default app.
bool isFileOpen = await Windows.System.Launcher.LaunchFileAsync(storageFile);
Above method uses default app (for instance notepad.exe) to open a file (for instance txt). Once app gets launched, the new process is created. I would like to know PID and Status of that Process. Why? I want to monitor it's Status to determine if the app (like notepad.exe which opened the file) gets closed.
Is any solution to get those infos like showed in Task Manager?
The LaunchFileAsync method just tells the operating system (OS) to start the default app associated with the specified file. It doesn't know about nor return any PID or other information about the process that eventually gets started by the OS.
So I am afraid you can't get this information without looking at all processes and somehow trying to figure out which ones that were started as a result of your app calling the LaunchFileAsync method. You might for example get all running processes just before you call the method, and then again immediately afterwards. But the API itself doesn't return anything useful in regards to this.

link app with windows service like shut down so that process never end?

link app with windows process so that when user terminated or end the process it says used by another process and also need to insert it into system file like shutdown file using c sharp so that my app never end or terminates
i tried that material but not usefull
this.ShowInTaskbar = false;
I also tried that code in click:
WindowsImpersonationContext ctx = null;
if (!WindowsIdentity.GetCurrent().IsSystem)
{
ctx = WindowsIdentity.Impersonate(System.IntPtr.Zero);
}
string thisuser = WindowsIdentity.GetCurrent().Name;
But have a look at image it is still present in process, what I want is that my process never stops.
what I want is that my process never stops.
To ensure that your process is always running and is started when Windows boots it's easiest to create a windows service instead. It will probably still show up somewhere in task manager and could be killed manually by the user. But windows will try to keep it running.
How to create a service:
https://msdn.microsoft.com/en-us/library/zt39148a(v=vs.110).aspx
And if you need other programs to communicate with your service I find it easy to use a WCF service instead.
https://msdn.microsoft.com/en-us/library/bb386386.aspx

Windows 10 Feedback Task for my App

Similar to this question which invokes the Windows 10 store to allow a user to write a review or rate an app, I'd also like to be able to invoke the Windows 10 Feedback app and allow users to provide feedback there.
I cannot seem to find much information on:
How this works in general. Can any old app use this service? (I
notice it just kind of shows whatever apps I have running)
How to invoke the Windows Feedback app with my package id
In short - not that I can see.
Other apps are invoked via protocol activation. I haven't seen this documented for the feedback app though so I have to err on the side of 'we haven't made this available yet' (I'm still checking though)
Here's an overall guide to the process http://blog.jerrynixon.com/2012/10/walkthrough-using-windows-8-custom.html?m=1
When I look in the registry under HKEY_CLASSES_ROOT\Extensions\ContractId\Windows.Protocol I see (shortened a tad)
[HKEY_CLASSES_ROOT\Extensions\ContractId\Windows.Protocol\PackageId\Microsoft.WindowsFeedback...\ActivatableClassId\App.AppX7eaybq6p4x7d4jgd6w6jk7r5dg6yhmbf.mca\CustomProperties]
"Name"="windows-feedback"
So - give that a try via launching windows-feedback
If I do Windows Key-R (run): windows-feedback://
it works fine so this should work:
var uri = new Uri(#"windows-feedback://");
var success = await Windows.System.Launcher.LaunchUriAsync(uri);
if (success)
{
// URI launched
}
else
{
// URI launch failed
}
Update
I've done some searching and it seems the magic parameter there is
windows-feedback:?contextid=522
That launches the NFL feedback for example. This is a predetermined number - I'm not sure how one gets on this list though.

C# launching an external app with metro api

I am trying to develop an app which launches a regular .exe application from metro app using launcher class. MSDN provided a sample here and a stackoverflow sample is here
The problem is that my metro gives error of "file not found" even the file is there. i have tried to place file on other drives as well but the problem persists
here is my code sample
// Path to the file in the app package to launch
string imageFile = #"E:\App.exe";
var file = await Windows.ApplicationModel.Package.Current.InstalledLocation.GetFileAsync(imageFile);
/* error in the above line .it says file not found The filename, directory name, or volume label syntax is incorrect. (Exception from HRESULT: 0x8007007B)*/
if (file != null)
{
// Launch the retrieved file
var success = await Windows.System.Launcher.LaunchFileAsync(file);
if (success)
{
// File launched
}
else
{
// File launch failed
}
}
else
{
// Could not find file
}
LaunchFileAsync is for launching a file in its default program.
http://msdn.microsoft.com/library/windows/apps/Hh701461
I am not convinced it will work with an .exe
The correct usage is something like:
LaunchFileAsync("images\\picturesofcats.png");
This then opens a picture of cats in your default image viewer.
This will not work for an .exe due to sandboxing, and because .exe has no default opener.
There are a few tricks to get around this, see: Launching a Desktop Application with a Metro-style app
Generally, you are working against the design of Windows 8 to do this, so you might want to reconsider your approach.

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